tag:theconversation.com,2011:/uk/topics/probiotics-2971/articlesProbiotics – The Conversation2024-02-23T12:57:17Ztag:theconversation.com,2011:article/2139262024-02-23T12:57:17Z2024-02-23T12:57:17ZGut microbiome: meet Lactobacillus acidophilus – the gut health superhero<figure><img src="https://images.theconversation.com/files/577544/original/file-20240223-24-46adyy.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5176%2C3445&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Eating yoghurt is one way of getting more _Lactobacillus acidophilus_ into your diet.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-woman-home-eating-yogurt-111275633">Josep Suria/ Shutterstock</a></span></figcaption></figure><p>Your gut is like a bustling city of trillions of microscopic inhabitants – including bacteria. While some of these bacterial inhabitants are villains, causing illness, infection and disease, others are good – supporting our health and keeping things running smoothly. </p>
<p>But one species of bacterium in our gut is so good and does so much for our health, that it might well be compared to a gut superhero. This microbe goes by the name of <em><a href="https://www.cabdirect.org/cabdirect/abstract/19352701869">Lactobacillus acidophilus</a></em>. </p>
<p><em>Lactobacillus acidophilus</em> might sound like a mouthful, but don’t let its long name intimidate you. In simple terms, it’s a tiny bacterium that belongs to a group of microorganisms known for their <a href="https://pubmed.ncbi.nlm.nih.gov/24912386/">probiotic properties</a> – meaning it provides health benefits when consumed in adequate quantities.</p>
<p>This microbe hangs out in your gut (mainly your small intestine) and helps keep things running smoothly. In fact, <em>Lactobacillus acidophilus</em> has an incredible number of important functions.</p>
<p>It acts as a digestion buddy, munching on things you can’t digest entirely – such as certain sugars and fibres. For example, it helps digest foods rich in lactose (such as dairy products like milk, yogurt and cheese), as well as fermentable carbohydrates found in vegetables, fruits and grains. By doing so, <a href="https://pubmed.ncbi.nlm.nih.gov/30468509/">it helps break down your food</a>, making it easier for your body to absorb nutrients.</p>
<p>Since your gut is a delicate ecosystem, <em>Lactobacillus acidophilus</em> plays a crucial role in maintaining the right balance of bacteria by <a href="https://pubmed.ncbi.nlm.nih.gov/22254077/">preventing harmful bacteria</a> from taking over and causing trouble.</p>
<p>This microbe also <a href="https://pubmed.ncbi.nlm.nih.gov/23372900/">strengthens your body’s defence system</a>. It does this by helping your immune cells <a href="https://pubmed.ncbi.nlm.nih.gov/20823239/">communicate better</a> and stay alert so they’re ready to fight off invaders. </p>
<p>And when your stomach is upset or you’re stressed, <em>Lactobacillus acidophilus</em> is the microbe that comes to the rescue, soothing irritation and <a href="https://pubmed.ncbi.nlm.nih.gov/16728323/">helping ease digestive discomfort</a>.</p>
<figure class="align-center ">
<img alt="A man holds his stomach in pain." src="https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">One of the benefits this microbe has is easing digestive problems.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-suffering-stomach-ache-sitting-on-488527312">Antonio Guillem/ Shutterstock</a></span>
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<p>All of these important functions mean <em>Lactobacillus acidophilus</em> is a true friend to your body, and its affects on your health are pretty impressive, with benefits such as:</p>
<ul>
<li><strong>Happy tummies:</strong> By maintaining a balanced gut environment, your stomach will feel <a href="https://pubmed.ncbi.nlm.nih.gov/18274900/">more comfortable</a>, and you have less chance of experiencing tummy troubles such as <a href="https://pubmed.ncbi.nlm.nih.gov/16728323/">diarrhoea</a>, constipation and bloating.</li>
<li><strong>Immune support:</strong> By keeping your gut in tip-top shape, <em>Lactobacillus acidophilus</em> <a href="https://pubmed.ncbi.nlm.nih.gov/19651563/">helps protect you</a> from infections and illnesses. It’s shown to be particularly good at keeping <a href="https://pubmed.ncbi.nlm.nih.gov/23594927/">influenza</a> at bay. </li>
<li><strong>Controlling allergies and inflammation:</strong> Some studies suggest that having a strong colony of <em>Lactobacillus acidophilus</em> in your gut might <a href="https://pubmed.ncbi.nlm.nih.gov/19840300/">reduce the risk of allergies</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/24954372/">inflammation-related conditions</a> (such as eczema). It acts like a natural shield against <a href="https://pubmed.ncbi.nlm.nih.gov/26044853/">sneezing fits and sore joints</a>.</li>
<li><strong>Preserving mental wellbeing:</strong> Believe it or not, your gut health can influence your mood. <em>Lactobacillus acidophilus</em> might play a role in <a href="https://pubmed.ncbi.nlm.nih.gov/29521671/">promoting good mental wellbeing</a>.</li>
</ul>
<p>Given all the important roles that <em>Lactobacillus acidophilus</em> plays in your health, if you’re keen to fill your gut with this microbe you can find it in tasty fermented foods such as <a href="https://www.tandfonline.com/doi/abs/10.1080/10408398.2011.621169?casa_token=q5rNmHVBFjAAAAAA:79FQSbhMoQYMVxrw_WvyFaeHmSR50olvQO8JaGY9ZzluOnYAy_CLWaJhx6J8utAb1F6xgl60gYRN8w">yogurt and kefir</a>. </p>
<h2>A deeper look</h2>
<p>Even though we know a lot about <em>Lactobacillus acidophilus</em>, there’s still much to explore. Scientists are currently digging deeper to understand whether there are <a href="https://pubmed.ncbi.nlm.nih.gov/16875422/">different strains of this microbe</a> – and if each of these strains have unique abilities. </p>
<p>Scientists are also working on tailoring probiotics to a person’s specific needs. Imagine having a <a href="https://www.nature.com/articles/s41564-020-0721-1">personalised probiotic</a> superhero designed just for you. People with inflammatory bowel disease, weakened immune systems, allergies and mental health concerns may benefit from personalised products containing probiotic strains such as <em>Lactobacillus acidophilus</em>, because of the benefits it may have for these issues. </p>
<p>And finally, researchers are continuing to investigate the link between gut health and the brain – with scientists taking a particular interest in investigating how specifically <em>Lactobacillus acidophilus</em> might influence <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445894/">mood and mental wellbeing</a>.</p>
<p><em>Lactobacillus acidophilus</em> is a tiny but mighty superhero in your gut, working hard to keep you healthy and happy. So the next time you enjoy <a href="https://www.tandfonline.com/doi/abs/10.1080/10408398.2011.621169?casa_token=q5rNmHVBFjAAAAAA:79FQSbhMoQYMVxrw_WvyFaeHmSR50olvQO8JaGY9ZzluOnYAy_CLWaJhx6J8utAb1F6xgl60gYRN8w">a yogurt or sip on some kefir</a>, think of it as giving your friendly gut superhero a high-five. </p>
<hr>
<p><em>This article is part of <a href="https://theconversation.com/uk/topics/meet-your-gut-microbes-150943?utm_source=InArticleTop&utm_medium=TCUK&utm_campaign=Health2024">Meet Your Gut Microbes</a>, a series about the rich constellation of bacteria, viruses, archaea and fungi that live in people’s digestive tracts. Scientists are increasingly realising their importance in shaping our health – both physical and mental. Each week we will look at a different microbe and bring you the most up-to-date research on them.</em></p>
<hr><img src="https://counter.theconversation.com/content/213926/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Fermented foods, such as yoghurt and kefir, are great sources of this immune-boosting microbe.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2209352024-02-15T13:34:14Z2024-02-15T13:34:14ZBacteria in your gut can improve your mood − new research in mice tries to zero in on the crucial strains<figure><img src="https://images.theconversation.com/files/569636/original/file-20240116-23-4k79iu.png?ixlib=rb-1.1.0&rect=0%2C0%2C3295%2C2549&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The difference between one mouse's fear and another mouse's calm might be in their gut bacteria.</span> <span class="attribution"><span class="source">Katriel Cho</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p><a href="https://ods.od.nih.gov/factsheets/Probiotics-Consumer/">Probiotics</a> have been getting a lot of attention recently. These bacteria, which you can consume from fermented foods, yogurt or even pills, are linked to a number of <a href="https://my.clevelandclinic.org/health/treatments/14598-probiotics">health and wellness benefits</a>, including reducing gastrointestinal distress, urinary tract infections and eczema. But can they improve your mood, too?</p>
<p>Behavior and mental health are complicated. But the short answer, according to my team’s <a href="https://doi.org/10.1016/j.bbi.2023.11.001">recently published research</a>, is likely yes.</p>
<p>The beneficial bacteria in probiotics become part of a community of other microscopic organisms living in your digestive system called the <a href="https://www.niehs.nih.gov/health/topics/science/microbiome">gut microbiome</a>. Your gut microbiome contains trillions of a diverse range of bacteria, fungi and viruses. </p>
<p><a href="https://doi.org/10.3389/fmicb.2020.02029">Hundreds of species of bacteria</a> are native to the intestinal tract. Each species can be broken down into hundreds of strains that can also be dramatically different from each other in their metabolism, byproducts and environmental preferences.</p>
<p>This bacterial diversity is why not all probiotics are built the same. Many research groups have shown that specific strains of <em>Lactobacillus</em> have <a href="https://doi.org/10.3390/nu15143258">mood-enhancing effects</a>. </p>
<p>But these effects seem to happen only with the right mix of bacteria in the right conditions. For example, a probiotic that can reduce symptoms of stress in someone who is worried about their calculus final may not work in someone with symptoms of post-traumatic stress disorder.</p>
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<a href="https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Yogurt parfair on a tablecloth" src="https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=584&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=584&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575084/original/file-20240212-16-hxn0sy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=584&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The probiotics in your yogurt may play a role in boosting mood.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/shallow-focus-photo-of-clear-drinking-glass-GbCEo-Nwyj4">Tanaphong Toochinda/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Studying mood in mice</h2>
<p>In my work <a href="https://scholar.google.com/citations?user=X8XcETAAAAAJ&hl=en">as a neuroscientist</a>, I study how the gut influences the brain. My team and I recently <a href="https://doi.org/10.1016/j.bbi.2023.11.001">conducted experiments</a> in mice that support the idea that gut microbiota play a role in regulating stress.</p>
<p>So how do you measure the mood of mice? </p>
<p>First, we needed to understand how stressed mice behave. So we placed them under <a href="https://doi.org/10.1016/j.bbi.2023.11.001">short periods of stress</a>: They are restrained for two hours each day, given enough room to move around but not enough to groom or stand up. We envision this as the same type of stress people experience when they’re confined to a car or cubical for hours at a time. </p>
<p>Stressed mice soon exhibited depression- and anxiety-like behaviors, which we measured by monitoring how much time they spent hiding when placed in a new environment or how quickly they try to right themselves when flipped upside down.</p>
<p>While it isn’t surprising that stressed mice hide longer and are slower to right themselves, the power of their poop to change their behavior was. </p>
<p>To see if stressed behavior could be transferred through the microbiome, we used another group of mice that were entirely clean. These mice were free from any bacteria, fungi or viruses and lived in a rubber bubble. They essentially had no microbiome at all.</p>
<p>We exposed them to poop from either stressed mice or normal mice by sprinkling soiled bedding in their enclosures. Microbes from the donor mice started to populate the gut microbiomes of the clean mice.</p>
<p>Within a few weeks, the clean mice exposed to poop from stressed mice started to develop stress- and anxiety-like behavior, even though nothing else had changed. Meanwhile, clean mice exposed to poop from normal mice had no differences in their behavior. This finding suggests that the microbes in poop changed the mice’s behavior.</p>
<h2>Which bacteria affect mood?</h2>
<p>The results of our experiments led us back to our original question: Which bacteria can change your mood? </p>
<p>We started by comparing the microbes in the poop of stressed and normal mice. In our analysis, we found that a group of bacteria called <em>Lactobacillus</em> was greatly reduced in the stressed mice. Research has linked this group of bacteria to <a href="https://doi.org/10.1016/j.bbih.2020.100169">stress reduction</a> before. However, <em>Lactobacillus</em> contains over 170 different species and even more strains. </p>
<p>Currently, the probiotic supplements available to patients are <a href="https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know">unregulated and often untested</a>. In order to reliably get the most effective strains to patients, they need to be properly tested. So we had to come up with a way to test how different strains affect anxious behavior. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Microscopy image of rod-shaped Lactobacillus stained blue" src="https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=358&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=358&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=358&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=450&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=450&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574702/original/file-20240209-28-2yorsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=450&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Lactobacillus</em> are a diverse range of bacteria that can provide potential health benefits in people.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Lactobacillus_paracasei.jpg">Dr. Horst Neve/Max Rubner-Institut via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Instead of tackling this colossal task alone, we created a method that other microbiome scientists can also use to look at this group of bacteria as systematically as possible. </p>
<p>To recreate the same experimental conditions for each species of microbe, we created a group of mice with only six species of bacteria in their microbiome, the <a href="https://doi.org/10.1093/ilar/ilv012">bare minimum needed</a> for normal and healthy development, which did not include <em>Lactobacillus</em>. This way, we could add individual strains of <em>Lactobacillus</em> back into the mice’s gut microbiome and observe the effects of each strain on their behavior and biology. </p>
<p>We’ve <a href="https://doi.org/10.1016/j.bbi.2023.11.001">tested two strains</a> so far: <em>Lactobacillus intestinalis</em> ASF360 and <em>Lactobacillus murinus</em> ASF361. Mice with these two strains of <em>Lactobacillus</em> are more resilient to stress and have quieted neural pathways associated with fear.</p>
<h2>What’s next?</h2>
<p>Our study on how different strains of <em>Lactobacillus</em> affect mood is just the beginning. We hope that our research will open avenues for other scientists to test different probiotics. </p>
<p>While researchers are <a href="https://doi.org/10.1016/j.neubiorev.2019.03.023">reaching a consensus</a> that the bacteria in your digestive tract can influence your mood, and vice versa, there is still a lot of testing to be done in both animals and in people.</p>
<p>Our team is starting to develop ways to systematically test which bacteria may provide the best health outcomes in people and which probiotics are the most effective. In the meantime, give the <em>Lactobacillus</em> in your gut some love through a healthy, probiotics-rich diet.</p><img src="https://counter.theconversation.com/content/220935/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrea Merchak has received funding from the National Institutes of Health (T32 NS115657, F31 AI174782).</span></em></p>The organisms living in your gut microbiome can influence your mental and physical health. Researchers have developed a way to better test for those biological effects.Andrea Merchak, Postdoctoral Associate in Neuroscience, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2163552024-01-16T19:15:14Z2024-01-16T19:15:14ZSpace travel taxes astronauts’ brains. But microbes on the menu could help in unexpected ways<figure><img src="https://images.theconversation.com/files/565638/original/file-20231213-27-4xr8mj.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5991%2C3000&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/smiling-man-astronaut-presents-shawarma-kebab-1128088580">studiostoks/Shutterstock</a></span></figcaption></figure><p>Feeding astronauts on a long mission to Mars goes well beyond ensuring they have enough nutrients and calories to survive their multi-year journey.</p>
<p>Providing astronauts with the right diet is also paramount in supporting their <a href="https://www.frontiersin.org/articles/10.3389/fncir.2023.1170395/full?trk=public_post_comment-text">mental and cognitive health</a>, in a way unlike previous missions.</p>
<p>So we need to radically rethink how we feed astronauts not only on a challenging mission to Mars, which could be on the cards in the late 2030s or early 2040s, but to prepare for possible settlement on the red planet. </p>
<p>That includes acknowledging the role of microbes in mental health and wellbeing, and providing astronauts with the right foods and conditions for a variety of these beneficial microbes to grow. Our research aims to do just that.</p>
<p>Here’s why a healthy balance of microbes is important under such challenging conditions, and how we could put microbes on the menu.</p>
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<strong>
Read more:
<a href="https://theconversation.com/was-going-to-space-a-good-idea-218235">Was going to space a good idea?</a>
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</em>
</p>
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<h2>Why are missions to Mars so challenging?</h2>
<p>Deep space missions will expose humans to immense physical and psychological challenges. These include prolonged isolation from loved ones, extreme space and resource constraints, and the difficulties of microgravity. </p>
<p>Disruption to astronauts’ circadian rhythms, prolonged radiation exposure and dietary changes can also lower their cognitive performance and wellbeing. </p>
<p>The hazardous conditions, combined with the psychological toll of potential spacecraft failures, can all contribute to mental health problems.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-live-in-space-what-weve-learned-from-20-years-of-the-international-space-station-144851">How to live in space: what we've learned from 20 years of the International Space Station</a>
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<h2>Why is diet important for mental health?</h2>
<p>We already know the quality of people’s diet not only influences their physical health, but also their mental and brain health. </p>
<p>Diet quality is <a href="https://www.nature.com/articles/s41380-018-0237-8">consistently and independently linked</a> to the risk of depression or anxiety. Clinical trials <a href="https://pubmed.ncbi.nlm.nih.gov/35441666/">show</a> improving diet quality <a href="https://www.ncbi.nlm.nih.gov/pubmed/30720698">can lead to</a> profound improvements in depression and anxiety symptoms. </p>
<p>Diet also affects the size and function of a specific brain region – the hippocampus – that is crucial to learning and memory, as well as for maintaining <a href="https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-015-0461-x?report=reader">mental health</a>. When even young healthy adults eat “junk” foods, aspects of cognition linked to the hippocampus quickly <a href="https://royalsocietypublishing.org/doi/abs/10.1098/rsos.191338">decline</a>.</p>
<p>On the other hand, research shows a diet containing more and varied plant foods and seafood (which are rich in components called long-chain omega-3 fatty acids and flavonoids) leads to <a href="https://www.nature.com/articles/s41598-022-21927-5">better cognitive performance</a>. This study was conducted in a closed chamber for 45 days, designed to mimic conditions in space.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Plate of salmon on bed of green salad, with lemon slices, on blue wood table" src="https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565649/original/file-20231213-23-owo81l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A diet rich in plant food and seafood might help your brain, but how do you turn that into space food that will go the distance?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/grilled-salmon-vegetables-366852431">Jacek Chabraszewski/Shutterstock</a></span>
</figcaption>
</figure>
<p>Diet can have such consequences by <a href="https://www.ncbi.nlm.nih.gov/pubmed/33144709">altering</a>:</p>
<ul>
<li>immune function</li>
<li>the size and functioning of the hippocampus </li>
<li>chemical messenger (neurotransmitter) systems</li>
<li>how our bodies respond to stress.</li>
</ul>
<p>Diet can also influence the many ways microbes in the gut affect the brain, a link known as the <a href="https://journals.physiology.org/doi/full/10.1152/physrev.00018.2018?rfr_dat=cr_pub">microbiota gut-brain axis</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/essays-on-health-microbes-arent-the-enemy-theyre-a-big-part-of-who-we-are-79116">Essays on health: microbes aren't the enemy, they're a big part of who we are</a>
</strong>
</em>
</p>
<hr>
<h2>Not all foods make the grade</h2>
<p>Space foods need to appeal to a diverse crew and stay nutritious for an extremely long time (likely a three- to five-year mission). They also need to be lightweight and compact enough to fit on the spacecraft.</p>
<p>Once on Mars, challenges include growing fresh food and culturing protein sources. Beyond providing nutrients, we also need to consider providing more recently identified factors including phytonutrients (such as polyphenols), fermentation products and microbes. These will likely be crucial to sustain health and, indeed, life on deep space missions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/humans-are-going-back-to-the-moon-and-beyond-but-how-will-we-feed-them-189794">Humans are going back to the Moon, and beyond – but how will we feed them?</a>
</strong>
</em>
</p>
<hr>
<h2>Why are microbes so important?</h2>
<p>If you’ve seen the film <a href="https://theconversation.com/the-martian-review-science-fiction-that-respects-science-fact-48373">The Martian</a>, you’ll know microbes are a crucial aspect of growing food, and are essential for keeping humans alive and functioning. </p>
<p>We have co-evolved with, and are hosts to, trillions of different microbes that live on our skin and in all our niches and cavities. This includes our mouths, nose, vagina, lungs and – crucially – our gut.</p>
<p>Most of these microbes are bacteria. The largest number are in the gut, where they influence our digestion, metabolism, and immune, endocrine (hormone) and nervous systems.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YB-8JEo_0bI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">What is the human microbiome?</span></figcaption>
</figure>
<p>The relationship between gut microbes and <a href="https://journals.physiology.org/doi/full/10.1152/physrev.00018.2018?rfr_dat=cr_pub">mental health and behaviour</a> goes both ways. Gut microbes influence our mental health and behaviour, and these, in turn, influence our gut microbes. </p>
<p>Other components of our microbiomes – viruses, fungi and even parasites – and the oral and lung microbiome are also linked to mental and <a href="https://journals.physiology.org/doi/full/10.1152/physrev.00018.2018?rfr_dat=cr_pub">brain health</a>. </p>
<p>Importantly, we <a href="https://www.nature.com/articles/s41586-022-05620-1">share microbes</a> with others, including via the exchange of air, which is highly relevant in closed-environment systems such as inside spacecrafts.</p>
<p>So ensuring all astronauts have the healthiest and most diverse of microbes for the whole of the mission is vital.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-some-farts-smell-and-some-dont-and-why-do-some-farts-feel-hot-215064">Curious Kids: why do some farts smell and some don’t? And why do some farts feel hot?</a>
</strong>
</em>
</p>
<hr>
<h2>How could we encourage healthy microbes?</h2>
<p>It’s not just the food itself we have to think about. We also need to think about how we grow the food if we are to support healthy microbiomes. </p>
<p>Indeed, microbes play an essential role in the nutrient and phytochemical content of plants, and the microbes in soil, plants and humans are interconnected. Research published in 2023 confirms bacteria on vegetables and other plant foods find a home in the <a href="https://www.tandfonline.com/doi/abs/10.1080/19490976.2023.2258565">human gut</a>, enhancing microbe diversity. </p>
<p>But current ways of growing foods on spacecraft don’t use natural soil. Standard “vertical farming” methods grow plants in an alternative growth medium – imagine a next-generation hydroponics system. So we may need to add an optimised microbial cocktail to these systems to enhance the health properties of the foods astronauts grow and eat.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Growing tending plants in a vertical farm" src="https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565654/original/file-20231213-19-kwbbo1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This closed chamber mimics how astronauts will grow fresh crops in space.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/technology/tech-transfer-spinoffs/nasa-research-launches-a-new-generation-of-indoor-farming/">NASA</a></span>
</figcaption>
</figure>
<p><a href="https://www.cell.com/cell/fulltext/S0092-8674(22)01515-X?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS009286742201515X%3Fshowall%3Dtrue">Fermented protein</a> from microbes can be quickly produced in a bioreactor on board the spacecraft, even from food waste. Some types have a meat-like flavour and texture, and can provide all the amino acids humans need as well as useful byproducts from the microbes themselves. </p>
<p>Fermentation itself creates thousands of different bioactive molecules, including some vitamins, that have diverse <a href="https://www.tandfonline.com/doi/abs/10.1080/1028415X.2018.1544332">beneficial effects on health</a>, including possible benefits to mental health.</p>
<p>While we don’t yet know what types of fermented foods are possible in space, we could include fermented foods, such as kimchi and sauerkraut, in astronauts’ diets on Earth.</p>
<p>Probiotics and prebiotics as supplements may also be essential. Probiotics are live microbes that have demonstrated health benefits and prebiotics are food for these healthy microbes.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-kombucha-and-how-do-the-health-claims-stack-up-87180">What is kombucha and how do the health claims stack up?</a>
</strong>
</em>
</p>
<hr>
<h2>Benefits on Earth too</h2>
<p>We’re only at the start of learning how to optimise microbes to keep space crews healthy, which is crucial for long space flights and for possible settlement on other planets. </p>
<p>However, this research could have many other applications. We can use what we learn to help create self-sustaining and <a href="https://www.nasa.gov/technology/tech-transfer-spinoffs/nasa-research-launches-a-new-generation-of-indoor-farming/">sustainable food systems</a> on Earth to improve the environment and human health.</p><img src="https://counter.theconversation.com/content/216355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Felice N Jacka is supported by a National Health and Medical Research Council investigator grant (#1194982). She has received: (1) competitive grant/research support from the Brain and Behaviour Research Institute, the National Health and Medical Research Council, Australian Rotary Health, the Geelong Medical Research Foundation, the Ian Potter Foundation, The University of Melbourne; (2) industry support for research from Meat and Livestock Australia, Woolworths Limited, the A2 Milk Company, Be Fit Foods, Bega Cheese; (3) philanthropic support from the Fernwood Foundation, Wilson Foundation, the JTM Foundation, the Serp Hills Foundation, the Roberts Family Foundation, the Waterloo Foundation and; (4) travel support and speakers honoraria from Sanofi-Synthelabo, Janssen Cilag, Servier, Pfizer, Network Nutrition, Angelini Farmaceutica, Eli Lilly, Metagenics, and The Beauty Chef. She is on the Scientific Advisory Board of the Dauten Family Centre for Bipolar Treatment Innovation and Zoe Limited. Felice Jacka has written two books for commercial publication.</span></em></p><p class="fine-print"><em><span>Dorit Donoviel is Executive Director, NASA-Funded Translational (moving products from lab-bench to practice) Research Institute for Space Health at Baylor College of Medicine. Dorit receives funding from NASA through Cooperative Agreement NNX16AO69A and disburses this funding to research groups and companies performing work to safeguard the health of humans in deep space.</span></em></p>Here’s why a healthy balance of microbes is important for astronauts when they travel to Mars and beyond.Felice Jacka, Alfred Deakin Professor, Deakin UniversityDorit Donoviel, Executive Director/Associate Professor, Baylor College of Medicine Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2187442024-01-08T16:43:05Z2024-01-08T16:43:05ZHow to maintain a healthy gut microbiome in 2024<figure><img src="https://images.theconversation.com/files/567608/original/file-20240102-17-7n4kg4.jpg?ixlib=rb-1.1.0&rect=17%2C0%2C5973%2C3988&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/adult-child-hands-holding-intestine-shape-1935965023">SewCreamStudio/Shutterstock</a></span></figcaption></figure><p>We all know by now that the pillars of a healthy lifestyle are regular exercise, eating enough fruit and vegetables, a good night’s sleep and staying hydrated. All of these things also support the gut microbiome – all the microbes that live in your digestive system – but there are some extras to consider if you want to optimise your gut health.</p>
<p>It’s widely accepted among those of us who study the gut microbiome that a healthy gut is one that contains a <a href="https://theconversation.com/diverse-gut-microbiomes-give-better-protection-against-harmful-bugs-now-we-know-why-219734">diverse range of microbes</a> and has an effective gut barrier (the lining between your intestine and bloodstream).</p>
<p>Let’s look at diet first. It probably has the biggest influence on your gut health. Diets high in fibre, unsaturated fatty acids (found in fish and nuts), and polyphenols (chemicals found in plants) will <a href="https://www.annualreviews.org/doi/full/10.1146/annurev-physiol-031522-092054">promote a healthy gut</a>, while those high in saturated fats, additives (such as “E numbers”) and sugar can harm gut health. So avoid consuming a lot of ultra-processed foods.</p>
<p>Emulsifiers, a common additive in ultra-processed foods, have been found to cause <a href="https://www.mdpi.com/2072-6643/14/15/3049">intestinal inflammation and a leaky gut</a>. The most common ones to look out for on packaging are lecithin, polysorbates (such as E433) and carrageenan.</p>
<p>These additives are also common in protein supplements, whose popularity has steadily been increasing since the <a href="https://theconversation.com/decades-of-hype-turned-protein-into-a-superfood-and-spawned-a-multibillion-dollar-industry-163711#:%7E:text=Global%20retail%20sales%20of%20protein,around%20half%20of%20the%20market.">early 2000s</a>, especially among gym goers looking to bulk up. </p>
<h2>Prebiotics and probiotics</h2>
<p>It would be unreasonable and unrealistic to tell you to avoid foods with additives, but trying to limit consumption, while increasing your consumption of prebiotic and probiotic foods, could help protect your gut.</p>
<p>Dietary fibre is a good example of a prebiotic, which is defined as a non-digestible food ingredient that can stimulate the growth of good bacteria <a href="https://www.nature.com/articles/s41575-020-00375-4">in the colon</a>. As the main food source of your gut microbes, it is important to consume enough if you want your microbiome to flourish. Government guidelines suggest around 30g of fibre a day for adults and 15-25g for children. </p>
<figure class="align-center ">
<img alt="Foods that are rich in fibre." src="https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567719/original/file-20240103-25-e1au68.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Adults should aim to consume 30g of fibre a day.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/high-fiber-foods-healthy-balanced-dieting-1916962526">Tatjana Baibakova/Shutterstock</a></span>
</figcaption>
</figure>
<p>Most prebiotics come from plant foods, so getting a high diversity of plant products in your diet will keep your gut healthy. The latest recommendation is to include 30 plant species in your <a href="https://journals.asm.org/doi/10.1128/msystems.00031-18">diet per week</a>. This may sound hard to achieve but bear in mind that both good-quality coffee and dark chocolate count.</p>
<p>Probiotics, the live bacteria and yeasts themselves, can be easily consumed through fermented food products, drinks or supplements. Choosing a high-quality probiotic is important. While there is an increasing amount on the market in supplement, powder and tablet form, they can be expensive. Fermented foods can be just as effective, but a whole lot cheaper. </p>
<p>Yoghurts, cheese, sauerkraut, kimchi and fermented soy products, such as tempeh and miso, are examples of fermented foods that not only support the healthy balance of your gut bacteria but provide a good source of fibres, vitamins and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5425481/">other nutrients</a>. </p>
<p>To get the most benefit from these products, look for those in the fridge section labelled as containing “live cultures” or “live bacteria”, with minimal ingredients and no heating or pasteurisation processing. </p>
<p>Aside from what you eat, how often you eat could also affect your gut health. Fasting can allow repair of the gut lining and <a href="https://www.sciencedirect.com/science/article/pii/S0966842X23000574?via%3Dihub#s0085">reduce inflammation</a>.</p>
<h2>Medication and the microbiome</h2>
<p>Medications can directly and indirectly affect our gut health. You may have heard that antibiotics are bad for your gut microbiome, especially those which are “broad spectrum” and will kill off not only harmful bacteria but beneficial ones too. This can be associated with <a href="https://www.mdpi.com/1422-0067/24/4/3074">gastrointestinal problems and decreased immunity</a>, especially after prolonged use. </p>
<p>Of course, doctors do not prescribe antibiotics lightly, so it is important to take them as instructed. If you are concerned, discuss the potential effects on your gut health with your GP.</p>
<p>Although you may not have much say over which medications you take, there are a few strategies to support your gut during and after medication. </p>
<p>Staying healthy by prioritising good sleep and managing stress levels is also important, but increasing your intake of both <a href="https://www.nature.com/articles/s41467-023-40553-x">prebiotics</a> and <a href="https://journals.sagepub.com/doi/10.1177/20499361231154443">probiotics</a> at this time may <a href="https://www.mdpi.com/1422-0067/24/4/3074">lessen the blow</a> of medication on your microbiome. </p>
<p>It is always recommended you check with your doctor before introducing a probiotic supplement in the rare case that it may not be suitable alongside the treatment. </p>
<p>Microbiome research is continuously shedding new light on the intricate connections between the microbes that live in our gut and our wellbeing. So watch this space. In the meantime, follow the above advice – it will help you maintain a healthy gut microbiome in 2024 and beyond.</p>
<p><em>Correction: An earlier version of this article incorrectly stated that guar and xantham gum are emulsifiers.</em></p><img src="https://counter.theconversation.com/content/218744/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Improve your gut microbiome health and you improve so many aspects of your overall health. Here’s how to do it.Rosie Young, PhD Candidate, Gut Microbes in Health and Disease, Quadram InstituteMariam Gamal El-Din, Visiting Postdoctoral Scientist, Food Microbiome Interactions, Quadram InstituteYang Yue, PhD Candidate in Plants, Food and Health, Quadram InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2192842023-12-19T13:14:58Z2023-12-19T13:14:58ZHow active are the microorganisms in your yogurt? We created a new tool to study probiotic activity — and made it out of cardboard<figure><img src="https://images.theconversation.com/files/565830/original/file-20231214-19-q51cra.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4244%2C2920&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fermented foods can be a good source of probiotics. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/fermented-vegetables-sauerkraut-with-carrots-and-royalty-free-image/1279140719?phrase=probiotic+food&adppopup=true">Yulia Naumenko/Moment via Getty Images</a></span></figcaption></figure><p>Humans have been fermenting food and drinks — everything from kimchi and yogurt to beer and kombucha — for <a href="https://doi.org/10.3390%2Ffoods10112861">more than 13,000 years</a>. </p>
<p>Fermentation – a natural process that uses microorganisms to create alcohols and acids from carbohydrates – can preserve food so it lasts longer, and it can enhance the quality of a food by turning some components into more easily digestible forms. </p>
<p>Some fermented foods that contain live microorganisms are <a href="https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know">called probiotics</a>, which can increase the shelf life of food and provide a range of additional benefits, like promoting a healthy <a href="https://theconversation.com/which-microbes-live-in-your-gut-a-microbiologist-tries-at-home-test-kits-to-see-what-they-reveal-about-the-microbiome-181392">gut microbiome</a> and lowering cholesterol levels.</p>
<p><a href="https://scienceweb.clemson.edu/uacl/">We are</a> <a href="https://scholar.google.com/citations?user=0kmXuxYAAAAJ&hl=en">chemists</a>, and our team wanted to figure out a way to understand which probiotics are the most active in the body. So we developed a cardboard sensor that could monitor the metabolic activity of probiotics.</p>
<h2>Probiotic health benefits</h2>
<p>As they are generally <a href="https://doi.org/10.1086/523331">considered safe</a>, probiotics are also one of the most popular dietary supplements in today’s market, accounting for more than <a href="https://finance.yahoo.com/news/global-probiotics-market-size-worth-075000774.html">US$50 billion</a> per year. </p>
<p><em>Lactobacillus</em>, <em>Bifidobacterium</em> and <em>Saccharomyces</em> are the most common probiotics. For example, food manufacturers use starter cultures of <em><a href="https://www.healthline.com/health/digestive-health/lactobacillus-bulgaricus">Lactobacillus bulgaricus</a></em> and <em><a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/streptococcus-thermophilus">Streptococcus thermophilus</a></em> to clot milk and make yogurt.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Z-DfrsyAMTw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Probiotic-packed foods can help with gut health.</span></figcaption>
</figure>
<p><a href="https://doi.org/10.1038/s41575-019-0173-3">Recent studies</a> have also found that probiotics may prevent the development of harmful bacteria in the body, lower cholesterol levels, reduce constipation, control blood pressure, enhance the production of vitamins, improve calcium absorption and boost the immune system. </p>
<p>However, probiotics can only provide health effects when the microorganisms are alive, meaning they’re metabolically active and <a href="https://www.nature.com/articles/s41575-019-0173-3/figures/1">interacting with the host’s body</a>. So, the type of probiotic, its formulation, and how it’s processed become critically important. </p>
<h2>Analyzing probiotics</h2>
<p>Probiotics grow from individual cells into colonies. Food scientists can study probiotics by counting the number of viable cells – also called colony forming units – in the food to figure out how much they might grow and how active they’ll be. They can also study how probiotics respond to <a href="https://doi.org/10.1016/j.crfs.2021.04.006">a gastric juice made in the lab</a> to simulate how probiotics act in your gut. <a href="https://www.britannica.com/science/human-digestive-system/Gastric-secretion">Gastric juice</a> is the fluid secreted in your stomach during digestion. </p>
<p>But most of these tests are slow and involve expensive instruments and skilled personnel. That’s where our cardboard sensors come in.</p>
<p>Our research team has collaborated with a research <a href="https://www.iq.usp.br/trlcp/">team from Brazil</a> to develop a simple sensor that can measure the <a href="https://doi.org/10.1002/anse.202300056">metabolic activity of probiotic foods</a>. </p>
<p>We built the sensors using standard cardboard and a process called laser scribing. We use a laser to convert a small amount of the cardboard into carbon, making it electrically conductive. We also used gold nanoparticles, which further improve the sensor’s response by decreasing the material’s resistivity.</p>
<p>Lowering the resistivity of the material is important because the sensor detects the metabolic activity of bacteria via a type of chemical reaction called a <a href="https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:chemical-reactions/x2eef969c74e0d802:oxidation-reduction-redox-reactions/a/oxidation-number">redox reaction</a>. It can detect the oxidation of a molecule that is produced by one of the probiotics. </p>
<h2>Sensor findings</h2>
<p>Before testing, the team first calibrated the sensor using a popular probiotic yogurt widely available in U.S. stores as a model. For each test, we only needed to incubate 100 microliters of sample — about 1/50th of a teaspoon — for 10 minutes at room temperature. </p>
<p>Once we calibrated the sensors, we tested how metabolically active the microorganisms present in the sample were. We tested both beer and yogurt and found that the sensors could determine the metabolic activity more accurately than other tests that scientists usually use. </p>
<p><a href="https://doi.org/10.1002/anse.202300056">We also found</a> that the bacteria in the beer we tested, an unfiltered IPA, had more metabolic activity than the yogurts, which were popular brands Siggi’s, Yakult and Activia.</p>
<p>But, before you run to your local brewery, it’s important to note that the sensor only measures the total metabolic activity of the microorganisms present in the sample. It doesn’t detect anything about the type of activity or potential health effects.</p>
<p>While several groups have reported on the potential <a href="https://doi.org/10.3390%2Fnu15040844">health benefits of beer</a>, not all beers will provide these benefits. And keep in mind that a pint of an IPA carries beneficial bacteria, but also a typical alcohol content of between 6% and 8% and 180-200 calories.</p>
<p>Many <a href="https://doi.org/10.1016/j.tifs.2023.06.013">researchers have performed studies in this field</a> using more traditional probiotic foods that contain many of the microorganisms in your gut. Even in these cases, they’ve found that probiotics’ ability to correct specific health issues is probably limited. </p>
<p>Also, considering the way supplements containing probiotics <a href="https://www.forbes.com/sites/linhanhcat/2019/03/13/probiotics/?sh=35d1926719e8">are regulated</a>, it’s hard to say whether the products actually contain the type and amount of viable bacteria advertised on the label.</p>
<p>All things considered, the proposed sensor aims to provide a simple, portable and low-cost way to detect the activity of live bacteria. These sensors could one day help out in fields like health care.</p><img src="https://counter.theconversation.com/content/219284/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Financial support for this project has been provided by the Department of Chemistry at Clemson University and by CAPES (Brazil).</span></em></p><p class="fine-print"><em><span>George Chumanov does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Probiotics are great for your gut, but which sources contain the most beneficial bacteria? Newly developed sensors are helping scientists figure it out.Carlos D. Garcia, Professor of Chemistry, Clemson UniversityGeorge Chumanov, Professor of Chemistry, Clemson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2117482023-09-15T00:56:34Z2023-09-15T00:56:34ZHow can I lower my cholesterol? Do supplements work? How about psyllium or probiotics?<figure><img src="https://images.theconversation.com/files/545897/original/file-20230901-17-zovk4b.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C1908%2C1279&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.pexels.com/photo/white-ceramic-bowls-with-supplements-7615572/">Nataliya Vaitkevich/Pexels</a></span></figcaption></figure><p>Your GP says you have high cholesterol. You’ve six months to work on your diet to see if that’ll bring down your levels, then you’ll review your options. </p>
<p>Could taking supplements over this time help?</p>
<p>You can’t rely on supplements alone to control your cholesterol. But there’s some good evidence that taking particular supplements, while also eating a healthy diet, can make a difference.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/got-high-cholesterol-here-are-five-foods-to-eat-and-avoid-63941">Got high cholesterol? Here are five foods to eat and avoid</a>
</strong>
</em>
</p>
<hr>
<h2>Why are we so worried about cholesterol?</h2>
<p>There are two main types of cholesterol, both affecting your risk of heart disease and stroke. Both types are carried in the bloodstream inside molecules called lipoproteins.</p>
<p><strong>Low-density lipoprotein or LDL cholesterol</strong></p>
<p>This is often called “bad” cholesterol. This lipoprotein carries cholesterol from the liver to cells throughout the body. High levels of LDL cholesterol in the blood can lead to the <a href="https://www.ahajournals.org/doi/full/10.1161/JAHA.118.011433">build-up of plaque</a> in arteries, which leads to an <em>increased</em> risk of heart disease and stroke. </p>
<p><strong>High-density lipoprotein or HDL cholesterol</strong></p>
<p>This is often called “good” cholesterol. This lipoprotein helps remove excess cholesterol from the bloodstream and transports it back to the liver for processing and excretion. Higher levels of HDL cholesterol are <a href="https://www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.119.312617">linked to</a> a <em>reduced</em> risk of heart disease and stroke. </p>
<p>Diet can play a key role in reducing blood cholesterol levels, especially LDL (“bad”) cholesterol. Healthy dietary choices are <a href="https://theconversation.com/got-high-cholesterol-here-are-five-foods-to-eat-and-avoid-63941">well recognised</a>. These include a focus on eating more unsaturated (“healthy”) fat (such as from olive oil or avocado), and eating less saturated (“unhealthy”) fat (such as animal fats) and trans fats (found in some shop-bought biscuits, pies and pizza bases).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cut avocado, glass of olive oil, green herbs and cut lemon on timber background" src="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">You can find unsaturated fat in foods such as olive oil and avocado.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/food-background-fresh-organic-avocado-lime-253287091">Shutterstock</a></span>
</figcaption>
</figure>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-whats-healthier-butter-or-margarine-19777">Health Check: what's healthier, butter or margarine?</a>
</strong>
</em>
</p>
<hr>
<h2>Fibre is your friend</h2>
<p>An additional way to significantly reduce your total cholesterol and LDL cholesterol levels through diet is by eating more <a href="https://theconversation.com/fiber-is-your-bodys-natural-guide-to-weight-management-rather-than-cutting-carbs-out-of-your-diet-eat-them-in-their-original-fiber-packaging-instead-205159">soluble fibre</a>.</p>
<p>This is a type of fibre that dissolves in water to form a gel-like substance in your gut. The gel can bind to cholesterol molecules preventing them from being absorbed into the bloodstream and allows them to be eliminated from the body through your faeces. </p>
<p>You can find soluble fibre in whole foods such as fruits, vegetables, oats, barley, beans and lentils.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fiber-is-your-bodys-natural-guide-to-weight-management-rather-than-cutting-carbs-out-of-your-diet-eat-them-in-their-original-fiber-packaging-instead-205159">Fiber is your body's natural guide to weight management – rather than cutting carbs out of your diet, eat them in their original fiber packaging instead</a>
</strong>
</em>
</p>
<hr>
<h2>Fibre supplements, such as psyllium</h2>
<p>There are also many fibre supplements and food-based products on the market that may help lower cholesterol. These include:</p>
<ul>
<li><p><strong>natural soluble fibres</strong>, such as inulin (for example, Benefiber) or psyllium (for example, Metamucil) or beta-glucan (for example, in ground oats)</p></li>
<li><p><strong>synthetic soluble fibres</strong>, such as polydextrose (for example, STA-LITE), wheat dextrin (also found in Benefiber) or methylcellulose (such as Citrucel)</p></li>
<li><p><strong>natural insoluble fibres</strong>, which bulk out your faeces, such as flax seeds.</p></li>
</ul>
<p>Most of these supplements come as fibres you add to food or dissolve in water or drinks. </p>
<p>Psyllium is the fibre supplement with the strongest evidence to support its use in improving cholesterol levels. It’s been <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413815/">studied</a> in at least 24 high-quality randomised controlled trials.</p>
<p>These trials show consuming about 10g of psyllium a day (1 tablespoon), as part of a healthy diet, <a href="https://www.sciencedirect.com/science/article/pii/S0002916523070107#:%7E:text=Conclusions%3A,mild%2Dto%2Dmoderate%20hypercholesterolemia.">can significantly lower</a> total cholesterol levels by 4% and LDL cholesterol levels by 7%.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Person stirring in psyllium into glass of water, bowl of psyllium next to glass" src="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">You can mix psyllium fibre into a drink or add it to your food.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-adds-spoon-psyllium-fiber-mix-2031428417">Shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-are-you-eating-the-right-sorts-of-fibre-20089">Health Check: are you eating the right sorts of fibre?</a>
</strong>
</em>
</p>
<hr>
<h2>Probiotics</h2>
<p>Other cholesterol-lowering supplements, such as probiotics, are not based on fibre. Probiotics are thought to help lower cholesterol levels via a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352670/">number of mechanisms</a>. These include helping to incorporate cholesterol into cells, and adjusting the microbiome of the gut to favour elimination of cholesterol via the faeces.</p>
<p>Using probiotics to reduce cholesterol is an upcoming area of interest and the <a href="https://www.sciencedirect.com/science/article/abs/pii/S089990071500461X">research</a> is promising. </p>
<p>In a <a href="https://pubmed.ncbi.nlm.nih.gov/29384846/">2018 study</a>, researchers pooled results from 32 studies and analysed them altogether in a type of study known as a meta-analysis. The people who took probiotics reduced their total cholesterol level by 13%.</p>
<p><a href="https://www.tandfonline.com/doi/full/10.3109/07853890.2015.1071872">Other</a> <a href="https://link.springer.com/article/10.1007/s11906-020-01080-y">systematic reviews</a> support these findings.</p>
<p>Most of these studies use probiotics containing <em>Lactobacillus acidophilus</em> and <em>Bifidobacterium lactis</em>, which come in capsules or powders and are consumed daily.</p>
<p>Ultimately, probiotics could be worth a try. However, the effects will likely vary according to the probiotic strains used, whether you take the probiotic each day as indicated, as well as your health status and your diet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-should-healthy-people-take-probiotic-supplements-95861">Health Check: should healthy people take probiotic supplements?</a>
</strong>
</em>
</p>
<hr>
<h2>Red yeast rice</h2>
<p><a href="https://www.nccih.nih.gov/health/red-yeast-rice">Red yeast rice</a> is another non-fibre supplement that has gained attention for lowering cholesterol. It is often used in Asia and some European countries as a complementary therapy. It comes in capsule form and is thought to mimic the role of the cholesterol-lowering medications known as statins.</p>
<p>A <a href="https://www.frontiersin.org/articles/10.3389/fphar.2021.819482/full">2022 systematic review</a> analysed data from 15 randomised controlled trials. It found taking red yeast rice supplements (200-4,800mg a day) was more effective for lowering blood fats known as triglycerides but less effective at lowering total cholesterol compared with statins.</p>
<p>However, these trials don’t tell us if red yeast rice works and is safe in the long term. The authors also said only one study in the review was registered in a major <a href="https://www.clinicaltrials.gov">database</a> of clinical trials. So we don’t know if the evidence base was complete or biased to only publish studies with positive results.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Red yeast rice capsules" src="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=274&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=274&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=274&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=344&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=344&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=344&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Red yeast rice is often used in Asia and some European countries to lower cholesterol.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-yeast-rice-supplement-capsules-on-1625852824">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Diet and supplements may not be enough</h2>
<p>Always speak to your GP and dietitian about your plan to take supplements to lower your cholesterol.</p>
<p>But remember, dietary changes alone – with or without supplements – might not be enough to lower your cholesterol levels sufficiently. You still need to quit smoking, reduce stress, exercise regularly and get enough sleep. Genetics can also play a role.</p>
<p>Even then, depending on your cholesterol levels and other risk factors, you may still be recommended cholesterol-lowering medications, such as <a href="https://jamanetwork.com/journals/jama/fullarticle/2795522">statins</a>. Your GP will discuss your options at your six-month review.</p><img src="https://counter.theconversation.com/content/211748/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lauren Ball works for The University of Queensland and receives funding from the National Health and Medical Research Council, Queensland Health, Mater Misericordia and the Royal Australian College of General Practitioners. She is a Director of Dietitians Australia, a Director of the Darling Downs and West Moreton Primary Health Network and an Associate Member of the Australian Academy of Health and Medical Sciences.</span></em></p><p class="fine-print"><em><span>Emily Burch works for Southern Cross University.</span></em></p>If you try supplements, you still need to eat a healthy diet, exercise, reduce your stress, quit smoking and get enough sleep. Even then, they may still not be enough.Lauren Ball, Professor of Community Health and Wellbeing, The University of QueenslandEmily Burch, Dietitian, Researcher & Lecturer, Southern Cross UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2095062023-07-13T15:38:46Z2023-07-13T15:38:46ZThe bacteria and microbes in your gut can affect your body and mental health – engineering them promises new forms of treatment. Podcast<figure><img src="https://images.theconversation.com/files/536725/original/file-20230711-27-vnioxr.jpg?ixlib=rb-1.1.0&rect=0%2C94%2C7000%2C3898&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The human gut is home to communities of microbes, bacteria and fungi.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>The human body is a complex organism, made up of trillions of cells. But not all of them are human — about half of them are fungi, microbes and bacteria. Scientists are starting to understand how and why these communities — referred to as microbiomes — <a href="https://commonfund.nih.gov/hmp/healthyhuman">are crucial to the functioning of various body systems</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-human-microbiome-is-a-treasure-trove-waiting-to-be-unlocked-118757">The human microbiome is a treasure trove waiting to be unlocked</a>
</strong>
</em>
</p>
<hr>
<p>In this episode of <em><a href="https://theconversation.com/uk/topics/the-conversation-weekly-98901">The Conversation Weekly</a></em>, we speak to three experts who study the gut microbiome: a gastroenterologist, a neuroscientist and a biological engineer. </p>
<p>Their research considers how these microbiomes are important, what the relationship is between microbiomes and well being, and how synthetically engineered microorganisms promise new forms of therapies. </p>
<iframe src="https://embed.acast.com/60087127b9687759d637bade/64b00822e435a60011b984fd" frameborder="0" width="100%" height="190px"></iframe>
<p><iframe id="tc-infographic-561" class="tc-infographic" height="100" src="https://cdn.theconversation.com/infographics/561/4fbbd099d631750693d02bac632430b71b37cd5f/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Partners in health</h2>
<p>Chris Damman is a gastroenterologist and clinical associate professor at the University of Washington, Wash. Damman investigates how microbiomes in the gut — the digestive system from start to finish — communicate with other body systems. He looks at the gut-brain axis, specifically.</p>
<p>Damman points out the importance of the gut microbiome, which “plays an incredibly important role in digesting our food. We have powerful enzymes that our pancreas and our liver and our stomach, our salivary glands make.” he explains. </p>
<p>“But the enzymes that are our bodies can produce only do so much. So the last part of the small intestine, um, and the large intestine, the colon… it’s there that the microbiome is like our partners in health, converting fibre into things like butyrate and other short chain fatty acids.”</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/your-gut-microbiome-may-be-linked-to-dementia-parkinsons-disease-and-ms-144367">Your gut microbiome may be linked to dementia, Parkinson's disease and MS</a>
</strong>
</em>
</p>
<hr>
<p>Studying the composition and balance of the gut microbiome is starting to reveal connections between it and various neurological conditions. Andrea Merchak, an incoming postdoctoral scholar at the University of Florida, studies the gut biome as it affects and is affected by various conditions.</p>
<p>“Somebody with multiple sclerosis is going to have a different microbiome from when they’re perfectly healthy through diagnosis and then through late stages of disease, that microbiome is gonna change.” </p>
<p>Merchak points out that because of the progression of the condition, multiple sclerosis allows scientists to investigate the gut-brain axis.</p>
<p>“It happens over a really long period of time, which means that we have a really long time to intervene, and a really long time to try and stop what’s going on,” Merchak says. “When a person’s first diagnosed, they’re not necessarily at the point of severe disability yet… We can see it early and we can try and stop it.”</p>
<h2>Engineering the biome</h2>
<p>As scientists learn more about the gut biome and its relationship to disease, they’re also starting to figure out ways to impact the gut biome’s composition to produce different, and more healthful, outcomes.</p>
<p>Tae Seok Moon, a biological engineer at Washington University at St. Louis, Mo., looks at how synthetic biology can be employed within the gut. He is developing sensors that can help adjust the composition of the gut biome and various microbe communities within it.</p>
<p>“What I want to do is, there are some enzyme that break down or synthesize serotonin,” he says. “In response to the serotonin level, bacteria would have the ability to control the concentration of serotonin by producing an enzyme that breakdown serotonin if the serotonin level is too high.”</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1402299644428886026"}"></div></p>
<p>Scientists are looking at how manipulating the gut biome can help address various conditions, but Merchak points out that it’s not as straightforward as it sounds.</p>
<p>“We know that if you change what you eat, it changes the composition of your gut microbiome. And so ultimately, if we find beneficial bacteria that we think is going to be promising for a wide swath of people, generally, that’s going to come with a dietary change in order to maintain those populations.”</p>
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<p>This episode was produced and written by Mend Mariwany with assistance from Katie Flood. Mend Mariwany is the executive producer of The Conversation Weekly. Eloise Stevens does our sound design, and our theme music is by Neeta Sarl.</p>
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<p class="fine-print"><em><span>Christopher J. Damman consults for BCD Biosciences and Supergut.</span></em></p><p class="fine-print"><em><span>Tae Seok Moon is affiliated with the Engineering Biology Research Consortium. </span></em></p>In the past two decades, technology has allowed scientists to learn so much more about the human body and its microbiomes. These discoveries may pave the way to new therapies.Nehal El-Hadi, Science + Technology Editor & Co-Host of The Conversation Weekly Podcast, The ConversationMend Mariwany, Producer, The Conversation Weekly, The Conversation Weekly PodcastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2066602023-06-20T17:37:31Z2023-06-20T17:37:31ZInternet of microbiota: could synthetic probiotics help prevent our natural bacteria from going astray?<figure><img src="https://images.theconversation.com/files/532974/original/file-20230620-19-6ltoty.jpg?ixlib=rb-1.1.0&rect=0%2C59%2C1997%2C1353&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Having a healthy _E coli_ community in our intestinal system is essential to good human health.</span> <span class="attribution"><a class="source" href="https://pixabay.com/fr/photos/koli-bact%C3%A9ries-escherichia-coli-123081/">Geralt/Pixabay</a></span></figcaption></figure><p>Animals use chemical substances called <a href="https://www.americanscientist.org/article/how-animals-communicate-via-pheromones">pheromones</a> to communicate with each other and attract mates, mark territory, and signal danger. Plants release volatile organic compounds to attract pollinators and repel predators. Communication using molecules, known as “molecular communication”, is also useful to humans, albeit in a way that goes unnoticed by us – it plays a critical role in the interactions between the trillions of natural bacteria that live in and on our bodies.</p>
<p>Indeed, the <a href="https://www.theguardian.com/news/2018/mar/26/the-human-microbiome-why-our-microbes-could-be-key-to-our-health">human microbiota</a> – the natural bacteria inside the human body – use <a href="https://asm.org/Articles/2020/June/How-Quorum-Sensing-Works">“quorum sensing”</a> molecules to organise themselves and communicate with their human host. The microbiota is crucial for our health since it involves a wide range of physiological processes, including digestion and immune system regulation, besides producing certain hormones and other essential molecules.</p>
<p>Specifically, the gut microbiota directly affects the central nervous system and influences the host’s moods, behaviour, and cognition via the <a href="https://www.healthline.com/nutrition/gut-brain-connection">“gut-brain axis”</a>, a complex network that connects the two through signalling pathways involving molecules. This communication based on exchanges of molecules within the body is essential for maintaining <a href="https://www.livescience.com/65938-homeostasis.html">homeostasis</a> (that is, cell stability), and has been linked to many physiological processes such as neural development and dopamine metabolism. Conversely, when any failure in these communication networks occurs or when the microbiota population is not optimal, it can result in serious conditions, including <a href="https://www.mdpi.com/1422-0067/20/9/2115">autism spectrum disorder</a> and <a href="https://www.nature.com/articles/s41582-022-00681-2">Parkinson’s disease</a>.</p>
<p>Despite the multiplexed benefits of gut microbiota, its population and how well they operate in the body cannot be controlled by humans since they are independent organisms that live within us. To alleviate these issues, a field of research explores human-made alternatives that could substitute for these organisms, making things more controllable and predictable. Recent research has shown that <a href="https://www.bdebate.org/en/news/artificial-bacteria-will-live-our-bodies-treat-certain-diseases-0">artificial bacteria</a>, also called “synthetic probiotics”, could offer a promising new approach to treating gut-brain axis disorders. These artificial bacteria would use molecular communication, as it occurs naturally in living organisms, but here as a bio-inspired communication paradigm that uses molecules to transfer information.</p>
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<figcaption><span class="caption">Molecular communication in a nutshell (Biophysical Communication Engineering Lab).</span></figcaption>
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<h2>What are artificial bacteria?</h2>
<p>Artificial bacteria <a href="https://www.frontiersin.org/articles/10.3389/fbioe.2021.826479/full">can be designed</a> to interact with the gut microbiome and the central nervous system to modulate and interfere with communication networks within these systems. For instance, they can be programmed to produce specific molecules that <a href="https://www.frontiersin.org/articles/10.3389/fbioe.2021.826479/full">modulate the growth and activity of specific bacteria in the gut microbiome</a>, or to produce neurotransmitter-like neuronal signalling molecules that can <a href="https://pubs.acs.org/doi/10.1021/sb5002505">modulate the nervous system’s activity</a>.</p>
<p>Artificial bacteria can also be designed to mimic the function of a type of natural bacteria, who are called <a href="https://www.bbcgoodfood.com/howto/guide/what-are-probiotics-and-what-do-they-do">probiotics</a> and who have beneficial effects on the gut-brain axis: they can restore or maintain the balance of the gut microbiota, which may help to ameliorate the symptoms of gut-related disorders, such as <a href="https://www.nature.com/articles/s41467-022-31171-0">inflammatory bowel disease</a>, <a href="https://www.nature.com/articles/s41467-022-31171-0">infectious diarrhoea</a>, and <a href="https://www.mdpi.com/2072-6643/12/7/1973">irritable bowel syndrome</a>.</p>
<p>The active use of artificial bacteria in the treatment of gut-brain axis-related disorders is projected to make significant breakthroughs. The ability to engineer microorganisms to perform specific functions or behaviours will be a key enabler for <a href="https://pubmed.ncbi.nlm.nih.gov/28976641/">preventing the proliferation of pathogens and achieving homeostasis in the body</a>. For example, by developing artificial bacteria to produce antimicrobial peptides, we can target and kill harmful bacteria with greater precision, avoiding the development of antibiotic resistance. Similarly, by programming artificial bacteria to promote the growth of beneficial microorganisms in the gut, more effective communication between microorganisms can be established, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7137092/">promoting the restoration of homeostasis</a>.</p>
<p>The development of intestinal biosensors and artificial bacteria to detect disease-related biomarkers enables using them as diagnostic tools. However, the first step in developing diagnostic tools is understanding the communication between natural bacteria and the brain. Accordingly, mimicking it via artificial counterparts might eventually help us tackle many conditions, such as mood disorders and autism, in the foreseeable future.</p>
<h2>How to develop artificial bacteria?</h2>
<p>Molecular communication is a bio-inspired communication paradigm that uses molecules to transfer information as it occurs naturally in living organisms, with several analogous examples in nature as exemplified throughout the article. This communication paradigm paves the way for the realisation of various foreseen applications.</p>
<p>In the context of molecular communication, artificial bacteria refers to the development of engineered bacteria that can communicate with each other and human cells at the molecular level. This envisioned organism is nothing but a <a href="https://www.frontiersin.org/articles/10.3389/frcmn.2021.733664/full">network of systems transmitting and receiving, or, in engineering speak, “transceiving” molecules at the microscale or the nanoscale</a>.</p>
<p>This bacteria-based transceiver can send and receive molecular signals inside the human body to further sense and control biological processes in real time. As stated before, envisioned artificial bacteria is a perfect candidate for biomedical applications of nano-communication networks such as diagnosis and treatment of diseases, health monitoring, drug delivery, and bio-hybrid implants. Yet, the design and fabrication of these bio-compatible devices necessitate cross-disciplinary efforts that benefit from the accumulated knowledge in the fields of information and communication theory, nanotechnology, molecular science, and many others. These involve developing energy and molecule-efficient, low-complexity, and reliable communication techniques, as well as realistic molecular communication channel models validated through experiments.</p>
<p>These transceivers can also be designed for developing “lab-on-chip” technologies, which are miniaturised laboratory systems that can be used to perform various diagnostic and analytical tests for the gut-brain axis. Although there is a vast number of ongoing research projects and developed testbeds on this topic, no experiments in living systems have been done. Many ongoing <a href="https://nwcl.ku.edu.tr/axa.html">research projects</a> are actively working toward bringing this paradigm into reality. A notable example is the development of <a href="https://www.nature.com/articles/s41598-021-98609-1">a prototype molecular communication receiver using graphene</a>, a nanomaterial with outstanding biochemical properties, along with the <a href="https://arxiv.org/abs/2304.03824">utilisation of biosensor technology</a>.</p>
<p>These works indicate that practical devices are not too far off on the horizon, and given the pace of technological advances, we are in a good position to envision the production of these devices within a few decades. However, the main hurdle that researchers still face is conducting successful testing within living organisms such as mice, rats or any model organisms. Advancements in molecular communication and synthetic biology will pave the way for the next significant milestone for in vivo experiments that might enable diagnosis tools for many diseases, especially gut-related disorders.</p>
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<p><em>Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the AXA Research Fund has supported nearly 700 projects around the world conducted by researchers in 38 countries. To learn more, visit the site of the AXA Research Fund or follow on Twitter @AXAResearchFund.</em></p><img src="https://counter.theconversation.com/content/206660/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Özgür Barış Akan ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Our microbiota is linked to essential physiological processes, but when its communication falters, our health can suffer. Synthetic probiotics offer a promising approach to treating gut-brain axis disorders.Özgür Barış Akan, Professor in electrical and electronics engineering, University of Cambridge, Koç UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2038552023-04-21T14:53:28Z2023-04-21T14:53:28ZHay fever could be linked to our gut and nose bacteria – and probiotics may help symptoms<figure><img src="https://images.theconversation.com/files/522085/original/file-20230420-15-nvus1a.jpg?ixlib=rb-1.1.0&rect=17%2C0%2C5734%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many people suffer with hay fever.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/handsome-hipster-blowing-his-nose-on-287952305">wavebreakmedia/Shutterstock</a></span></figcaption></figure><p>For many people, spring has brought with it the dreaded symptoms of <a href="https://www.nhs.uk/conditions/hay-fever/">hay fever</a>, such as itchy eyes, sneezing and a stuffy nose. Hay fever is common, affecting <a href="https://europepmc.org/article/med/17153005">up to 42%</a> of people. It occurs when the immune system overreacts to allergens including pollen.</p>
<p>Research suggests there could be a link between <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5378446/">hay fever and the microbiome</a>, the collection of microorganisms that live in and on our bodies. Specifically, the composition of a person’s <a href="https://www.karger.com/Article/Abstract/510536">gut</a> and <a href="https://link.springer.com/article/10.1007/s00405-020-06311-1">nasal microbiomes</a> may play a role in the development of hay fever symptoms. </p>
<p>By exploring this connection, we can identify potential alternative treatments that may help reduce the effects of hay fever on people’s daily lives.</p>
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Read more:
<a href="https://theconversation.com/got-allergies-you-could-be-at-lower-risk-of-catching-covid-188486">Got allergies? You could be at lower risk of catching COVID</a>
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<h2>Hay fever and the microbiome</h2>
<p>Studies have shown that people with hay fever often have <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/all.13812">a less diverse gut microbiome</a> compared to those without the condition. Reduced diversity of gut bacteria can lead to an imbalance in the microbiome, and result in higher levels of inflammation (the body’s immune response to irritants, such as an allergens).</p>
<p>So the fact that reduced diversity of gut bacteria can lead to an increased risk of hay fever makes sense since the gut microbiome plays a key role in <a href="https://akjournals.com/view/journals/030/68/3/article-p135.xml">regulating the immune system</a>, and we know the immune system influences allergies. </p>
<p>The gut microbiome is thought to affect immune system function in several ways, including through the production of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9040132/">short-chain fatty acids</a>. These are produced by gut bacteria during the fermentation of dietary fibre (a part of normal digestion). </p>
<p>Short-chain fatty acids are known to have anti-inflammatory properties. Research has shown that lower levels of two bacterial strains which produce short-chain fatty acids – <em>Bifidobacterium</em> and <em>Lactobacillus</em> – are associated with <a href="https://pubmed.ncbi.nlm.nih.gov/21340202/">an increased risk of hay fever</a>.</p>
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<strong>
Read more:
<a href="https://theconversation.com/hay-fever-why-some-people-suffer-from-it-and-others-dont-202553">Hay fever: why some people suffer from it and others don't</a>
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<p>In addition to the gut microbiome, hay fever also seems to be linked to the <a href="https://www.frontiersin.org/articles/10.3389/fcimb.2022.841995/full">nasal microbiome</a>, the community of microorganisms that inhabit the nasal passages. </p>
<p>The nasal microbiome plays an important role in regulating the immune system and protecting against harmful pathogens that enter our bodies through the nose. Imbalance and reduced diversity of the nasal microbiome can lead to an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8566799/">increased risk of respiratory infections</a> and <a href="https://www.nature.com/articles/s41564-022-01301-x">exacerbation of hay fever symptoms</a>. </p>
<p>Studies have shown that people with hay fever often have a different <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4101129/">composition of their nasal microbiome</a> compared to those without the condition, with more of certain bacteria such as <em><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984262/">Staphylococcus aureus</a></em>. This imbalance in the nasal microbiome can lead to increased inflammation and a higher risk of certain hay fever symptoms.</p>
<h2>The potential role of probiotics and prebiotics</h2>
<p>Probiotics are <a href="https://academic.oup.com/ajcn/article/71/6/1682S/4729644?login=false">live microorganisms</a> which enhance the composition of “good” bacteria in the body. Prebiotics, meanwhile, are fibres that stimulate beneficial bacteria in the gut. Essentially, good bacteria <a href="https://www.healthline.com/nutrition/probiotics-and-prebiotics">feed on prebiotics</a>. Both are important for maintaining a healthy gut microbiome, which plays a crucial role in our overall health.</p>
<p>Several strains of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/alr.21492">probiotic bacteria</a> have been studied in connection to hay fever.</p>
<p>One strain of interest is <em>Lactobacillus acidophilus</em>, which has been found to <a href="https://www.karger.com/Article/Abstract/515352">reduce hay fever symptoms</a> such as congestion, itching and sneezing. Another is <em>Lactobacillus rhamnosus GG</em>, which has shown potential in preventing hay fever development in infants.</p>
<p>Other <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1440-1711.2000.00886.x">strains</a> such as <em><a href="https://www.nature.com/articles/ejcn2012197">Bifidobacterium lactis</a></em>, <em>Bifidobacterium bifidum</em> and <em>Lactobacillus casei</em> have also shown some promise in reducing hay fever symptoms. But further research is needed.</p>
<h2>How does this work?</h2>
<p>Probiotics appear to modulate the immune response and in particular, decrease the production of inflammatory cytokines. These are signalling molecules produced by cells of the immune system that promote inflammation.</p>
<p>For example, <em>Lactobacillus acidophilus</em> can <a href="https://www.sciencedirect.com/science/article/pii/S0022030205727144">decrease the expression of</a> inflammatory cytokines associated with allergic inflammation in the mucous membranes in the nasal cavity. </p>
<p>Similarly, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256161/"><em>Lactobacillus rhamnosus GG</em></a> has been shown to reduce airway hyperresponsiveness (where the airways narrow excessively in response to stimuli), decrease inflammatory cells in the lungs, and reduce inflammatory cytokines.</p>
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<img alt="Six different types of fermented food in jars." src="https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Fermented foods contain probiotics.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/set-fermented-food-great-gut-health-485504767">marekuliasz/Shutterstock</a></span>
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<p>Prebiotics, such as fructo-oligosaccharides, have also been studied for their <a href="https://pubmed.ncbi.nlm.nih.gov/33376575/">potential in hay fever prevention</a>. They’ve been found to increase beneficial gut bacteria such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115998/"><em>Bifidobacterium</em> and <em>Lactobacillus</em></a>. One study showed that fructo-oligosaccharides supplementation in infants <a href="https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/specific-mixture-of-shortchain-galactooligosaccharides-and-longchain-fructooligosaccharides-induced-an-antiallergic-ig-profile-in-infants-at-risk-for-allergy/22B21443140E6A7F6956CC8F733492D0">decreased their risk</a> of developing hay fever. </p>
<h2>Incorporating probiotics and prebiotics</h2>
<p>If you suffer from hay fever, you may want to consider incorporating probiotics and prebiotics into your routine.</p>
<p>Probiotic supplements are widely available in various forms, including capsules, tablets, powders and drinks. It’s important to choose a supplement that contains the specific strains of probiotic bacteria that have been studied in relation to hay fever. These include <em>Lactobacillus acidophilus</em>, <em>Lactobacillus rhamnosus GG</em>, <em>Bifidobacterium lactis</em>, <em>Bifidobacterium bifidum</em> and <em>Lactobacillus casei</em>. </p>
<p>You can also incorporate <a href="https://www.webmd.com/digestive-disorders/ss/slideshow-probiotics">probiotic-rich foods</a> into your diet. These include fermented foods such as yogurt, kefir, sauerkraut, kimchi and kombucha.</p>
<p>As for prebiotics, fructo-oligosaccharides are <a href="https://www.webmd.com/diet/foods-high-in-prebiotic">commonly found in certain foods</a> such as bananas, onions, garlic, asparagus, artichokes and whole grains. Supplements are also available in various forms, including powders and capsules.</p>
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Read more:
<a href="https://theconversation.com/probiotics-regulate-our-immune-system-and-could-help-fight-off-covid-new-research-175470">Probiotics regulate our immune system and could help fight off COVID – new research</a>
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<p>Sometimes, taking probiotics and prebiotics may have <a href="https://www.tandfonline.com/doi/abs/10.1517/14740338.2014.872627">side effects</a>, including digestive discomfort such as gas, bloating and diarrhoea. To minimise these risks, it’s recommended you start with a low dose and gradually increase this over time. It’s also worth consulting a healthcare provider before taking these supplements, especially if you have a medical condition or are on medications.</p><img src="https://counter.theconversation.com/content/203855/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research suggests there could be a link between hay fever and the microbiome. Exploring this connection paves the way for potential treatments.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1996202023-02-16T11:38:00Z2023-02-16T11:38:00ZKourtney Kardashian’s ‘vaginal health gummies’: here’s what the evidence shows<p>Even if I fully agree with Kourtney Kardashian that vaginal health is an important but not sufficiently talked about part of women’s wellbeing, we may have a strikingly different view on how to tackle the problem. </p>
<p>The reality TV star recently launched a vitamin sweet called <a href="https://www.instagram.com/lemme/?hl=en">Lemme Purr</a> to boost the health of your vagina. On her Instagram channel, she says these gummies use pineapple, vitamin C and probiotics to target vaginal health and pH levels that “support freshness and taste”. </p>
<p>Kourtney continues with the selling words “Give your vagina the sweet treat it deserves (and turn it into a sweet treat)”. One of the claims she makes is that the vitamin sweet supports a healthy <a href="https://en.wikipedia.org/wiki/Vaginal_flora">vaginal microflora</a>. As a researcher specialising in the role of vaginal microflora for women’s health, I was curious and wanted to find out which active ingredients this claim is based on.</p>
<p>Lemme Purr contains pineapple extract (probably for its taste), vitamin C (not really needed if you have a balanced diet) and a clinically tested probiotic (<em>Bacillus coagulans</em>). According to the product description, the probiotic has been shown in clinical studies to support vaginal health, freshness and odour. This surprised me – I should know about these studies and effects as this is <a href="https://bookmarkforlag.se/bocker/vulva-fakta-myter-och-livsomvalvande-insikter/">my primary research field</a>. </p>
<p>A healthy vaginal microflora is composed of lactobacilli that keep the pH low and protect us from infections. My colleagues and I never identified <em>Bacillus coagulans</em> as being important for the health of vaginas, even though we have analysed thousands of samples during recent years. From <a href="https://www.nature.com/articles/nature11234">other research groups</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/35501321/">our own results</a>, we know that <em>Lactobacillus crispatus</em> is the species that is associated with vaginal health and female fertility. </p>
<p>As I may have missed something important, I immediately checked what has been published on that probiotic in scientific journals. I found <a href="https://pubmed.ncbi.nlm.nih.gov/36372047/">one systematic review and meta-analysis</a> (a type of analysis where many individual studies are taken together) that mentions <em>Bacillus coagulans</em>. Apparently, it may improve stool frequency and symptoms of constipation, although the authors conclude that more research is needed. </p>
<p>On the topic of women’s vaginal health, I could only find <a href="https://www.wageningenacademic.com/doi/10.3920/BM2019.0048">a single study</a>. There, 70 women with vaginal discomfort reported symptom relief after direct vaginal administration of the probiotic. There is nothing published on the oral administration of the probiotic that could support the claims made by Kourtney. </p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/reel/CoVFrEur4lX/?utm_source=ig_embed\u0026ig_rid=bd94a1a5-2ddc-4398-a083-5f55fb3ce1bc","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Vaginas don’t need fixing</h2>
<p>So it seems likely that vaginal microflora isn’t influenced by so-called vaginal gummies. But I must share another concern. The statement that our vaginas are not good as they are but need to be fixed to please our partner is deeply worrying. </p>
<p>A healthy vagina has its unique odour based on the discharge that contains cells from the mucosal layer of the vaginal walls and the microbes that thrive there. </p>
<p>Also, our hygiene, sweat and underwear can influence this odour. It can be slightly acidic, because of the lactobacilli producing lactic acid, or have a distinctive metallic smell of blood during menses. Still, this individual odour is not unpleasant or something we have to be ashamed of. It is our personal signature that we do not have to hide. </p>
<p>I also need to dispel the myth that pineapples can affect the taste of a vagina. This statement shows a staggering ignorance of how our bodies function. Like any other foods we eat, pineapple will be digested in our gut into the smallest components, such as carbohydrates, amino acids, lipids, vitamins, minerals and other small molecules that are absorbed into our bloodstream and reach all cells and organs in our body. Sorry, but there is no shortcut of pineapple-derived sugars and fragrances to our vagina. </p>
<p>It is also important to note that our vaginas do not need any special care; they are self-cleaning with a continuous discharge. If this discharge has a strong and unpleasant odour, it might be a sign of a vaginal infection that can have serious consequences on your health and fertility.</p>
<p>After I have read up on the content and checked the scientific research, I feel confident to say that vaginal gummies do not add any health benefits for women. It is yet another example that money can be made from women’s insecurity about their bodies. </p>
<p>If you notice that your vaginal discharge has an abnormal smell, you should seek advice from your GP or gynaecologist – not a reality TV star.</p><img src="https://counter.theconversation.com/content/199620/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ina Schuppe receives funding from Ferring Pharmaceuticals and the Swedish Strategic Research Fund.</span></em></p>No, your vagina does not need vaginal health gummies.Ina Schuppe Koistinen, Associate Professor, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1928312023-01-24T13:22:49Z2023-01-24T13:22:49ZParsing which foods are healthy and which are less so isn’t always straightforward – a new rating system aims to demystify the process<figure><img src="https://images.theconversation.com/files/504494/original/file-20230113-22-lolqv7.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5615%2C3741&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The new system generally gives higher scores to fruits, vegetables and minimally processed foods.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/shopping-cart-speeding-down-supermarket-aisle-royalty-free-image/1147480854?phrase=packaged%20foods%20in%20grocery%20store&adppopup=true">RapidEye/iStock via Getty Images Plus</a></span></figcaption></figure><p>Many people aim to start the year off with healthier food choices. But how do you choose between seemingly similar foods, snacks or beverages? How does a bagel with cream cheese compare to toast topped with avocado, for instance? Or a protein-based shake compared to a smoothie packed with fruits? Or two chicken dishes, prepared in different ways?</p>
<p>As nutrition scientists who have spent our entire careers studying how different foods influence health, <a href="https://sites.tufts.edu/foodcompass/about/">our team at Tufts University</a> has created a new food rating system, <a href="https://sites.tufts.edu/foodcompass/">the Food Compass</a>, that could help consumers and others make informed choices about these kinds of questions. </p>
<h2>Food rating systems explained</h2>
<p>Many such systems <a href="https://doi.org/10.1007/s11883-020-00857-5">exist and are widely used</a> around the globe. Each one combines facts about different nutritional aspects of foods to provide an overall measure of healthfulness, which can be communicated to consumers through package labels or shelf tags. They can also be used to help guide product reformulations or socially conscious investment goals for investors.</p>
<p>Examples of common systems include <a href="https://www.iarc.who.int/wp-content/uploads/2021/09/IARC_Evidence_Summary_Brief_2.pdf">Nutri-Score</a> and <a href="http://www.healthstarrating.gov.au/internet/healthstarrating/publishing.nsf/content/home">Health Star Rating</a> – widely used in Europe, the U.K., Australia and New Zealand – and “<a href="https://www.npr.org/sections/thesalt/2016/08/12/486898630/chile-battles-obesity-with-stop-signs-on-packaged-foods">black box” warning label systems</a>, which are increasingly used throughout Latin America.</p>
<p>All such food rating systems have strengths and limitations. Most aim to be simple, using data on just a few nutrients or ingredients. While this is practical, it can omit other important determinants of healthfulness – like the degree of food processing and fermentation and the presence of diverse food ingredients or nutrients like <a href="https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/">omega-3s</a> and <a href="https://www.webmd.com/diet/foods-high-in-flavonoids">flavonoids</a>, plant compounds that offer an array of health benefits.</p>
<p>Some systems also emphasize older nutrition science. For example, nearly all give negative points for total fat, regardless of fat type, and focus on saturated fat alone, rather than overall fat quality. Another common shortcoming is not assessing refined grains and starches, which have <a href="https://www.healthline.com/nutrition/why-refined-carbs-are-bad">similar metabolic harms as added sugars</a> and <a href="https://doi.org/10.1001/jama.2019.13771">represent about one-third of calories</a> in the U.S. food supply. And many give negative points for total calories, regardless of their source. </p>
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<figcaption><span class="caption">Millions of Americans are overweight yet undernourished.</span></figcaption>
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<h2>Enter the Food Compass</h2>
<p>To address each of these gaps, in 2021 our research team created the <a href="https://sites.tufts.edu/foodcompass/">Food Compass</a>. This system assesses 54 different attributes of foods, selected based on the strength of scientific evidence for their health effects. Food Compass maps and scores these attributes across nine distinct dimensions and then combines them into a single score, ranging from 1 (least healthy) to 100 (most healthy). It incorporates new science on multiple food ingredients and nutrients; does not penalize total fat or focus on saturated fat; and gives negative points for processing and refined carbs.</p>
<p>We have now evaluated 58,000 products using Food Compass and found that it generally <a href="https://doi.org/10.1038/s43016-021-00381-y">performs very well</a> in scoring foods. Minimally processed, bioactive-rich foods like fruits, veggies, beans, whole grains, nuts, yogurt and seafood score at the top. Other animal foods, like eggs, milk, cheese, poultry and meat, typically score in the middle. Processed foods rich in refined grains and sugars, like refined cereals, breads, crackers and energy bars, and processed meats fall at the bottom. </p>
<p>We found Food Compass to be especially useful <a href="https://doi.org/10.1038/s43016-021-00381-y">when comparing seemingly similar food items</a>, like different breads, different desserts or different mixed meals. Food Compass also appears to work better than existing rating systems for certain food groups. </p>
<p>For example, it gives lower scores to processed foods that are rich in refined grains and starch and to low-fat processed foods that are often marketed as healthy, like deli meats and hot dogs, fat-free salad dressings, pre-sweetened fruit drinks, energy drinks and coffees. It also gives higher scores to foods rich in unsaturated oils, like nuts and olive oil. Compared with older rating systems, these improvements are more aligned with the latest science on the health effects of these foods.</p>
<p>We also assessed how Food Compass <a href="https://doi.org/10.1038/s41467-022-34195-8">relates to major health outcomes</a> in people. In a national sample of 48,000 Americans, we calculated each person’s individual Food Compass score, ranging from 1 to 100, based on the different foods and beverages they reported eating.</p>
<p>We found that people whose diets scored higher according to Food Compass <a href="https://doi.org/10.1038/s41467-022-34195-8">had better overall health</a> than those with lower scores. This includes less obesity, better blood sugar control, lower blood pressure and better blood cholesterol levels. They also had a lower risk of metabolic syndrome or cancer and a lower risk of death from all causes. For every 10-point higher Food Compass score, a person had about a 7% lower risk of dying. These are important findings, showing that, on average, eating foods with higher Food Compass scores is linked to numerous improved health outcomes.</p>
<h2>Fine-tuning</h2>
<p>While we believe Food Compass represents a significant advance over existing systems, more work is needed before it can be rolled out to consumers.</p>
<p>As one step, we’re investigating how the scoring algorithm can be further improved. For example, we’re considering the most appropriate scoring for food items like certain cereals that are high in whole grains and fiber but are also processed and have added sugar. And we’re looking at the scoring of different egg, cheese, poultry and meat products, which have a wide range of scores but sometimes score a bit lower than may make intuitive sense.</p>
<p>Over the coming year we will be refining and improving the system based on our research, the latest evidence and feedback from the scientific community.</p>
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<figcaption><span class="caption">Whole grains are much better for you than refined grains.</span></figcaption>
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<p>In addition, more research is needed on how a consumer might understand and use Food Compass in practice. For example, it could be added as a <a href="https://www.ncbi.nlm.nih.gov/books/NBK209847/">front-of-pack label</a> – but would that be helpful without more education and context?</p>
<p>Also, while the scoring system ranges from 1 to 100, could it be more accessible if scores were grouped into broader categories? For instance, might a green/yellow/red traffic light system be easier to understand? </p>
<p>And we’re hoping that future Food Compass versions might contain additional criteria to filter foods for people who follow special diets, such as low-carb, paleo, vegetarian, diabetic-friendly, low-sodium and others.</p>
<h2>The big picture</h2>
<p>Food Compass should not be used to replace food-based dietary guidelines and preferences. Raspberries and asparagus score really well – but a diet of only these foods would not be very healthy. People should seek a <a href="https://www.myplate.gov/">balanced diet</a> across different food groups. </p>
<p>To help, Food Compass may be most useful to compare similar products within a food group. For example, someone who prefers eggs for breakfast can look for higher-scoring egg dishes. Those preferring cereal can look for higher-scoring cereals. And even better, Food Compass can help people add other highest-scoring foods to their plate – like veggies and healthy oils to eggs, and fruit and nuts to cereal – to increase the overall health benefits of that meal.</p>
<p>To make use by others as easy as possible, <a href="https://sites.tufts.edu/foodcompass/publications/">we’ve published</a> all the details of the scoring algorithm, and the scores of the products evaluated, so that anyone can take what we’ve done and use it. </p>
<p>Stay tuned – as we complete <a href="https://sites.tufts.edu/foodcompass/research/our-work/">additional research</a>, we believe Food Compass will become an important tool to clear up confusion in the grocery store and help people make healthier choices.</p><img src="https://counter.theconversation.com/content/192831/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dariush Mozaffarian has received research funding from the National Institutes of Health, the Gates Foundation, The Rockefeller Foundation, Vail Innovative Global Research, and the Kaiser Permanente Fund at East Bay Community Foundation; personal fees from Acasti Pharma and Barilla; serves on the scientific advisory board of Beren Therapeutics, Brightseed, Calibrate, Elysium Health, Filtricine, HumanCo, Instacart, January Inc., Perfect Day, Tiny Organics, and (ended) Day Two, Discern Dx, and Season Health; owns stock in Calibrate and HumanCo; and receives chapter royalties from UpToDate. </span></em></p><p class="fine-print"><em><span>Jeffrey B. Blumberg has received research funding from Danone S.A. and USDA and serves on the scientific advisory boards of Advocare International, American Botanical Council, Blueshift Nutrition, Bragg Live Food Products LLC, California Prune Board, California Walnut Commission, Cranberry Institute, Good Pharma LLC, Everly Health, Guiding Stars Licensing Co, January.ai Inc, Segterra Inc, SmartyPants Vitamins, and Vital Technologies Ltd.</span></em></p><p class="fine-print"><em><span>Paul F. Jacques currently receives research funding from the US Department of Agriculture Agricultural Research Service, the National Institutes of Health, and the Institute for the Advancement of Food and Nutrition Science, and has previously received research funding from Danone Nutricia Research. Dr. Jacques is a member of the Danone North America Essential Dairy and Plant-Based Advisory Board, the Grains for Health Foundation Scientific Advisory Committee, and the Bay State Milling Nutrition and Science Advisory Council. </span></em></p><p class="fine-print"><em><span>Renata Micha has received research funding from the National Institute of Health, Gates Foundation and Danone S.A. Dr. Micha is the Chair of the Independent Expert Group for the Global Nutrition Report. </span></em></p>The Food Compass system scores foods based on variables like the amounts of refined grains and sugars, processing and healthful ingredients. People who ate better-scoring foods had better overall health.Dariush Mozaffarian, Dean of Friedman School of Nutrition Science and Policy, Tufts UniversityJeffrey B. Blumberg, Professor Emeritus in Nutrition Science and Policy, Tufts UniversityPaul F. Jacques, Professor of Nutrition Science and Policy, Tufts UniversityRenata Micha, Associate Professor in Human Nutrition, Tufts UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1932382022-10-27T15:28:22Z2022-10-27T15:28:22ZFermented foods and fibre may lower stress levels – new study<figure><img src="https://images.theconversation.com/files/492088/original/file-20221027-18659-el39uc.jpg?ixlib=rb-1.1.0&rect=0%2C9%2C6016%2C3998&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Foods such as kimchi are great to include in a psychobiotic diet.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kimchi-cabbage-cucumber-radish-jar-korean-1543686266">Nungning20/ Shutterstock</a></span></figcaption></figure><p>When it comes to dealing with stress, we’re often told the best things we can do are exercise, make time for our favourite activities or try meditation or mindfulness. </p>
<p>But the kinds of foods we eat may also be an effective way of dealing with stress, according to research published by me and other members of <a href="https://www.ucc.ie/en/apc/">APC Microbiome Ireland</a>. Our latest study has shown that eating more fermented foods and fibre daily for just four weeks had a significant effect on lowering <a href="https://www.nature.com/articles/s41380-022-01817-y">perceived stress levels</a>. </p>
<p><a href="https://www.nature.com/articles/s41579-019-0256-8">Over the last decade</a>, a growing body of research has shown that diet can have a <a href="https://www.nature.com/articles/s41380-021-01360-2">huge impact on our mental health</a>. In fact, a healthy diet may even reduce the risk of <a href="https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0791-y">many common mental illnesses</a>. </p>
<p>The mechanisms underpinning the effect of diet on mental health are still not fully understood. But one explanation for this link could be via the relationship between our brain and our microbiome (the trillions of bacteria that live in our gut). Known as the <a href="https://psychscenehub.com/psychinsights/the-simplified-guide-to-the-gut-brain-axis/">gut-brain axis</a>, this allows the brain and gut to be in constant communication with each other, allowing essential body functions such as digestion and appetite to happen. It also means that the emotional and cognitive centres in our brain are closely connected to our gut.</p>
<p>While previous research has shown stress and behaviour are also <a href="https://www.sciencedirect.com/science/article/pii/S2352289516300509">linked to our microbiome</a>, it has been unclear until now whether changing diet (and therefore our microbiome) could have a distinct effect on stress levels. </p>
<p>This is what our study set out to do. To test this, we recruited 45 healthy people with relatively low-fibre diets, aged 18–59 years. More than half were women. The participants were split into two groups and randomly assigned a diet to follow for the four-week duration of the study.</p>
<figure class="align-center ">
<img alt="A bowl of slices apples." src="https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492089/original/file-20221027-20344-nhnm85.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Participants were told to eat foods high in prebiotic fibres, such as apples.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fresh-red-apples-sliced-bowl-on-1366904762">gowithstock/ Shutterstock</a></span>
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<p>Around half were assigned a diet designed by nutritionist Dr Kirsten Berding, which would increase the amount of prebiotic and fermented foods they ate. This is known as a <a href="https://www.ucc.ie/en/research/spotlight/thepsychobioticrevolution/">“psychobiotic” diet</a>, as it included foods that have been linked to better mental health.</p>
<p>This group was given a one-on-one education session with a dietitian at both the start and halfway through the study. They were told they should aim to include 6-8 servings daily of fruits and vegetables high in prebiotic fibres (such as onions, leeks, cabbage, apples, bananas and oats), 5-8 servings of grains per day, and 3-4 servings of legumes per week. They were also told to include 2-3 servings of fermented foods daily (such as sauerkraut, kefir and kombucha). Participants on the control diet only received general dietary advice, based on the healthy eating <a href="https://www.hse.ie/eng/about/who/healthwellbeing/our-priority-programmes/heal/healthy-eating-guidelines/">food pyramid</a>. </p>
<h2>Less stress</h2>
<p>Intriguingly, those who followed the psychobiotic diet reported they felt less stressed compared with those who followed the control diet. There was also a direct correlation between how strictly participants followed the diet and their perceived stress levels, with those who ate more psychobiotic foods during the four-week period reporting the greatest reduction in perceived stress levels.</p>
<p>Interestingly, the quality of sleep improved in both groups – though those on the psychobiotic diet reported greater improvements in sleep. Other studies have also shown that gut microbes are implicated in <a href="https://www.sciencedirect.com/science/article/pii/S1471491421001854">sleep processes</a>, which may explain this link. </p>
<p>The psychobiotic diet only caused subtle changes in the composition and function of microbes in the gut. However, we observed significant changes in the level of certain key chemicals produced by these gut microbes. Some of these chemicals have been <a href="https://www.sciencedirect.com/science/article/pii/S0149763421001032">linked to mental health</a>, which could potentially explain why participants on the diet reported feeling less stressed.</p>
<p>Our results suggest specific diets can be used to reduce perceived stress levels. This kind of diet may also help to <a href="https://academic.oup.com/advances/article/12/4/1239/6164875?login=true">protect mental health</a> in the long run as it targets the microbes in the gut.</p>
<p>While these results are encouraging, our study is not without its limitations. First, the sample size is small due to the pandemic restricting recruitment. Second, the short duration of the study could have limited the changes we observed – and it’s unclear how long they would last. As such, long-term studies will be needed. </p>
<p>Third, while participants recorded their daily diet, this form of measurement can be susceptible to error and bias, especially when estimating food intake. And while we did our best to ensure participants didn’t know what group they’d been assigned to, they may have been able to guess based on the nutrition advice they were given. This may have affected the responses they gave at the end of the study. Finally, our study only looked at people who were already healthy. This means we don’t understand what effect this diet could have on someone who may not be as healthy. </p>
<p>Still, our study offers exciting evidence that an effective way to reduce stress may be through diet. It will be interesting to know if these results can also be replicated in people suffering from stress-related disorders, such as anxiety and depression. It also adds further evidence to this <a href="https://www.sciencedirect.com/science/article/pii/S0924977X19317237">field of research</a>, showing evidence of an association between diet, our microbiome and our mental health. </p>
<p>So the next time you’re feeling particularly stressed, perhaps you’ll want to think more carefully about what you plan on eating for lunch or dinner. Including more fibre and fermented foods for a few weeks may just help you feel a little less stressed out.</p><img src="https://counter.theconversation.com/content/193238/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Cryan receives funding from Science Foundation Ireland (SFI), Irish Research Council and the Health Research Board. He also receives funding from the Saks-Kavanaugh Foundation. The author receives research funding, has been a consultant and been on the Speakers Bureau of food and pharmaceutical companies in the microbiome, food and neuroscience arena.
</span></em></p>Our latest study adds further evidence that diet and mental health are closely connected.John Cryan, Vice President for Research & Innovation, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1903482022-10-25T22:43:45Z2022-10-25T22:43:45ZWhat are postbiotics and how can they improve our gut health?<figure><img src="https://images.theconversation.com/files/490282/original/file-20221018-22859-g3xky2.jpg?ixlib=rb-1.1.0&rect=0%2C26%2C4493%2C2964&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.pexels.com/photo/photograph-of-a-person-s-hand-picking-vegetables-7341749/">Photo by Alesia Kozik/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Many of us are familiar with probiotics, such as certain yogurts and fermented foods, full of “good” bacteria that can keep the gut healthy.</p>
<p>You might even have heard of prebiotics, foods rich in complex carbohydrates (dietary fibre) that help foster good bacteria in the large intestine. Popular prebiotic foods include oats, nuts and legumes.</p>
<p>But what about postbiotics? What are they and how do they affect our gut health?</p>
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Read more:
<a href="https://theconversation.com/what-should-you-eat-after-youve-been-on-antibiotics-and-can-probiotics-and-prebiotics-get-your-gut-back-to-normal-163363">What should you eat after you've been on antibiotics? And can probiotics and prebiotics get your gut back to normal?</a>
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<a href="https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C1917%2C1267&q=45&auto=format&w=1000&fit=clip"><img alt="A colourful display of fruits and vegetables." src="https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C1917%2C1267&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/489713/original/file-20221014-17-cmyp4e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A diet rich in vegetables and fruits increases the levels of prebiotics in your body.</span>
<span class="attribution"><a class="source" href="https://pixabay.com/photos/fruit-vegetables-market-stall-428057/">Image by Michal Jarmoluk from Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>What is a postbiotic?</h2>
<p>Postbiotics are essentially the by-products of our gut microbiota. In other words, your body <a href="https://www.health.harvard.edu/nutrition/what-are-postbiotics#:%7E:text=So%2C%20what%20are%20postbiotics%3F,the%20growth%20of%20harmful%20bacteria">produces postbiotics</a> <em>after</em> digesting prebiotic and probiotic foods.</p>
<p>Examples of postbiotics include the short-chain fatty acids butyric acid (or butyrate), acetic acid (or acetate) and propionic acid (or propionate).</p>
<p>These molecules are produced when good probiotic bacteria break down dietary fibre from foods such as fruits and vegetables, grains and legumes.</p>
<p>These postbiotic molecules are important for your gut microbiota. Healthy probiotic bacteria thrive on these short-chain fatty acids in our gut. </p>
<p>And some postbiotics can help suppress “bad” bacteria. For example, probiotic bacteria (such as <em>Lactococcus lactis</em>) produce special chemicals called bacteriocins which can <a href="https://www.sciencedirect.com/science/article/pii/S1040842821002171">prevent</a> the colonisation of pathogens like <em>E. coli</em> in the gut. This process is known as “colonisation resistance”.</p>
<p>Microbial fermentation is where microbes in the gut break down complex carbohydrates. Microbial fermentation of <a href="https://pubs.acs.org/doi/pdf/10.1021/acs.jafc.8b04102">plant-based diets</a> (which are rich in polyphenols), in particular, leads to the production of the postbiotic phenylacetic acid. This postbiotic can reduce the growth of harmful <a href="https://academic.oup.com/pcp/article/60/2/243/5289543?login=true">pathogens</a> in the body.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&rect=0%2C26%2C5991%2C3961&q=45&auto=format&w=1000&fit=clip"><img alt="A customers holds a shopping bag while looking at vegetables." src="https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&rect=0%2C26%2C5991%2C3961&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/489716/original/file-20221014-20-oy88m9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A plant-rich diet is good for postbiotic production.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/unrecognizable-customer-near-greens-in-supermarket-7129141/">Photo by Michael Burrows/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Not all postbiotics are good</h2>
<p>Not all postbiotics are heroes, though.</p>
<p>One type of postbiotic is bile acids, which are produced when we eat too many <a href="https://journals.lww.com/co-gastroenterology/Fulltext/2014/05000/Bile_acids_and_the_gut_microbiome.18.aspx">high-fat foods</a>.</p>
<p>Bile acids have been linked to <a href="https://www.nature.com/articles/s41385-019-0162-4">inflammation</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7225675/">colon cancer</a>.</p>
<p>Staying on a high-protein, low-carbohydrate diet for the long term often means people don’t eat enough fibre, which is linked to a <a href="https://academic.oup.com/ajcn/article/93/5/1062/4597729">higher risk</a> of colon cancer.</p>
<p>This may be due to the production of <a href="https://academic.oup.com/ajcn/article/93/5/1062/4597729">hazardous postbiotics</a> like bile acids.</p>
<h2>What’s the link between postbiotics and cancer?</h2>
<p>Our recent <a href="https://www.tandfonline.com/doi/full/10.1080/19490976.2022.2038865">review</a> (led by my colleague Kayla Jaye at Western Sydney University) found short-chain fatty acids – particularly butyrate – have shown promising results against breast and colorectal cancer cells in previous laboratory studies.</p>
<p>One clinical <a href="https://iopscience.iop.org/article/10.1088/1742-6596/1146/1/012037/pdf">study</a> showed colorectal cancer patients produced significantly lower levels of short-chain fatty acids in their gut than healthy participants.</p>
<p>Another <a href="https://link.springer.com/article/10.1007/s10096-020-04036-x">study</a> found the numbers of bacteria that produce short-chain fatty acids were low in premenopausal breast cancer patients. </p>
<p>Some cellular and animal <a href="https://www.mdpi.com/1422-0067/23/16/9490/htm">studies</a> have also reported that the postbiotic butyrate can help chemotherapy work better against breast cancer and regulate the immune system.</p>
<p>As <a href="https://academic.oup.com/ajcn/article/93/5/1062/4597729">reported</a> in epidemiological studies, a fibre-rich diet, particularly whole grains, can lower the risk of colorectal cancer. This is mainly because fibre-rich diets lead to the production of short-chain fatty acids in the colon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two bags of legumes sit on a kitchen bench." src="https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/490285/original/file-20221018-15124-ybay5v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The best way to improve the levels of good postbiotics is to consume more vegetables, fruits, legumes, wholegrain bread, nuts and seeds.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/high-angle-shot-of-cereal-and-beans-inside-of-white-plastic-5843562/">Photo by Karolina Grabowska/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>OK great, so what do I eat to get more postbiotics in my gut?</h2>
<p>Dietary fibre is the key. </p>
<p>Women and men should consume at least <a href="https://www.monash.edu/medicine/ccs/gastroenterology/prebiotic/faq">25 and 30 grams</a> of fibre, respectively, every day. But few Australians meet this recommendation. </p>
<p>The best way to improve the levels of good postbiotics is to consume more vegetables, fruits, legumes, wholegrain bread, nuts and seeds.</p>
<p>Jerusalem artichokes, garlic, onion, leek and asparagus are fantastic prebiotic vegetables.</p>
<p>A diet rich in fruits and vegetables increases the levels of postbiotics like short-chain fatty acids in the gut. It also helps reduce <a href="https://journals.asm.org/doi/10.1128/msystems.01174-21">bile acids</a>.</p>
<p>Gut health is all about diversity, which means eating a variety of fruits, vegetables, legumes and whole grains to support healthy gut microbiota. </p>
<p>You can also include fermented foods like sauerkraut and kimchi in your diet. These fermented foods have both prebiotic fibre and live probiotic bacteria, which can help produce healthy postbiotics in the gut. </p>
<p>Of course, further research is needed. But to ensure good gut health, you should include plenty of fruits, vegetables and legumes in your diet.</p><img src="https://counter.theconversation.com/content/190348/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deep Jyoti Bhuyan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Your body produces postbiotics after digesting prebiotic and probiotic foods – and many postbiotics are crucial to good gut health.Deep Jyoti Bhuyan, Research Fellow in Healthy Ageing, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1863572022-07-05T09:56:20Z2022-07-05T09:56:20ZMyrkl: new anti-hangover pill said to break down up to 70% of alcohol in an hour – what you need to know<figure><img src="https://images.theconversation.com/files/472460/original/file-20220705-13-sc4t9w.jpg?ixlib=rb-1.1.0&rect=0%2C1%2C1000%2C664&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/drunk-people-party-777424762">Rawpixel/Shutterstock</a></span></figcaption></figure><p>A new anti-hangover supplement has just <a href="https://www.telegraph.co.uk/news/2022/07/04/hangover-prevention-pill-breaks-alcohol-body-goes-sale/">gone on sale</a> in the UK. It is marketed by Swedish firm Myrkl as “the pre-drinking pill that works”.</p>
<p>The pill is said to break down up to 70% of alcohol after 60 minutes. This means that if someone drinks 50ml of 40% spirits, which contains 20ml of pure alcohol, as little as 6ml of the alcohol will enter the bloodstream. This is the same as the person only drinking 15ml of spirits. </p>
<p>This reduction in the amount of alcohol absorbed by the body is mirrored by a reduction in the short-term effects of alcohol, such as euphoria and reduced anxiety. </p>
<p>The company that makes this supplement recommends that two pills are taken one to 12 hours before drinking alcohol.</p>
<p>The probiotic supplement contains two gut-friendly bacteria – <em>Bacillus subtilis</em> and <em>Bacillus coagulans</em> – produced from fermented rice bran. These bacteria naturally break down alcohol into water and carbon dioxide. An acid-resistant capsule protects the bacteria from the stomach’s natural acids so they can reach the intestine where most alcohol is absorbed into the bloodstream.</p>
<h2>What the science says</h2>
<p>The pill is aimed at those who do not want a hangover after drinking the day before. But can these pills really prevent a hangover? </p>
<p>A hangover is mainly due to the <a href="https://www.mayoclinic.org/diseases-conditions/hangovers/symptoms-causes/syc-20373012">dehydrating effects of alcohol</a>, which can give a headache. The direct effect of alcohol on the stomach can also cause a sore stomach and nausea. If less alcohol is taken into the body, the risks of being dehydrated are less. But since the pills only work after alcohol has passed through the stomach to the intestine, they will not stop alcohol’s effect on the stomach.</p>
<figure class="align-center ">
<img alt="A man holds his stomach in pain." src="https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/472493/original/file-20220705-20-bhtg7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The pills won’t stop alcohols effect on the stomach.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/abdominal-pain-headache-unhappy-black-man-1619920417">Prostock-studio/Shutterstock</a></span>
</figcaption>
</figure>
<p>The evidence for Myrkl is based on a <a href="https://journals.sagepub.com/doi/pdf/10.1177/11786388221108919">single published research study</a>. Twenty-four healthy young white adults were asked to take either two Myrkl pills or dummy pills (placebo) each day for seven days. They were then given a small amount of alcohol (between 50 and 90ml of spirits) based on their weight. Their blood alcohol level was tested for the next two hours. </p>
<p>The researchers found that within the first 60 minutes, the amount of alcohol in the blood was 70% lower in those who received Myrkl compared with the dummy pill.</p>
<p>Although this study was well designed, including randomly allocating people to the Myrkl or dummy pill groups, several problems make the results weaker. First, the researchers only reported results from 14 of the 24 people because ten had lower blood alcohol levels at the start. </p>
<p>Second, results varied between different people, which reduces the accuracy of the study. And third, the researchers tested seven days of treatment before a single drink of alcohol, but the company recommend only two pills one to 12 hours before drinking any amount.</p>
<p>The study also leaves many unanswered questions. Does the pill work in people who are not young, healthy and white? Does it work in people with gut or liver disease? Are there differences in the effect of the pill between men and women? What happens when food and alcohol are taken together? Do medications change the action of the pills?</p>
<p>It is already known that friendly gut bacteria are changed by <a href="https://www.nature.com/articles/s41467-020-18871-1">long-term illnesses and lifestyle</a> (smoking, regular alcohol consumption and diet). It is also known that alcohol is absorbed differently according to <a href="https://pubmed.ncbi.nlm.nih.gov/1930365/">weight, sex, physical activity and food consumption</a>. These factors may reduce or increase the effect of the friendly bacteria in the Myrkl pills.</p>
<p>Probiotics are safe and widely available. They can be bought as yoghurts, drinks or pills from many supermarkets and health food shops. The two bacteria in the Myrkl pills are also likely to be safe for most people. Yet probiotics given to people with illnesses can upset the natural balance of healthy gut bacteria causing <a href="https://pubmed.ncbi.nlm.nih.gov/25922398/">infection or gut symptoms</a>.</p>
<p>A pre-drinking pill to prevent the hangover the next day would be of benefit to some people. However, with all the unanswered questions around Myrkl, the best cure for a hangover remains drinking less alcohol the day before.</p><img src="https://counter.theconversation.com/content/186357/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ashwin Dhanda does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Could a new probiotic supplement really cure your hangover?Ashwin Dhanda, Honorary Associate Professor, Hepatology, University of PlymouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1762512022-02-09T00:36:40Z2022-02-09T00:36:40ZA gutful of lunchbox hype – has selling ‘good bugs not drugs’ for kids’ health gone too far?<figure><img src="https://images.theconversation.com/files/444977/original/file-20220208-19-1hp3d6q.jpg?ixlib=rb-1.1.0&rect=46%2C0%2C5184%2C3445&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Does your child have a “<a href="https://kidsinadelaide.com.au/build-a-gut-friendly-lunchbox/">gut-friendly</a>” lunchbox? It’s <a href="https://www.healthylunchboxweek.org.au/">Healthy Lunchbox Week</a>, a back-to-school initiative of Nutrition Australia. School lunches are essential for long-term child health and well-being, according to <a href="http://www.thechildrensclinicpa.com/blog/2021/9/24/strength-in-numbers-how-nutrition-can-build-an-army-to-protect-us-against-covid-19">some researchers</a>.</p>
<p>There are even <a href="https://www.sbs.com.au/language/english/audio/five-tips-to-boost-your-child-s-immune-system-against-covid-19">media</a> <a href="https://www.theguardian.com/society/2021/jul/11/unlocking-the-gut-microbiome-and-its-massive-significance-to-our-health">reports</a> that a “gut-friendly” lunchbox might help protect us against COVID-19.</p>
<p>Many products are now heavily marketed as promoting gut health. How can parents, carers and schools navigate these claims in deciding what children should eat?</p>
<h2>What is a gut-friendly lunch?</h2>
<p>In recent years, microbiome scientists and nutritionists have drawn attention to the interaction between our diet, the <a href="https://theconversation.com/essays-on-health-microbes-arent-the-enemy-theyre-a-big-part-of-who-we-are-79116">colony of microbes</a> in our gut (microbiota), and our health. We have moved beyond the simple idea of nutrition and health as “<a href="https://www.betterhealth.vic.gov.au/health/healthyliving/energy-in-and-energy-out">energy in, energy out</a>”. Instead, human-gut microbiome research understands our bodies as members of and hosts to multispecies communities. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YB-8JEo_0bI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">What exactly is the human microbiome?</span></figcaption>
</figure>
<p>A gut-friendly diet consists of foods that build healthy microbiota. Foods with “friendly” or “good” bacteria – yoghurt, kimchi, sourdough and kombucha, for example – are claimed to promote the microbiota colony in our gut, thereby improving overall health.</p>
<p>Excitement surrounding this research is based upon the hope that your gut microbiome might hold the <a href="https://www.theguardian.com/society/2021/jul/11/unlocking-the-gut-microbiome-and-its-massive-significance-to-our-health">key for countering a range of diseases</a> and conditions. The benefits include better heart health, lower risks of diabetes and obesity, and decreases in depression and anxiety. Some also claim healthy gut microbiota <a href="http://www.thechildrensclinicpa.com/blog/2021/9/24/strength-in-numbers-how-nutrition-can-build-an-army-to-protect-us-against-covid-19">could help fight COVID and other infectious diseases</a> by boosting the immune system.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/essays-on-health-microbes-arent-the-enemy-theyre-a-big-part-of-who-we-are-79116">Essays on health: microbes aren't the enemy, they're a big part of who we are</a>
</strong>
</em>
</p>
<hr>
<p>Against this backdrop, it’s little surprise <a href="https://www.campusreview.com.au/2019/02/monash-exhibits-the-humblest-of-objects/">the school lunchbox</a> has again been targeted as one way to help solve today’s public health challenges. </p>
<h2>The ‘gutification’ of food and diets</h2>
<p>Much of the research on microbiomics is in its early stages. There are gaps in scientific knowledge in this field. Still, the focus on the gut and its relation to human health is changing our understanding of food, health and our bodies.</p>
<p>Food corporations have arguably been among the biggest drivers of the gutification of foods. More and more products are labelled using the language and concepts of “gut health”, “mood food” and “immunity boosting”. Yoghurts for children, for example, are marketed using terms such as “probiotics”, “immune boosting” and “strengthening”. </p>
<p>Manufacturers’ marketing is part of a broader trend of using nutrition science in <a href="https://www.bmj.com/content/371/bmj.m4601">“wellness” industries</a>.</p>
<p>However, some <a href="https://theconversation.com/boosting-your-gut-health-sounds-great-but-this-wellness-trend-is-vague-and-often-misunderstood-155472">researchers are cautious</a> about the specific health claims made by food corporations. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4815753/">Others have raised concerns</a> that the general advice to consume probiotics could harm some individuals, such as those with an overactive immune system.</p>
<p>The Therapeutic Goods Administration does regulate products like, for example, <a href="https://www.tga.gov.au/faecal-microbiota-transplant-products-regulation">fecal microbiota transplants</a>. But food-related claims about gut microbiota and health are under-regulated. These products often fall between the cracks of <a href="https://www.tga.gov.au/community-qa/food-and-medicine-regulation">medicine and food</a> regulation and labelling requirements.</p>
<figure class="align-center ">
<img alt="Illustration of various types of priobiotic food products" src="https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444979/original/file-20220208-22-a3uq5j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Many food products are marketed by highlighting their health-giving ‘probiotic’ qualities.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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Read more:
<a href="https://theconversation.com/boosting-your-gut-health-sounds-great-but-this-wellness-trend-is-vague-and-often-misunderstood-155472">Boosting your ‘gut health’ sounds great. But this wellness trend is vague and often misunderstood</a>
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<h2>Is the ‘immunity-boosting’ lunchbox ethical?</h2>
<p>The concern about these products is not just a matter of scientific evidence. In the race to commercialise such products (as with other new food technologies including <a href="https://www.organicgardener.com.au/blogs/nanomaterials-our-food">nano- and biotechnology</a>), the social and ethical dimensions of this burgeoning industry have been neglected. </p>
<p>Industry sees the process of properly considering such questions as <a href="https://www.bostonglobe.com/opinion/2015/07/31/the-moral-imperative-for-bioethics/JmEkoyzlTAu9oQV76JrK9N/story.html">slowing down innovation</a>. But it’s vital to answer these social and ethical questions to ensure community expectations and standards related to food science and innovation are upheld.</p>
<p>In these times of heightened anxiety about child health at school, gut-healthy products can give parents and carers a greater sense of control over their child’s health. Yet almost all of the conditions or diseases gut-healthy foods purport to address have complex causes located in a myriad of structural factors. Public health researchers call these the social determinants of health. </p>
<p>Obesity, heart disease and depression are all complex conditions. They are shaped by family history, environment, geography, genetics, economics and education. These factors are beyond the responsibility of individuals and can’t simply be solved by more probiotics.</p>
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<img alt="lunchbox full of healthy food" src="https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444981/original/file-20220208-18-1dyn958.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">It might help, but don’t expect a healthy lunchbox to be a cure-all for complex public health problems.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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Read more:
<a href="https://theconversation.com/lets-untangle-the-murky-politics-around-kids-and-food-and-ditch-the-guilt-108328">Let's untangle the murky politics around kids and food (and ditch the guilt)</a>
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<p>A major concern within public health ethics is when individuals are made <a href="http://foodfatnessfitness.com/2017/05/01/lifestyle-thin-sociality-neoliberal-welfare/">responsible for social or structural problems</a>. It’s like blaming an individual for not using an energy-saving light bulb while the <a href="https://www.reuters.com/business/energy/australia-resources-minister-floats-a250-bln-coal-lending-facility-2021-10-07/">government is supporting new coal mines</a>. Similarly, expecting a school lunchbox to protect a child from diseases doesn’t make up for inadequate public health infrastructure.</p>
<p>This situation risks putting the responsibility for managing a global pandemic on individual carers (as well as requiring parents and carers to navigate science claims). It also sends a confusing message to the community about the nature of infectious disease transmission and prevention. In the absence of widespread vaccination, ventilation, masks and social distancing, “boosted” immunity is not going to protect children or the community.</p>
<p>The gut microbiome is an exciting new area of research. It opens up wide-ranging possibilities for individual and public health. But uncritical acceptance of health claims that over-promise only serves business interests and risks undermining the integrity of the science and overburdening individuals. </p>
<p>As this field develops, the ethical and social dimensions of human-gut microbiome research cannot be left behind.</p><img src="https://counter.theconversation.com/content/176251/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kristen Lyons is a member of the Australian Greens, and senior research fellow with the Oakland Institute. </span></em></p><p class="fine-print"><em><span>Christopher Mayes and Deana Leahy do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Many school lunchbox products are now heavily marketed as promoting gut health. The limited regulation of such claims leaves it to parents and carers to assess whether they really stack up.Christopher Mayes, Senior Research Fellow, Alfred Deakin Institute, Deakin UniversityDeana Leahy, Associate Professor, Faculty of Education, Monash UniversityKristen Lyons, Professor, Environment and Development Sociology, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1754702022-01-27T14:43:34Z2022-01-27T14:43:34ZProbiotics regulate our immune system and could help fight off COVID – new research<figure><img src="https://images.theconversation.com/files/442963/original/file-20220127-18-1n174g5.jpg?ixlib=rb-1.1.0&rect=152%2C318%2C2649%2C1513&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kuala-lumpur-malaysia-july-10-2016-451899091">Jasni/Shutterstock</a></span></figcaption></figure><p>You’ve probably heard of probiotics – the “<a href="https://www.bbcgoodfood.com/howto/guide/what-are-probiotics-and-what-do-they-do">good bacteria</a>” that can <a href="https://www.nature.com/articles/nrgastro.2014.66">benefit our health</a>. We consume them in an expanding variety of ways, often in foods marketed as being healthy. These bacteria can be contained in supplement capsules, yogurts, drinks or even snack bars. </p>
<p>They work by helping prevent other, disease-causing bacteria from <a href="https://doi.org/10.1111/j.1365-2672.2006.02963.x">infecting our gut</a>. They may also interact with our <a href="https://doi.org/10.1159/000496426">gut’s immune cells</a>, helping regulate the cells’ activity in the complex gut environment, which is important for preventing unwanted inflammation that can trigger inflammatory bowel disease. <a href="https://www.nature.com/articles/s41590-019-0451-9">Research</a> has also shown that the effects of probiotics may go beyond the gut, regulating immune responses in the lungs as well.</p>
<p>Right now, our immune systems face the constant threat of having to fight off the coronavirus, with it circulating at <a href="https://coronavirus.jhu.edu/map.html">record levels</a> around the world since the emergence of the highly infectious omicron variant. There are limited treatments available for people that get seriously ill, and current vaccines <a href="https://news.harvard.edu/gazette/story/2022/01/no-omicron-immunity-without-booster-study-finds/">aren’t highly effective</a> at preventing infection in people that haven’t recently taken a booster. </p>
<p>But if probiotics positively affect our immune system, and their effects are not limited to the gut, could they offer a cheap and accessible way of helping our bodies fight off COVID?</p>
<h2>Bacteria lead to quicker recovery</h2>
<p><a href="https://doi.org/10.1080/19490976.2021.2018899">A recent trial</a> conducted in Mexico showed that people with the coronavirus who took a specific combination of four <a href="https://doi.org/10.1007/s12602-017-9264-z">probiotic bacterial strains</a> recovered quicker compared to those who took a placebo. Those given probiotics also had increased antibody responses to the virus that peaked earlier than the placebo group’s.</p>
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<img alt="Probiotic bacteria in the gut" src="https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442964/original/file-20220127-8283-oqvy00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Though they are delivered to the gut, probiotic bacteria can exert an influence across the body.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/intestinal-bacteria-gut-flora-health-3d-1371437702">nobeastsofierce/Shutterstock</a></span>
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<p>Importantly, those taking the probiotics had lesser symptoms and lower amounts of the virus in their bodies 15 days after their initial infection compared to people taking the placebo. </p>
<p>These encouraging results are some of the first to show that probiotics could help our immune system fight off COVID. The authors suggest that probiotic supplementation could help people recover quicker. This could reduce the self-isolation periods currently imposed on infected people in numerous countries throughout the world.</p>
<p>That said, we need to be careful interpreting these results. Despite being a <a href="https://www.cancer.gov/publications/dictionaries/cancer-terms/def/double-blind-study">double-blind</a>, placebo-controlled clinical trial (generally regarded as the gold standard for testing medical treatments), it had some limitations. It excluded those over the age of 60 and didn’t account for vaccination status of the trial participants. This means we don’t yet know if probiotics provide any benefit to those who are most at risk of developing severe COVID.</p>
<p>In addition, taking probiotics may be inappropriate for those with a weakened immune system. This is due to a potential <a href="https://www.nature.com/articles/s41591-019-0439-x">increased risk of infection</a> resulting from consuming large quantities of live bacteria. </p>
<h2>An axis of immunity</h2>
<p>Research has uncovered a potential positive effect – but can we explain why this happens? How is it that bacteria that arrive in our gut end up helping the immune response against COVID up in the lungs?</p>
<p>Immunologists think they have an answer. They’ve proposed the idea of a <a href="https://doi.org/10.1038/s41385-019-0160-6">gut-lung immune axis</a>. The theory is that immune cells exposed to probiotics in the gut could be activated by these bacteria and then travel to the lung upon infection. In COVID, these would be <a href="https://theconversation.com/coronavirus-b-cells-and-t-cells-explained-141888">B cells</a> – the white blood cells that produce antibodies. They could be “primed” in the gut to go on to produce more antibodies when they encounter the virus in the lung or nose.</p>
<p>However, before probiotics can be properly considered for treating COVID, more studies are needed to validate these results. Clinical trials using probiotics to treat disease often produce <a href="https://www.nature.com/articles/s41591-019-0439-x">varying results</a>, as the effects of probiotic bacteria on immune cells may be highly specific to the bacteria used. Trials must also be performed in different groups of people to see what effect the bacteria have, as we know that COVID is more severe in some than others. <a href="http://dx.doi.org/10.1136/bmjopen-2020-042140">Ethnicity</a> has been associated with COVID mortality, for example.</p>
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<img alt="Kimchee, sour cream and other probiotic foods on a table" src="https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442961/original/file-20220127-18-1peovwh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">It’s not time yet to start loading up on probiotic foods to protect against COVID.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/probiotics-food-background-kimchi-beet-sauerkraut-1320880235">Nina Firsova/Shutterstock</a></span>
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<p>Certainly, there’s no direct evidence currently that the probiotic bacterial strains contained in a store-bought probiotic yogurt would have the same effect as the probiotics tested in the Mexican study. It’s also important to remember that not all the probiotic bacteria contained in foods may be live by the time they are consumed, which could affect their potency.</p>
<h2>What to eat now</h2>
<p>While the evidence on probiotics is being gathered, in the meantime another way to look after your gut bacteria is to eat a healthy fibre-rich diet. The latest research shows that those who consume a healthy diet high in fruits and vegetables are <a href="https://gut.bmj.com/lookup/doi/10.1136/gutjnl-2021-325353">less likely</a> to develop severe COVID. A high-fibre diet that stimulates the gut bacteria may even help your immune system to generate a <a href="https://www.frontiersin.org/articles/10.3389/fimmu.2021.765528/full">stronger response</a> to COVID vaccination.</p>
<p>As COVID will likely remain highly prevalent in the world for the foreseeable future, probiotics have the potential to become a useful tool in our fight against the disease. However, before we all run out to our local health food store to stock up, we need to wait for research to confirm what types of probiotic bacteria could help our immune system and who would most benefit from consuming them.</p><img src="https://counter.theconversation.com/content/175470/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Smith receives funding from the UK Medical Research Council, Medimmune (AstraZeneca), Ferring Pharmaceuticals and Imhotex Ltd. He acts as a consultant for Imhotex Ltd and sits on the Medical Research Awards Panel for Crohn's & Colitis UK.</span></em></p><p class="fine-print"><em><span>Paul Gill does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A recent clinical trial shows that taking probiotics can lead to a quicker recovery from a coronavirus infection.Paul Gill, Postdoctoral Fellow in Microbial Diseases, UCLAndrew Smith, Chair in Oral Health Sciences, Eastman Dental Institute, Faculty of Medical Sciences, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1727802021-12-02T14:22:50Z2021-12-02T14:22:50ZSwapping probiotics for antibiotics: how it could be a game changer for chickens, and us<figure><img src="https://images.theconversation.com/files/434375/original/file-20211129-25-2tx0tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Even chickens need strong, healthy gut microbiomes.</span> <span class="attribution"><span class="source">Moonborne/Shutterstock</span></span></figcaption></figure><p>In 1928, microbiologist Alexander Fleming’s discovery of penicillin was <a href="https://www.nobelprize.org/prizes/medicine/1945/fleming/biographical/">hailed as a scientific breakthrough</a>. In the nearly 100 years since then, scientists have discovered numerous other antibiotics that have saved billions of lives.</p>
<p>However, bacteria have become <a href="https://www.cdc.gov/drugresistance/about.html">increasingly resistant</a> to these treatments. There are two reasons for this: the overuse and misuse of antibiotics by humans, and the introduction of <a href="https://www.sciencedirect.com/science/article/pii/S2666517421000110">antibiotics to agriculture</a>.</p>
<p>During 2021’s <a href="https://www.who.int/campaigns/world-antimicrobial-awareness-week/2021">World Antimicrobial Resistance Awareness Week</a>, the World Health Organisation (WHO) repeated a warning it had issued before: antibiotic resistance is rising to dangerously high levels globally. Globally <a href="https://theconversation.com/antibiotic-resistance-is-at-a-crisis-point-government-support-for-academia-and-big-pharma-to-find-new-drugs-could-help-defeat-superbugs-169443">it is estimated</a> that antibiotic-resistant bacteria kill between 700,000 and several million people every year.</p>
<p>Resistance to antibiotics leads to a situation in which previously treatable infections are becoming harder – and sometimes impossible – to treat. Without urgent action, the world is heading for a post-antibiotic era. Common bacterial infections could once again become frequent killers.</p>
<p>One way to address this crisis is to cut back on the unnecessary use of antibiotics. Some countries are doing this by banning the inclusion of antibiotics in animal feed as growth promoters. This is because when humans consume meat or chicken, we ingest not only the antibiotics added to animal feed, but also antibiotic resistant bacteria. </p>
<p>A 2018 <a href="http://apps.who.int/iris/handle/10665/273128">joint report</a> by the WHO, Food and Agriculture organisation and World Organisation for Animal Health found that only 42% of countries have limited their use as growth promoters. Most are in Europe; only a fraction of countries in Africa and the Americas have taken these steps. The agricultural sector desperately needs alternatives to maintain animal health without detrimental consequences to human health.</p>
<p>The term “antibiotic growth promoter” describes the administration of antibiotics at a low, sub therapeutic dose as a preventative measure. It’s not entirely clear why antibiotics influence livestock growth. However, research suggests that they possibly promote growth by depressing the growth of microbes that are toxic or that steal nutrients from the host, leading to increased nutrition utilisation and reducing the energy that must be invested in maintaining immune responses.</p>
<p>One alternative to this is the use of probiotics, rather than antibiotics, in animal feed. I am a microbiologist and have developed a probiotic for chickens. Most probiotics on the market are not developed for a specific host; ours is developed specifically for chickens and contains multiple bacterial strains, which each target different areas of the gut to strive for complete gut protection. </p>
<p><a href="https://link.springer.com/article/10.1007/s12602-020-09640-z">My research</a> shows that the probiotic has numerous beneficial characteristics – both for chickens and the humans who will ultimately eat them. The probiotic decreases the presence of pathogens in the animal’s gut and can be used safely on a daily basis.</p>
<h2>What are probiotics?</h2>
<p>Probiotics are health-promoting bacteria that naturally occur in the intestine of any animal with a gut. They have a mutually beneficial relationship with the host. A large body of research <a href="https://www.longdom.org/open-access/the-use-of-probiotics-in-animal-nutrition-2329-8901-1000132.pdf">has shown</a> that probiotics may <a href="https://www.intechopen.com/chapters/39589">improve animal health and growth performance</a>. They do so by modulating nutrition and digestion, changing the microbial composition in the intestine, and by stimulating the immune system. </p>
<p>Some probiotic strains also produce vitamins and regulate cholesterol blood levels. They also produce antioxidants – substances that protect your cells against free radicals – and regulate energy production.</p>
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Read more:
<a href="https://theconversation.com/antibiotic-resistance-is-at-a-crisis-point-government-support-for-academia-and-big-pharma-to-find-new-drugs-could-help-defeat-superbugs-169443">Antibiotic resistance is at a crisis point – government support for academia and Big Pharma to find new drugs could help defeat superbugs</a>
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<p>A chicken’s intestine, like a human’s, is home to a complex microbial ecosystem, the microbiome. It consists of trillions of microorganisms living in symbiosis with the host. These interactions are important for development, health, nutrition, and digestion. </p>
<p>Changes in the microbiome composition can be disruptive and lead to the emergence of pathogenic (harmful) microorganisms. Probiotics can prevent these disturbances by inhibiting the growth of pathogens and restoring the microbiome composition to a natural state. Probiotics can also prime the immune system to recognise pathogens in the gut.</p>
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Read more:
<a href="https://theconversation.com/probiotics-what-they-are-and-how-you-might-benefit-from-them-121587">Probiotics: What they are and how you might benefit from them</a>
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<img alt="A man in a white lab coat, shorts and boots, poses alongside a small flock of chickens." src="https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=507&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=507&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=507&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=637&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=637&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434374/original/file-20211129-23-1shpsmi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=637&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The author with some of his probiotic testers.</span>
<span class="attribution"><span class="source">Stellenbosch University</span></span>
</figcaption>
</figure>
<p>We developed a probiotic for chickens because they are <a href="https://storymaps.arcgis.com/stories/58ae71f58fd7418294f34c4f841895d8">the most farmed animal</a> in the world. There are <a href="https://storymaps.arcgis.com/stories/58ae71f58fd7418294f34c4f841895d8">about 135 chickens for every cow</a>, and three for every human. </p>
<p>The first step in developing a chicken probiotic was to obtain the guts of 25 free-ranging chickens. Free-range chickens were chosen rather than housing-reared birds because they are exposed to the environment and so acquire a natural gut microbiome. The guts were then mashed into a liquid and plated on several hundred Petri dishes. As you can imagine, the resulting smell made me very unpopular with my colleagues and I had to set up my lab in a separate room.</p>
<p>As soon as bacteria started growing, hundreds of different bacteria were isolated and identified to species level.</p>
<p>The isolates were then screened for various beneficial characteristics. These included ability to survive transit in the gut, ability to colonise the gut, production of enzymes that can assist with digestion, and production of antimicrobial compounds that can inhibit pathogens. After eight months, I identified six beneficial bacterial species. Over the next four years <a href="https://www.nature.com/articles/s41598-017-12866-7">I tested the multi-strain probiotic’s safety</a> and its ability to decrease the presence of pathogens in the gut of chickens. </p>
<p>We found that the multi-strain probiotic was safe, increased bird immune responsiveness, and was able to decrease pathogen levels in the gut.</p>
<h2>Environmentally friendly alternatives</h2>
<p>The resulting probiotic, ProbiGal™, is a water based probiotic additive administered in the animals’ drinking water. ProbiGal™ has been extensively tested in intensive rearing settings. It will be launched in South Africa after regulatory approval has been granted by the Department of Agriculture, Forestry and Fisheries. Thereafter, we plan to launch it in the US and Brazil, two of the world’s <a href="https://www.fao.org/poultry-production-products/production/en/">largest poultry producing countries</a>.</p>
<p>Much more – including an outright global ban of antibiotics in animal feed – remains to be done. But products like these are one step in the right direction: an example of an environmentally friendly alternative that’s good for animals and humans.</p><img src="https://counter.theconversation.com/content/172780/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deon Neveling is a postdoctoral research fellow at the University of Stellenbosch he receives funding from the National Research Foundation and the University Technology Fund. In addition, he is the CEO of Biotikum (Pty) Ltd which develops microbial additives for the agricultural industry to promote sustainable farming.</span></em></p>The probiotic decreases the presence of pathogens in the animal’s gut and can be used safely on a daily basis.Deon Neveling, Postdoctoral researcher, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1633632021-07-19T01:13:10Z2021-07-19T01:13:10ZWhat should you eat after you’ve been on antibiotics? And can probiotics and prebiotics get your gut back to normal?<figure><img src="https://images.theconversation.com/files/411348/original/file-20210715-15-ogr7wi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/probiotic-fermented-food-theme-bowl-greek-1317374771">Shutterstock</a></span></figcaption></figure><p>Antibiotics <a href="https://www.nps.org.au/consumers/antibiotics-explained">treat infections</a> caused by bacteria. But they can also destroy the good bacteria in your gut. For some people, this results in an upset stomach and diarrhoea. </p>
<p>One <a href="https://pubmed.ncbi.nlm.nih.gov/32958481/">UK review of the research</a> looked at changes in gut bacteria after antibiotics commonly prescribed for respiratory and urinary tract infections found that after treatment, the numbers and diversity in bacteria types rapidly declines. </p>
<p>It also found some types of “bad” microorganisms increased while some “good” ones decreased. </p>
<p>For most people, once antibiotic treatment was stopped, the <a href="https://pubmed.ncbi.nlm.nih.gov/32958481/">gut bacteria recover</a> to some degree. But <a href="https://pubmed.ncbi.nlm.nih.gov/31629863/">other studies suggest</a> some antibiotics can have long-lasting effects on the balance of microorganisms.</p>
<p>It’s important to use antibiotics only when needed, and definitely not for viral infections, because antibiotics can’t kill viruses such as the common cold or COVID-19.</p>
<p>So what should you eat after a course of antibiotics? You might have heard of probiotics and prebiotics, but what are they, and what evidence is there to show they’re beneficial?</p>
<h2>Probiotics contain ‘good gut bacteria’</h2>
<p><a href="https://en.wikipedia.org/wiki/Probiotic">Probiotics</a> are foods, typically yoghurts and yoghurt drinks, that contain “good gut bacteria”: live microorganisms that can recolonise the gut or improve your gut health. </p>
<p>To be called a probiotic, they <a href="https://pubmed.ncbi.nlm.nih.gov/26443321/">must be</a> able to resist stomach acid and digestive processes, and then be able adhere to the gut walls and grow, while not causing any issues for the gut wall. They must also be tested for safety and efficacy in controlled trials.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/plain-greek-low-fat-how-to-choose-a-healthy-yoghurt-94295">Plain, Greek, low-fat? How to choose a healthy yoghurt</a>
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</em>
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<p>To be called a probiotic, the dose of microorganisms needs to be sufficient to help restore the “good” bacteria, by elbowing out the “bad bacteria”. </p>
<p>Most yoghurts contain “good bacteria” but not all can survive the acidity of the stomach acid or the bacteria won’t grow in the bowel, so there is no probiotic benefit. </p>
<p>For probiotics to exert these beneficial effects, they not only have to make it to the large bowel, but once there they need the right fuel to help them grow well. That’s where prebiotics come into play – but more on them shortly. </p>
<h2>What does the science say about probiotics?</h2>
<p>Probiotics are widely promoted as being good for your overall health. The science on that <a href="https://pubmed.ncbi.nlm.nih.gov/32498430/">has been mixed</a>, but it does suggest people who are likely to get diarrhoea after antibiotics may benefit from consuming them. </p>
<p>One <a href="https://pubmed.ncbi.nlm.nih.gov/29257353/">review of the evidence</a> found probiotics may be useful for those at high risk of antibiotic-associated diarrhoea, such as the elderly and people in hospital. </p>
<figure class="align-center ">
<img alt="Woman in supermarket looks at the packaging of a yoghurt container." src="https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=481&fit=crop&dpr=1 754w, https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=481&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/411779/original/file-20210718-23-1wkz81t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=481&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Most yoghurts contain good bacteria but can’t survive the acidity of the stomach.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-interested-elderly-woman-shopping-supermarket-1979903105">Shutterstock</a></span>
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<p>The review found side effects were common when taking antibiotics and include taste disturbances, nausea, abdominal cramping, soft stools, fever and flatulence. </p>
<p>But people taking probiotics reported fewer side effects, suggesting they may be helpful in countering some of the side effects. </p>
<h2>So what are prebiotics?</h2>
<p><a href="https://en.wikipedia.org/wiki/Prebiotic_(nutrition)">Prebiotics are compounds that</a> help beneficial gut microorganisms grow and survive. </p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/26443321/">Prebiotic foods</a> contain complex carbohydrates that can’t be digested and dietary fibres that resist digestive processes in the stomach and small intestine. </p>
<p>They pass undigested into the large bowel where they are fermented by the healthy “good” bacteria. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/gut-feeling-how-your-microbiota-affects-your-mood-sleep-and-stress-levels-65107">Gut feeling: how your microbiota affects your mood, sleep and stress levels</a>
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<p>To be called a prebiotic, they need to undergo the processes above, and be shown in clinical trials to <a href="https://pubmed.ncbi.nlm.nih.gov/26443321/">selectively improve</a> the microorganism composition in the gut.</p>
<p>Not all dietary fibres are prebiotic. <a href="https://pubmed.ncbi.nlm.nih.gov/33809763/">Common ones include</a> complex carbohydrates called fructo-oligosaccharides, inulin and resistant starch. </p>
<p>You can find foods at the supermarket with added prebiotics, but non-digestible carbohydrates occur naturally in many everyday foods, <a href="https://www.monash.edu/medicine/ccs/gastroenterology/prebiotic/faq">including</a>:</p>
<ul>
<li><p><strong>grains:</strong> barley, rye bread, rye crackers, pasta, gnocchi, couscous, wheat bran, wheat bread, oats</p></li>
<li><p><strong>legumes:</strong> chickpeas, lentils, red kidney beans, baked beans, soybeans </p></li>
<li><p><strong>vegetables:</strong> artichokes, asparagus, beetroot, chicory, fennel bulb, garlic, green peas, leek, onion, shallots, spring onion, snow peas, sweetcorn, savoy cabbage</p></li>
<li><p><strong>fruit:</strong> nectarines, white peaches, persimmon, tamarillo, watermelon, rambutan, grapefruit, pomegranate, dates, figs</p></li>
<li><p><strong>nuts:</strong> cashews, pistachios.</p></li>
</ul>
<figure class="align-center ">
<img alt="Large bowl of mixed bean salad." src="https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/411780/original/file-20210718-25-1idcnt7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Prebiotics can be found in a range of foods, including legumes.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/five-bean-salad-226518142">Shutterstock</a></span>
</figcaption>
</figure>
<p>Additional sources of resistant starch include under-ripe bananas, cooked and cooled rice, cornflour, cooked and cooled potatoes. </p>
<p>For babies, breast milk is naturally rich in oligosaccharides. </p>
<h2>So who should have them?</h2>
<p>Prebiotic foods are good for everyone, contain a range of nutrients and help promote a healthy bacterial gut environment. </p>
<p>The benefits of <em>probiotics</em> for a range of health conditions are unclear – they’re likely to be small, and depend on what is being taken and the underlying health issues. </p>
<p>But people at high risk of diarrhoea after antibiotics may benefit from consuming probiotic – as well as prebiotic – foods daily. </p>
<p>There is also emerging evidence that <a href="https://pubmed.ncbi.nlm.nih.gov/26443321/">combining specific probiotics and prebiotics</a> can increase the beneficial effects of both. Both the pro- and prebiotics could be added to the one food, termed a “synbiotic”, or they could be from separate sources but eaten together. </p>
<p>When it comes to antibiotics, the bottom line is only take them when prescribed for bacterial infections. Take them according to instructions from the manufacturer, your pharmacist and your doctor.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-what-happens-when-you-hold-in-a-fart-98310">Health Check: what happens when you hold in a fart?</a>
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<img src="https://counter.theconversation.com/content/163363/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She has received research grants from NHMRC, ARC, MRFF, Hunter Medical Research Institute, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation, Rijk Zwaan Australia, WA Dept. Health, Meat and Livestock Australia, and Greater Charitable Foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers, the Sax Institute and the ABC. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and the Heart Foundation evidence reviews on meat and dietary patterns.</span></em></p>Antibiotics can destroy the good bacteria in your gut. But some foods can help get it back to normal.Clare Collins, Laureate Professor in Nutrition and Dietetics, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1456682021-01-22T13:32:56Z2021-01-22T13:32:56ZA healthy microbiome builds a strong immune system that could help defeat COVID-19<figure><img src="https://images.theconversation.com/files/377088/original/file-20210104-23-1x5t54j.jpg?ixlib=rb-1.1.0&rect=97%2C64%2C7092%2C3977&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The microbes living in the gut are key to good health.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/intestinal-microbiome-medical-concept-royalty-free-image/1196631894?adppopup=true">Dr_Microbe/iStock/Getty Images Plus</a></span></figcaption></figure><p>You may not know it, but you have an army of microbes living inside of you that are essential for fighting off threats, including the virus that causes COVID-19.</p>
<p>In the past two decades scientists have learned our bodies are home to more bacterial cells than human ones. This community of bacteria that lives in and on us – called the microbiome – resembles a company, with each microbe species performing specialized jobs but all working to keep us healthy. In the gut, the bacteria balance the immune response against pathogens. These bacteria ensure the immune response is effective but not so violent that it causes collateral damage to the host. </p>
<p>Bacteria in our guts can elicit an effective immune response against viruses that not only infect the gut, such as <a href="http://doi.org/10.3390/v10020096">norovirus</a> <a href="http://doi.org/10.1126/science.1258025">and rotavirus</a>, but also those infecting the lungs, such as <a href="https://doi.org/10.1073/pnas.1019378108">the flu virus</a>. The beneficial gut microbes do this by ordering specialized immune cells to produce potent antiviral proteins that ultimately eliminate <a href="https://doi.org/10.1016/j.cell.2020.04.022">viral infections</a>. And the body of a person lacking these beneficial gut bacteria won’t have as strong an immune response to invading viruses. As a result, infections might go unchecked, taking a toll on health.</p>
<p><a href="https://scholar.google.com/citations?user=4y55zc0AAAAJ&hl=en">I am a microbiologist</a> fascinated by the ways bacteria shape human health. <a href="https://www.umassmed.edu/nutrition/melody-trial-info/">An important focus of my research</a> is figuring out how the beneficial bacteria populating our guts combat disease and infection. <a href="https://doi.org/10.1101/2021.01.05.20249061">My most recent work focuses on the link</a> between a particular microbe and the severity of COVID-19 in patients. My ultimate goal is to figure out how to enhance the gut microbiome with diet to evoke a strong immune response – for not just SARS-CoV-2 but all pathogens. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377078/original/file-20210104-21-gqunkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Good bacteria help the immune system ward off harmful microbes.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/good-bacteria-and-bad-bacteria-royalty-free-illustration/611994628?adppopup=true&uiloc=thumbnail_same_series_adp">chombosan/iStock/Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>How do resident bacteria keep you healthy?</h2>
<p>Our immune defense is part of a complex biological response against harmful pathogens, such as viruses or bacteria. However, because our bodies are inhabited by trillions of mostly beneficial bacteria, virus and fungi, activation of our immune response is tightly regulated to distinguish between harmful and helpful microbes.</p>
<p>Our bacteria are spectacular companions diligently helping prime our immune system defenses to combat infections. A seminal study found that mice treated with antibiotics that eliminate bacteria in the gut exhibited an impaired immune response. These animals had low counts of virus-fighting white blood cells, weak antibody responses and poor production of a protein that is vital for <a href="https://doi.org/10.1073/pnas.1019378108">combating viral infection and modulating the immune response</a>. </p>
<p><a href="https://doi.org/10.1371/journal.pone.0184976">In another study</a>, mice were fed <em>Lactobacillus</em> bacteria, commonly used as probiotic in fermented food. These microbes reduced the severity of influenza infection. The <em>Lactobacillus</em>-treated mice did not lose weight and had only mild lung damage compared with untreated mice. Similarly, others have found that treatment of mice with <em>Lactobacillus</em> protects against different <a href="https://doi.org/10.1038/srep04638">subtypes of</a> <a href="https://doi.org/10.1038/s41598-017-17487-8">influenza</a> <a href="https://doi.org/10.1371/journal.ppat.1008072">virus</a> and human respiratory syncytial virus – the <a href="https://doi.org/10.1038/s41598-019-39602-7">major cause of viral bronchiolitis and pneumonia in children</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377079/original/file-20210104-15-4sj7z4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fermented foods like kimchi, red beets, apple cider vinegar, coconut milk yogurt, cucumber pickles and sauerkraut can help provide beneficial bacteria.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/fermented-food-sampler-royalty-free-image/899304124?adppopup=true">marekuliasz/iStock/Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Chronic disease and microbes</h2>
<p>Patients with chronic illnesses including Type 2 diabetes, obesity and cardiovascular disease exhibit a hyperactive immune system that fails to recognize a harmless stimulus and is linked to an altered gut microbiome.</p>
<p>In these chronic diseases, the gut microbiome lacks bacteria that activate <a href="https://doi.org/10.1126/science.1198469">immune cells</a> that block the response against harmless bacteria in our guts. Such alteration of the gut microbiome is also observed in <a href="https://doi.org/10.1073/pnas.1002601107">babies delivered by cesarean section</a>, individuals consuming a poor <a href="https://doi.org/10.1038/nature12820">diet</a> and the <a href="https://doi.org/10.1038/nature11053">elderly</a>. </p>
<p>In the U.S., 117 million individuals – about half the adult population – <a href="https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/">suffer from Type 2 diabetes, obesity, cardiovascular disease or a combination of them</a>. That suggests that half of American adults carry a faulty microbiome army.</p>
<p>Research in my laboratory focuses on identifying gut bacteria that are critical for creating a balanced immune system, which fights life-threatening bacterial and viral infections, while tolerating the beneficial bacteria in and on us.</p>
<p>Given that diet affects the diversity of bacteria in the gut, <a href="https://www.umassmed.edu/nutrition/melody-trial-info/">my lab studies show how diet can be used</a> as a therapy for chronic diseases. Using different foods, people can shift their gut microbiome to one that boosts a healthy immune response. </p>
<p>A fraction of patients infected with SARS-CoV-2, the virus that causes COVID-19 disease, develop severe complications that require hospitalization in intensive care units. What do many of those patients have in common? <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e2.htm">Old age</a> and chronic diet-related diseases like obesity, Type 2 diabetes and cardiovascular disease. </p>
<p><a href="http://doi.org/10.1016/j.jada.2008.12.019">Black and Latinx people are disproportionately affected by obesity, Type 2 diabetes and cardiovascular disease</a>, all of which are linked to poor nutrition. Thus, it is not a coincidence that <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6933e1.htm">these groups have suffered more deaths from COVID-19</a> compared with whites. This is the case not only in the U.S. but also <a href="https://www.washingtonpost.com/world/europe/blacks-in-britain-are-four-times-as-likely-to-die-of-coronavirus-as-whites-data-show/2020/05/07/2dc76710-9067-11ea-9322-a29e75effc93_story.html">in Britain</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377080/original/file-20210104-19-193c73w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Minority communities continue to bear the brunt of the pandemic.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/alice-gaskins-holds-sign-that-says-this-virus-is-killing-news-photo/1215626113?adppopup=true">Blake Nissen for The Boston Globe via Getty Images</a></span>
</figcaption>
</figure>
<h2>Discovering microbes that predict COVID-19 severity</h2>
<p>The COVID-19 pandemic has inspired me to shift my research and explore the role of the gut microbiome in the overly aggressive immune response against SARS-CoV-2 infection. </p>
<p>My colleagues and I have hypothesized that critically ill SARS-CoV-2 patients with conditions like obesity, Type 2 diabetes and cardiovascular disease exhibit an altered gut microbiome that aggravates <a href="https://theconversation.com/exercise-may-help-reduce-risk-of-deadly-covid-19-complication-ards-136922">acute respiratory distress syndrome</a>. </p>
<p>Acute respiratory distress syndrome, a life-threatening lung injury, in SARS-CoV-2 patients is thought to develop from a <a href="http://doi.org/10.1016/j.cytogfr.2020.05.003">fatal overreaction of the immune response</a> called a <a href="https://theconversation.com/blocking-the-deadly-cytokine-storm-is-a-vital-weapon-for-treating-covid-19-137690">cytokine storm</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2">that causes an uncontrolled flood</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2">of immune cells into the lungs</a>. In these patients, their own uncontrolled inflammatory immune response, rather than the virus itself, causes the <a href="http://doi.org/10.1007/s00134-020-05991-x">severe lung injury and multiorgan failures</a> that lead to death. </p>
<p>Several studies <a href="https://doi.org/10.1016/j.trsl.2020.08.004">described in one recent review</a> have identified an altered gut microbiome in patients with COVID-19. And some companies including Seres Therapeutics, 4d Pharma PLC, Evelo Biosciences, VEDANTA bioscience, and Finch Therapeutics have recently attracted investor attention for their work on therapies for diseases including cancer, depression and inflammatory bowel diseases.</p>
<p>Identification of specific bacteria within the microbiome that could predict COVID-19 severity is lacking. </p>
<p>To address this question, my colleagues and I recruited COVID-19 hospitalized patients with severe and moderate symptoms. We collected stool and saliva samples to determine whether bacteria within the gut and oral microbiome could predict COVID-19 severity. The identification of microbiome markers that can predict the clinical outcomes of COVID-19 disease is key to help prioritize patients needing urgent treatment. </p>
<p><a href="https://doi.org/10.1101/2021.01.05.20249061">We demonstrated</a>, in a paper which has not yet been peer reviewed, that the composition of the gut microbiome is the strongest predictor of COVID-19 severity compared to patient’s clinical characteristics commonly used to do so. Specifically, we identified that the presence of a bacterium in the stool – called <em>Enterococcus faecalis</em>– was a robust predictor of COVID-19 severity. Not surprisingly, <em>Enterococcus faecalis</em> has been associated with <a href="https://doi.org/10.1053/j.gastro.2011.05.035">chronic</a> <a href="https://doi.org/10.1016/S0002-9440(10)61172-8">inflammation</a>. </p>
<p><em>Enterococcus faecalis</em> collected from feces can be grown outside of the body in clinical laboratories. Thus, an <em>E. faecalis</em> test might be a cost-effective, rapid and relatively easy way to identify patients who are likely to require more supportive care and therapeutic interventions to improve their chances of survival.</p>
<p>But it is not yet clear from our research what is the contribution of the altered microbiome in the immune response to SARS-CoV-2 infection. A recent study has shown that <a href="https://doi.org/10.1101/2020.12.11.416180">SARS-CoV-2 infection triggers an imbalance in immune cells</a> called <a href="https://doi.org/10.1111/imr.12170">T regulatory cells that are critical to immune balance</a>.</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p>
<p>Bacteria from the gut microbiome are responsible for the <a href="https://doi.org/10.7554/eLife.30916.001">proper activation</a> <a href="https://doi.org/10.1126/science.1198469">of those T-regulatory</a> <a href="https://doi.org/10.1038/nri.2016.36">cells</a>. Thus, researchers like me need to take repeated patient stool, saliva and blood samples over a longer time frame to learn how the altered microbiome observed in COVID-19 patients can modulate COVID-19 disease severity, perhaps by altering the development of the T-regulatory cells. </p>
<p>As a Latina scientist investigating interactions between diet, microbiome and immunity, I must stress the importance of better policies to improve access to healthy foods, which lead to a healthier microbiome. It is also important to design culturally sensitive dietary interventions for Black and Latinx communities. While a good-quality diet might not prevent SARS-CoV-2 infection, it can treat the underlying conditions related to its severity.</p><img src="https://counter.theconversation.com/content/145668/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ana Maldonado-Contreras receives funding from The Helmsley Charitable Trust and her work has been supported by the American Gastroenterological Association. She received The Charles A. King Trust Postdoctoral Research Fellowship. She is also member of the Diversity Committee of the American Gastroenterological Association.</span></em></p>The microbes in your gut influence how your immune system reacts to bacteria and viruses. A severe immune reaction is deadly; a small one lets the virus win. The right balance may depend on your diet.Ana Maldonado-Contreras, Assistant Professor of Microbiology and Physiological Systems, UMass Chan Medical SchoolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1386402020-09-03T14:48:26Z2020-09-03T14:48:26ZWhy low and alcohol free beers could be considered health drinks<figure><img src="https://images.theconversation.com/files/355848/original/file-20200901-14-1dwem69.jpg?ixlib=rb-1.1.0&rect=0%2C36%2C4893%2C3220&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Refreshing in the scientific-medical sense, not just the pints-after-work sense.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/people-men-leisure-friendship-celebration-concept-464199170">Syda Productions/Shutterstock</a></span></figcaption></figure><p>It is often said that weak beer was drunk in preference to dirty water in European towns during the middle ages. This fact is <a href="https://onlinelibrary.wiley.com/doi/10.1002/9783527623488.ch1">probably overstated</a>, but the idea that beer was nutritionally important in the medieval period seems more likely. Weaker, so-called “small beers” would have been low in alcohol but a <a href="https://www.upenn.edu/pennpress/book/14037.html">valuable source of energy and nutrients</a>, helping medieval labourers meet their high energy requirements of 3,000 calories a day. </p>
<p>The industrialisation of brewing led to higher alcohol levels in modern beers, which together with their energy and carbohydrate content means beer is now associated with <a href="https://www.sheffield.ac.uk/polopoly_fs/1.538671!/file/Drinking_Guidelines_Final_Report_Published.pdf">poor health and disease</a>. Growing concerns about the health effects of excessive beer consumption has driven increased interest in no-alcohol and low-alcohol (<a href="https://www.theguardian.com/business/2020/jan/20/uk-brewers-invest-in-low-alcohol-drinks-trend">“nolo”</a>) beers, especially in adults under 30. The acceptability of these beers has increased recently, in part due to brewing developments that require less heat and so retain more of the original flavours.</p>
<p>Research shows that moderate beer intake, as with wine, is associated with a reduced risks of <a href="https://www.ncbi.nlm.nih.gov/pubmed/30166641">heart disease</a>. So it’s plausible that nolo beers could also offer these health and nutritional benefits, but without the negative effects linked to the alcohol and calorie content.</p>
<p>In a <a href="https://www.mdpi.com/2306-5710/6/2/25">recent review</a>, we set out to determine the health benefits of nolo beers and whether they could find a place as nutritious drinks with everyday uses, rather than being drunk typically only by teetotallers and designated drivers. Antioxidants and gut health are areas about which there is considerable interest among the health-conscious and among food producers, and nolo beers can provide for both. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C2764%2C1711&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=373&fit=crop&dpr=1 600w, https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=373&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=373&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/346627/original/file-20200709-62-1h8us8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Alcohol-free beer: like a sports drink, but tastes better.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pleia2/30252646627">Elizabeth K. Joseph</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Probiotics</h2>
<p>Many people think <a href="https://theconversation.com/the-science-behind-probiotics-and-choosing-one-that-works-132804">probiotics</a> are the bacteria in yoghurts and perhaps kombucha, but beer can be probiotic too – that is, it contains live, beneficial bacteria – due to its yeast. A number of yeasts such as <em>Saccharomyces boulardii</em> have been found to play a role in managing <a href="https://journals.sagepub.com/doi/10.1177/1756283X11428502">gastrointestinal disorders</a>, and although this type of beer is yet to be tested to see if it improves gut health, a number of studies are <a href="https://link.springer.com/article/10.1007/s12602-020-09680-5">in the pipeline</a>. A beer using alternative yeasts such as this also could reduce the beer’s sugar content, or through slow fermentation, produce less alcohol. </p>
<p>Other styles of beer such as sour beers and lambics use bacteria similar to those you would find in live yoghurt. But, as with yoghurts, it may not be possible to get an approved health claim, and many products are treated to extend shelf life and in doing so reduce or remove any potential probiotic microorganisms. To contain any live probiotics linked to maintaining a healthy gut and immune system, the beer needs to be fresh, not pasteurised and unfiltered. But this would reduce its shelf-life and risk the production of “off” flavours. </p>
<h2>Polyphenols</h2>
<p>Polyphenols are a large group of compounds found in hops and grains that have been linked to a reduced risk of disease. They have been shown in laboratory tests to be powerful antioxidants, which can mop up dangerous free radicals in the body’s cells, which if left unchecked can increase the risk of diseases, such as heart disease and cancer. While there is doubt about whether this is the <a href="https://ifst.onlinelibrary.wiley.com/doi/10.1111/ijfs.14135">mechanism</a> by which antioxidants keep us healthy, what is clear is that diets rich in a variety of these compounds are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115785/">a good thing</a>.</p>
<p>Beer and nolo beer are rich in polyphenols due to the barley and hops, which means beer can contain <a href="http://europepmc.org/article/med/25442616">over 50 different compounds</a> that could provide benefits from affecting gastrointestinal health to controlling bacteria growth. Beers containing more hops, such as IPAs, tend to contain even more of these <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12352">potential health-promoting polyphenols</a> than lagers.</p>
<p>There is now recognition that nolo beers can potentially be marketed as health products. German brewer Erdinger’s <a href="https://int.erdinger.de/beer/alkoholfrei.html">alcohol-free wheat beer</a> contains electrolytes that can aid the absorption of water to help digestion – something often referred to as “isotonic” when found in a sports drink. The beer is also a source of folate and vitamin B12 due to the action of the yeast in the bottled beer (particularly important for vegans, for whom there are few natural sources of vitamin B12 available). </p>
<p>Erdinger market this beer as “isotonic” and “a sporty thirst quencher”, which suggests it has identified that the beer is both suitable for, and is of interest to, groups beyond those wishing to avoid alcohol. The sports drink potential of nolo beers has been tested in the lab too, with low alcohol beers being <a href="https://www.frontiersin.org/articles/10.3389/fnut.2016.00045/full">almost as good</a> as sports drinks for rehydrating, especially if a <a href="https://journals.humankinetics.com/view/journals/ijsnem/23/6/article-p593.xml">pinch of salt</a> is added. </p>
<p>While nolo beers are <a href="https://www.theguardian.com/business/2020/jan/20/uk-brewers-invest-in-low-alcohol-drinks-trend">growing in popularity</a>, it may be that traditional beer fans may struggle to accept them as “real ales”, given the poor reputation of low-alcohol beers in the past. But with improving brewing and alcohol-removal methods, the flavour and potentially the health benefits of low alcohol beers can be retained, while reducing the negatives of excess alcohol and calories. Even the most ardent beer fans may yet be won over.</p><img src="https://counter.theconversation.com/content/138640/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ray Carson is a Director of Beertorrent Ltd. </span></em></p><p class="fine-print"><em><span>Bishoy Hanna-Khalil and Duane Mellor do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Remove the alcohol and calories, and it turns out beer is a drink that has many qualities found in health drinks.Duane Mellor, Senior Teaching Fellow, Aston Medical School, Aston UniversityBishoy Hanna-Khalil, Clinical Teaching Fellow, Aston UniversityRay Carson, Senior Lecturer and Medical Studies Co-ordinator, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1390942020-06-21T05:34:02Z2020-06-21T05:34:02ZGut reaction: How the gut microbiome may influence the severity of COVID-19<figure><img src="https://images.theconversation.com/files/340491/original/file-20200609-165357-rmp03n.jpg?ixlib=rb-1.1.0&rect=41%2C83%2C6769%2C5396&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The gut microbiome is the community of micro-organisms living inside the gastrointestinal tract, which performs many beneficial functions, including educating the immune system. </span> <span class="attribution"><span class="source">(Shutterstock))</span></span></figcaption></figure><p>The risk of severe COVID-19 infection is more common in those with high blood pressure, diabetes and obesity, conditions that are all associated with <a href="https://dx.doi.org/10.3390%2Fmedsci6020032">changes to the composition of the gut microbiome — the community of bacteria, viruses and fungi that live in the intestines</a>. This raises the question of whether the gut microbiome has a role in dictating COVID-19 severity.</p>
<p>Let’s recap what we know about COVID-19. <a href="https://doi.org/10.1038/s41586-020-2012-7">COVID-19 is a new disease</a> caused by a very contagious virus called SARS-CoV-2. </p>
<p>In <a href="https://www.canada.ca/content/dam/phac-aspc/documents/services/publications/diseases-conditions/coronavirus/covid-19-know-the-facts/04-03-02-COVID-Know-The-Facts-EN-04.pdf">most infected individuals</a>, the virus does not cause serious illness. However, it causes a very serious respiratory disease — and even death — in a minority of patients. Through many studies of people with COVID-19 over the past few months, we have learned what <a href="https://www.the-scientist.com/news-opinion/why-some-covid-19-cases-are-worse-than-others-67160">characteristics are more likely to be linked</a> to mild versus severe forms of the disease. </p>
<h2>Who is predisposed to serious COVID-19?</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/341313/original/file-20200611-80789-1ez8z5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Coronavirus causes respiratory infections.</span>
<span class="attribution"><span class="source">(Piqsels)</span></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1542/peds.2020-0702">Children</a> and <a href="https://doi.org/10.1016/j.jmii.2020.05.001">young adults</a> are less likely to develop symptomatic COVID-19, although <a href="https://doi.org/10.1056/NEJMc2005073">infection readily occurs in young people</a> with equally <a href="https://doi.org/10.1093/cid/ciaa201">high viral loads</a> in the airway, suggesting that they can certainly infect others. In contrast, people of older age and those with <a href="https://doi.org/10.1016/j.ijid.2020.03.017">pre-existing chronic conditions</a> are highly at risk and very likely develop symptomatic, severe disease. </p>
<p>If we consider the gradient of severity of the disease, children are at one end, and the elderly and patients with chronic conditions are at the other end. </p>
<h2>What conditions are linked to severe COVID-19?</h2>
<p>The information collected by researchers from many countries all points to similar characteristics and health conditions that are more commonly seen in patients with severe disease. These include older age, high blood pressure, diabetes and <a href="https://doi.org/10.1016/S2213-8587(20)30160-1">obesity</a>. </p>
<p>The strength of these associations is even more prominent among younger individuals, as younger patients with <a href="https://doi.org/10.1016/S0140-6736(20)31024-2">obesity</a> and <a href="https://doi.org/10.1016/j.dsx.2020.04.018">diabetes</a> are more likely to have serious disease. </p>
<p>In <a href="http://dx.doi.org/10.1136/bmj.m1966">New York City</a>, 5,279 patients tested positive for COVID-19 between March 1 and April 8, 2020. Of these, 22.6 per cent had diabetes and 35.3 per cent were obese. </p>
<p>Obesity was associated with an increased rate of hospital admission and critical illness. Similar findings were provided by <a href="https://doi.org/10.1101/2020.05.06.20092957">investigators in the United Kingdom</a> about the outbreak in Britain, where obese patients were twice as likely to develop severe disease.</p>
<p>Do these findings raise the possibility that the mechanisms underlying high blood pressure, diabetes and obesity may help explain why these conditions lead to severe COVID-19 disease? Before exploring this question, let’s zoom in on cellular and molecular mechanisms known to be involved in COVID-19 disease.</p>
<h2>How does the body fight COVID-19 infection?</h2>
<p>When the virus enters the body, it mostly goes to the <a href="https://doi.org/10.1038/s41591-020-0868-6">airways</a> and the <a href="https://www.doi.org/10.1126/science.abc1669">gastrointestinal tract</a>. The virus then binds to <a href="https://doi.org/10.1016/j.cell.2020.02.052">specific receptors present</a> on the surface of epithelial cells to enter these cells. Viral replication within the cells leads to cell damage and cell death. This results in the release of specific signalling molecules that alert the local <a href="https://doi.org/10.1038/s41418-020-0530-3">immune system</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/341349/original/file-20200611-80774-4u8yi6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Illustration of the initial stage of COVID-19 infection: SARS-CoV-2 virus particles binding to specific receptors on the surface of cells.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Armies of immune cells are then dispatched to initiate an antiviral response. Some of these cells are specialized to locate and identify the virus, while others mount a specific immune attack. The <a href="https://doi.org/10.1038/s41577-020-0311-8">immune response</a> results in the release of cytokines, chemokines and antibodies, which in many cases can defeat the virus, and the patient recovers. </p>
<p>Sometimes the immune system is dangerously at high alert and overreacts. In this case, the immune cells mount an especially strong inflammatory response — one that goes beyond what is required to kill the virus. This extra-strong attack releases cytokines and chemokines on a massive scale throughout the body, resulting in a <a href="https://doi.org/10.1016/j.cytogfr.2020.05.003">cytokine storm</a>, which causes widespread inflammation and tissue damage in patients with severe COVID-19. </p>
<p>One of the reasons for an abnormal, overreactive immune response lies in the gastrointestinal tract. Millions of interactions are constantly occurring between the immune system and trillions of non-dangerous microbes that live within the body. These interactions educate the immune system in how to function and, importantly, in how not to overreact to infectious microbes. Could this help explain why some people are more likely to develop uncontrolled inflammation upon COVID-19 infection?</p>
<h2>Trillions of micro-organisms that call your gastrointestinal tract home</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=777&fit=crop&dpr=1 600w, https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=777&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=777&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=977&fit=crop&dpr=1 754w, https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=977&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/341316/original/file-20200611-80758-lnvb8u.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=977&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">You’ve got a trillion friends in low places: bacteria in the gut may protect against viruses by signalling their presence to the immune system.</span>
<span class="attribution"><span class="source">(Piqsels)</span></span>
</figcaption>
</figure>
<p>The gut microbiome is the community of micro-organisms living inside the gastrointestinal tract, mostly in the large bowel. The microbiome contains bacteria, fungi (yeast), viruses and protozoa, all of which contribute to maintaining a balanced ecosystem and human health. These microbes collectively perform many beneficial functions, including educating the immune system. </p>
<p>When studying the microbiome, scientists examine the composition (what is there) and function (what are they doing) of this ecosystem. We have learned that both composition and function of the gut microbiome are important <a href="https://doi.org/10.1016/J.ENG.2017.01.008">features linked to human health</a>. In certain conditions, the balance of the gut microbiome composition and function is disrupted in a way that leads to disease, a phenomenon called microbiome dysbiosis. </p>
<p>There is accumulating evidence from animal and human studies that <a href="https://doi.org/10.1016/j.molcel.2020.03.005">gut microbiome dysbiosis has a causal role</a> in metabolism dysregulation manifested as diabetes and obesity — the risk factors of severe COVID-19 disease. </p>
<h2>Is gut microbiome predisposing patients to severe COVID-19?</h2>
<p>The gut microbiome regulates host defences against viral infections including respiratory viruses, such as <a href="https://doi.org/10.1073/pnas.1019378108">influenza virus</a>. This occurs through the activation of immune antiviral mechanisms and the prevention of excessive inflammation. </p>
<p>Different species of the gut microbiome have pro- or anti-inflammatory properties and play different roles in regulating the immune system. In the context of COVID-19, <a href="https://doi.org/10.1101/2020.04.22.20076091">a recent preprint study (not yet peer reviewed)</a> showed that specific members of the gut microbiome were associated with severe disease and with immune markers known to be elevated in severe disease. The association of these gut bacteria with the immune markers was even higher than that of the known risk factors of COVID-19 severity: age and obesity.</p>
<p>Further work is needed to confirm that pro-inflammatory microbial species can contribute to the immune responses that make severe COVID-19 more likely, but based on what we know about the microbiome, this is certainly a possibility. This also could mean that beneficial gut microbiome species, the type that promote low inflammation, have the potential to prevent or remediate the immune alterations that lead to severe COVID-19.</p>
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<h2>Potential for treatments and prevention</h2>
<p>The research community is working very hard to develop and test <a href="https://doi.org/10.1016/j.immuni.2020.03.007">safe and effective vaccines</a> and treatments against COVID-19. Tapping into the potential of the gut microbiome is another avenue that we can pursue to identify potential <a href="https://doi.org/10.1038/s41564-020-0721-1">safe and affordable probiotics</a> for prevention and treatment. This is not unprecedented in the context of viral respiratory diseases: probiotics and prebiotics can affect the immune response to the <a href="https://doi.org/10.3390/nu9111175">flu vaccine</a>, and may improve outcomes in <a href="https://doi.org/10.3389/fphar.2019.00980">flu-like illnesses</a>. </p>
<p>Until effective treatments are available, “mind your microbes” and maintain a healthy lifestyle.</p><img src="https://counter.theconversation.com/content/139094/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shirin Moossavi receives funding from Canadian Institute of Health Research.</span></em></p><p class="fine-print"><em><span>Marie-Claire Arrieta receives funding from the Cumming School of Medicine, the Alberta Children Hospital Research Institute, the Snyder Institute of Chronic Diseases, the Canadian Institutes for Health Research, the Sick Kids Foundation, the W. Garfield Weston Foundation, and the Canadian Lung Association. She is affiliated with the University of Calgary. </span></em></p>The disease is more severe in people with obesity, diabetes and hypertension — all conditions linked to changes in the gut microbiome.Shirin Moossavi, Postdoctoral Fellow, International Microbiome Centre, University of CalgaryMarie-Claire Arrieta, Assistant Professor, Physiology, Pharmacology and Pediatrics, University of CalgaryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1341582020-03-19T14:01:08Z2020-03-19T14:01:08ZCoronavirus: how to keep your gut microbiome healthy to fight COVID-19<figure><img src="https://images.theconversation.com/files/321546/original/file-20200319-22632-172imum.jpg?ixlib=rb-1.1.0&rect=8%2C34%2C5742%2C3794&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A Mediterranean diet is good for your gut health.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/caprese-italian-mediterranean-salad-tomato-mozzarella-291753935">Marian Weyo/Shutterstock</a></span></figcaption></figure><p>These are unprecedented times. COVID-19 (the illness caused by the new coronavirus SARS-CoV-2) has <a href="https://www.nytimes.com/2020/03/11/health/coronavirus-pandemic-who.html">officially been declared a pandemic by the World Health Organization</a>. Many countries have sealed their borders and put the population under voluntary or enforced lockdown. Cultural and sporting events have been cancelled or postponed – including <a href="https://www.bbc.co.uk/sport/football/51909518">Euro 2020</a> and the <a href="https://www.bbc.co.uk/news/entertainment-arts-51942898">Glastonbury festival</a> – pubs and restaurants are closing, and people are <a href="https://www.bbc.co.uk/news/business-51941987">panic buying staples such as toilet paper and pasta</a>. But although it can feel like the situation is out of control, there are still plenty of things you can do to protect your health and that of the people around you.</p>
<p>First and foremost, follow national <a href="https://www.nhs.uk/conditions/coronavirus-covid-19/">guidance for preventing COVID-19</a>: avoid spreading the virus and cut your chances of catching it by regularly washing your hands, avoiding touching your face and reducing social contact. This is particularly important for protecting at-risk groups including people with existing health conditions, the elderly and pregnant women.</p>
<p>As well as protecting yourself from the virus on the outside, you can also build up your defences from the inside by strengthening your immune system. Many people, especially the young, develop only very mild disease. The immune system is complex and highly responsive to the world around us, so it’s not surprising that many factors affect its function. What’s important to know is that most of these factors are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4302727/">not hard-coded in our genes</a> but are influenced by lifestyle and the world around us.</p>
<p>One thing that you can control immediately is the health of the trillions of microbes living in your gut, collectively known as the microbiome. Recent research has shown that the gut microbiome plays an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104162/">essential role in the body’s immune response to infection</a> and in maintaining overall health. As well as mounting a response to infectious pathogens like coronavirus, a healthy gut microbiome also helps to prevent potentially dangerous immune over-reactions <a href="https://www.nytimes.com/interactive/2020/03/11/science/how-coronavirus-hijacks-your-cells.html">that damage the lungs and other vital organs</a>. These excessive immune responses can cause respiratory failure and death. (This is also why we should talk about “supporting” rather than “boosting” the immune system, as an overactive immune response can be as risky as an underactive one.)</p>
<h2>Healthy microbiome, healthy gut, healthy body</h2>
<p>Rather than taking supplements that claim to “boost your immune system” with no good supporting evidence, the food you eat has a big impact on the range and type of microbes in the gut. A <a href="https://joinzoe.com/2019/07/23/improve-microbiome-diversity-gut-health">diverse microbiome is a healthy microbiome</a>, containing many different species that each play their part in immunity and health. Microbiome diversity <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1007727">declines as you get older</a>, which may help to explain some of the age-related changes we see in immune responses, so it’s even more necessary to maintain a healthy microbiome throughout life.</p>
<p>The fine details of the interactions between the gut microbiome and the immune system are not fully understood. But there seems to be a link between the <a href="https://www.nature.com/articles/s41467-019-12873-4">makeup of the microbiome and inflammation</a> – one of the hallmarks of the immune response. Gut bacteria produce many beneficial chemicals and also <a href="https://www.sciencedaily.com/releases/2018/12/181218123123.htm">activate vitamin A</a> in food, which helps to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162863/">regulate the immune system</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321548/original/file-20200319-22598-66ss73.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Gut bacteria produce many beneficial chemicals.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/bacteria-lactobacillus-3d-illustration-normal-flora-1104385652">Kateryna Kon/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Eat to feed your microbiome</h2>
<p>The best way to increase microbiome diversity is by <a href="https://joinzoe.com/2019/08/20/how-to-eat-more-plants">eating a wide range of plant-based foods</a>, which are high in fibre, and limiting <a href="https://www.smh.com.au/national/boosting-immunity-can-help-your-body-battle-coronavirus-20200312-p549gc.html">ultra-processed</a> foods including junk food. Following a Mediterranean diet has also been shown to <a href="https://gut.bmj.com/content/early/2020/01/31/gutjnl-2019-319654">improve gut microbiome diversity and reduce inflammation</a>: eating plenty of fruit, vegetables, nuts, seeds and whole grains; healthy fats like high-quality extra virgin olive oil; and lean meat or fish. Avoid alcohol, salt, sweets and sugary drinks, and artificial sweeteners or other additives.</p>
<p>If you are concerned about getting hold of fresh produce while self-isolating or quarantined, frozen fruit, berries and vegetables are <a href="https://www.insider.com/which-is-better-fresh-vs-frozen-vegetables-2018-6">just as healthy as their fresh counterparts</a> and will last much longer than the currently recommended two-week isolation period. Canned fruit, beans and pulses are another long-lasting option.</p>
<p>You can also support your microbiome by regularly eating natural yoghurt and artisan cheeses, which contain live microbes (<a href="https://theconversation.com/the-science-behind-probiotics-and-choosing-one-that-works-132804">probiotics</a>). Another source of natural probiotics are bacteria and yeast-rich drinks like kefir (fermented milk) or kombucha (fermented tea). Fermented vegetable-based foods, such as Korean kimchi (and German sauerkraut) are another good option.</p>
<p>Whether you’re shopping for yourself, your family or for elderly relatives or friends, choosing foods that support a healthy gut microbiome is much more important than stockpiling toilet paper. <a href="https://www.oxfordhealth.nhs.uk/news/coronavirus-and-your-mental-wellbeing/">Managing your mental health</a>, staying physically active and getting enough sleep will also help to keep your immune system in good shape. And don’t forget to wash your hands!</p>
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<img alt="" src="https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=140&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=140&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315932/original/file-20200218-11040-p9wweg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=140&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>To find out more about the importance of the gut microbiome, listen to Medicine made for you, a series by The Anthill podcast on the future of healthcare and how it could soon get a lot more personal. <a href="https://theconversation.com/how-personal-will-nutritional-advice-become-in-the-future-medicine-made-for-you-part-2-132387">Listen here</a> or subscribe to The Anthill wherever you get your podcasts.</em></p><img src="https://counter.theconversation.com/content/134158/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tim Spector receives academic grants from many sources including MRC, Wellcome Trust, NIHR, CDRF, Danone, Zoe Global. He is a co-founder of the precision nutrition company Zoe Global LTD.
He receives royalties from two popular science books - The Diet Myth (Orion 2016) and Spoon-Fed (Jonathan Cape 2020) </span></em></p>Your gut plays an important role in building your immune defences. Don’t neglect it.Tim Spector, Professor of Genetic Epidemiology, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1328042020-03-06T15:08:18Z2020-03-06T15:08:18ZThe science behind probiotics – and choosing one that works<figure><img src="https://images.theconversation.com/files/319082/original/file-20200306-118960-12tm78l.jpg?ixlib=rb-1.1.0&rect=0%2C16%2C3680%2C2434&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Choosing the right probiotic strain is also important. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/white-medicine-capsules-pill-bottle-on-1076904332">Vinogradskaya Natalia/ Shutterstock</a></span></figcaption></figure><p>We have trillions of bacteria living on or in us – and over <a href="https://gut.bmj.com/content/67/9/1716">80% of these live in our gut</a>. Over thousands of years of co-evolution, we have developed a way of working together with our bacteria, which play a hugely important role in our bodies. They help us <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5847071/">synthesise vitamins and digest fibre</a>. A growing body of evidence also suggests that they play a vital role in our health and wellbeing, too. </p>
<p>Imbalances in our gut bacteria can cause us to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4425030/">develop chronic diseases</a>, including obesity, type 2 diabetes and inflammatory bowel disease. These imbalances can occur when you <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5725362/">take antibiotics</a>, which can wipe out the healthy bacteria in your gut. It can also happen if you have a poor diet.</p>
<p>Imbalances in gut bacteria can even have an impact on <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641835/">our mental health</a>. And, more neurotransmitters (the chemical signals that send messages between neurons, nerves, and cells) are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772764/">produced in the gut</a> than in the brain. Maintaining the balance and diversity of these organisms in the gut is vital for our wellbeing. </p>
<p>One of the best ways of correcting and maintaining good gut bacteria balance is to consume probiotics. Probiotics are <a href="https://www.nhs.uk/conditions/probiotics/">live microorganisms</a> that are beneficial to our gut health. They occur naturally in <a href="https://www.health.harvard.edu/staying-healthy/how-to-get-more-probiotics">some fermented foods</a>, including yoghurt, sauerkraut and sourdough bread. They can also be taken as a supplement. </p>
<p>Probiotics work by crowding out any <a href="https://www.sciencedirect.com/science/article/pii/S1319016413000819">potentially bad bacteria</a>, taking up space and using up nutrients they would need to reproduce. They also help digest foods that we can’t, such as fibre and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5646248/">resistant starch</a>. They produce lots of beneficial substances along the way, such as short-chain fatty acids that fuel our gut cells, helping to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266989/">build the gut barrier</a> that prevents disease-causing microorganisms from moving to other parts of the body.</p>
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<p><em>Listen to <a href="https://theconversation.com/how-personal-will-nutritional-advice-become-in-the-future-medicine-made-for-you-part-2-132387">Medicine made for you</a>, a series from The Conversation’s Anthill podcast to find out more about the gut and your diet.</em> </p>
<iframe src="https://player.acast.com/5e3bf1111a6e452f6380a7bc/episodes/medicine-made-for-you-part-2-your-diet?theme=default&cover=1&latest=1" frameborder="0" width="100%" height="110px" allow="autoplay"></iframe>
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<p>Probiotics can also produce special antibiotic-like substances that kill harmful bacteria, called <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/bacteriocin">bacteriocins</a>. Probiotics help to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5048567/">prime our immune system</a> so our cells are ready to tackle bacterial and viral invaders. </p>
<p>But to get to the gut, probiotics need to go on a journey through our digestive system, which is filled with acid and bile – so they need to be hardy. They have to survive the journey not only inside us but also during the manufacture of food products or supplements, and in sufficient enough numbers to make a difference to our guts. Probiotics should contain <a href="https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/">one billion to 10 billion</a> viable organisms. And, once they’ve reached the gut, they have to be able to stick to the cells and start breaking down fibre and producing vitamins.</p>
<h2>Choose right</h2>
<p>When it comes to choosing the right probiotic, there are a number of things to consider. First, they have to be safe. Any organism used in probiotic supplements should have <a href="https://www.sciencedirect.com/science/article/abs/pii/S0924224410001536">passed tests that show they are safe to consume</a> from the European Food Safety Authority, or, in the US, be “<a href="https://www.fda.gov/food/food-ingredients-packaging/generally-recognized-safe-gras">generally recognised as safe</a>” organisms – meaning they won’t cause harm when used as intended.</p>
<p>Second, strain is important, as different bacterial strains perform different functions. Species in the <a href="https://www.sciencedirect.com/topics/food-science/lactobacillus">Lactobacillus</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4908950/">Bifidobacterium</a> categories are the most common, but they don’t all do the same thing. <em>Lactobacillus plantarum</em> have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5724841/">potential cholesterol lowering properties</a>, whereas <em>Lactobacillus reuteri</em> are able to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5917019/">inhibit the growth</a> of germs such as <em>E coli</em>.</p>
<p>These “lactic acid” bacteria can generally withstand the low pHs and high temperatures often involved in food processing, but <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6463069/">not in all cases</a>. Some strains of <em>Lactobacillus paracaesi</em> and <em>Lactobacillus fermentum</em> <a href="https://www.sciencedirect.com/science/article/pii/S0740002013002037">cannot survive processing</a>. </p>
<p>In order <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789095">to withstand</a> the harsh conditions of processing and acid in the human gut, bacteria can be freeze dried (<a href="https://www.phe-culturecollections.org.uk/news/nctc-news/lyophilisation-long-term-storage-for-bacterial-strains.aspx">lyophilised</a>), or they may be wrapped in a resistant coating (<a href="https://www.intechopen.com/books/probiotics/encapsulation-technology-to-protect-probiotic-bacteria">encapsulated</a>). <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3223967/">Alginate</a> made from seaweed is frequently used as a coating because it’s low-cost, non-toxic and biodegradable, and can withstand the journey to the gut. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/319083/original/file-20200306-118966-1hoxyjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Most probiotic foods should be kept refrigerated.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/set-fermented-food-great-gut-health-485504767">marekuliasz/ Shutterstock</a></span>
</figcaption>
</figure>
<p>There are a large number of different probiotic supplements and strains available. Since probiotics need to be delivered to the gut to work, they are most commonly and effectively taken orally, usually in a tablet or capsule. These usually <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683253/">don’t need to be refrigerated</a> as the bacteria will return to their active state in the gut. However, these should be kept away from moisture to maintain viability. </p>
<p>Probiotics found in food products, especially liquid or semi-solid ones such as milk or yoghurt, usually need refrigeration to keep them safe. Their effectiveness <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3909163/">can also depend on</a> what other bacteria are in the product, oxygen content and temperature.</p>
<p>So should you be adding probiotics to your diet? If you’re healthy and follow a balanced diet already, the foods you eat <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5385025/">should provide your gut</a> with all the fuel required to maintain a good balance. While additional probiotics can be useful in some situations – such as after finishing a course of antibiotics – they shouldn’t replace a balanced diet rich in fruits, vegetables and fermented foods.</p>
<p>A person’s eating habits are a major factor in maintaining gut balance. The foods we eat can influence both the microbial populations and what these bacteria and microbes do, even from the early stages of life. Maintaining the balance and diversity of organisms in the gut is key for good, overall health.</p><img src="https://counter.theconversation.com/content/132804/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janice Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Probiotics sold in tablets or capsules don’t need to be refrigerated to work.Janice Taylor, Glasgow Caledonian UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1215872020-01-23T17:33:13Z2020-01-23T17:33:13ZProbiotics: What they are and how you might benefit from them<figure><img src="https://images.theconversation.com/files/304349/original/file-20191128-178121-1xivflu.jpg?ixlib=rb-1.1.0&rect=269%2C22%2C4580%2C2971&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Increased scientific understanding of the role microbes play in humans and other animals has led to the development of probiotics to improve heath. </span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Probiotics are <a href="http://www.fao.org/3/a-a0512e.pdf">live microorganisms, usually bacteria, that can be consumed to offer health benefits</a>. </p>
<p>The ability of certain microbes to confer health benefits on their host was recognized more than 100 years ago. In 1904, Elie Metchnikoff, a scientist at the Pasteur Institute, claimed that <a href="https://www.smithsonianmag.com/science-nature/science-lecture-accidentally-sparked-global-craze-yogurt-180958700/">Bulgarian peasants lived longer by eating yogurt made from bacteria that served to ferment the milk</a>. Parisians rushed out to buy yogurt in response.</p>
<p>However, the huge variety of bacteria living on the planet was not appreciated back then. More recently, the development of technology that identifies organisms from their DNA has allowed scientists to show that <a href="https://doi.org/10.1093/femsle/fnz117">plants, animals, insects and humans can be hosts for many different types of microorganisms</a>.</p>
<p>This has fostered <a href="https://www.newscientist.com/round-up/microbiome/">the term “microbiome”</a> as studies have uncovered the <a href="https://doi.org/10.1038/nature06244">range of organisms present throughout the human body and their association with many diseases</a> — from cardiovascular and digestive diseases to anxiety, allergies and infection.</p>
<p>Recognition of the roles that microbes play has led to the purposeful development of <a href="https://www.healthlinkbc.ca/health-topics/tw2302spec">microbes (probiotics)</a> that aim to restore and maintain health in humans and other life forms. </p>
<h2>From babies to honey bees</h2>
<p>One research group discovered that some strains of probiotic lactobacilli can be used instead of antibiotics to <a href="https://doi.org/10.1086/652763">treat women with infectious mastitis</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304351/original/file-20191128-178066-jgyuhm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One research study shows probiotics to be an efficient alternative to antibiotics for the treatment of infectious mastitis during lactation.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The use of probiotics can also be used in other life forms. They can counter the <a href="http://www.dx.doi.org/10.1128/AEM.02820-17">damage pesticides cause to the immune system of insects such as the honey bee</a>. </p>
<p>Research has also shown that gut microbes can affect the drugs we take, <a href="https://doi.org/10.1038/nrmicro.2016.17">processing them to become more active, less active and even toxic</a>. </p>
<h2>Probiotics for urogenital health</h2>
<p>In 1982, Dr. Andrew Bruce, then the chair of urology at Toronto General Hospital, and I decided to try to use lactobacilli to reduce the incidence of urinary and vaginal infections among women. </p>
<p>The idea was based on the finding that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941341">lactobacilli are dominant in the vagina and urethra of healthy women, but <em>E. coli</em> and other pathogens displace them in disease</a>. We theorized that by boosting the lactobacilli in the vagina and perineum (the space between the anus and the vulva), we could reduce the ascent of infective bacteria into the bladder.</p>
<p>The laboratory and clinical research took over 20 years to identify the lactobacilli that could best inhibit and disrupt the harmful bacteria. The end result was a product containing <em>Lactobacillus rhamnosus</em> GR-1 and <em>Lactobacillus reuteri</em> RC-14 that is now sold in more than 30 countries as <a href="https://doi.org/10.1139/cjm-2016-0733">a probiotic to alleviate the suffering associated with these conditions</a>.</p>
<p>With no alternative to antibiotics in almost 50 years, the contribution of probiotics to managing urogenital health is tangible and worthy of further exploration.</p>
<p>Other substances called prebiotics (essentially food for beneficial microbes) can also provide health benefits. For example, inulin from the chicory root, or human oligosaccharides in breast milk, <a href="https://doi.org/10.1038/nrgastro.2017.75">stimulate bacteria in the gut</a>. Compounds like lactulose may <a href="https://doi.org/10.1128/AEM.02200-17">help prevent urogenital infection</a>. </p>
<h2>The success of poop transplants</h2>
<p>If someone has a really disrupted intestinal microbiome, such as when antibiotic use leads to infection by <em>Clostridium difficile</em>, then the solution may be a fecal transplant — transferring a healthy person’s poop into their gastrointestinal tract. </p>
<p>As yucky as it sounds, it has a cure rate of <a href="https://dx.doi.org/10.1155%2F2018%2F1394379">80 to 90 per cent for this infection</a>. It is is done by <a href="https://doi.org/10.1038/ismej.2014.13">inserting a healthy stool (which is mostly microorganisms) into the intestine via the rectum</a> or via a tube from mouth to stomach. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304354/original/file-20191128-178094-oongbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">3D illustration of intestinal bacteria.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The success, and the now recognized link between the gut microbiome and health at other body sites, has led to fecal microbiota transplant being considered to treat other diseases. Examples include multiple sclerosis, digestive and <a href="http://www.dx.doi.org/10.1053/j.gastro.2019.01.033">liver diseases</a>. The rationale is that the transplanted bacteria can produce molecules that affect metabolism and other organ functions. </p>
<h2>Regulation of probiotics</h2>
<p>Probiotics tend to be sold as dietary supplements and foods, which keeps manufacturers from claiming they treat disease, even though some studies have shown efficacy. This dates back to regulators stating that only drugs can cure, treat, prevent and mitigate disease. </p>
<p>While this is an outdated view, it has formed the system within which all health and disease-related products are adjudicated. One result has been to curtail research and development and clinical studies by researchers and companies in the United States and Europe. </p>
<p>Many commercial products have been labelled as probiotic, but only those with clinical evidence to support their benefits should be considered. Experts have summarized the <a href="http://www.probioticchart.ca">tested products available in Canada</a> and the <a href="http://www.usprobioticguide.com">United States</a>, as well as the level of evidence, to help inform consumers and health-care providers.</p>
<p>These lists do not document every product, as many have not undergone the necessary testing in humans. More research is needed, so that probiotic use can be widened to have impacts across society and the ecosystem. </p>
<h2>A multi-billion dollar market</h2>
<p>The global market for probiotics is <a href="https://www.statista.com/statistics/821259/global-probioticsl-market-value/">forecast to reach to about US$69.3 billion by 2023</a>. This illustrates the interest of consumers and health-care providers in this area. In future, more products will be developed for specific health applications. </p>
<p>Because probiotic organisms produce molecules that pass from the intestine into the bloodstream, we may see treatments that could help <a href="https://www.ncbi.nlm.nih.gov/pubmed/27801892">the brain</a>, <a href="https://www.doi.org/10.1097/MPG.0000000000000187">lungs</a>, liver, <a href="http://www.dx.doi.org/10.1016/j.jmii.2015.10.003">skin</a> and <a href="http://www.dx.doi.org/10.1371/journal.pone.0187964">other organs</a>. Hopefully, researchers will compare probiotic strains to drugs to provide a perspective on where probiotics might fit in the spectrum of patient management. </p>
<p>Probiotics are not magic bullets or cures for all ills. For example, products tested so far have not proven valuable in the treatment of Crohn’s disease. Nevertheless, the use of beneficial microbes does represent an important field of science, with specific probiotic strains having the capacity to contribute to the well-being of humans and other life forms. </p>
<p>It is through scientific endeavour that such progress will be made to the betterment of humanity and the planet.</p>
<p>[ <em>Deep knowledge, daily.</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/121587/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregor Reid helped to develop and commercialize probiotic strains GR-1 and RC-14 but has had no financial interest in them for over 10 years.
He is Chief Scientific Officer for Seed, a company producing probiotic products.
He has provided advice on probiotics in the past three years to Seed, KGK Science, Acerus Pharma, Danone, Chr Hansen, Altmann, Kimberly Clark Corp., and Metagenics.
He is funded by NSERC, OMAFRA and Kimberly Clark. </span></em></p>From dietary supplements to poop transplants, probiotics are now a multi-billion dollar market.Gregor Reid, Professor at Schulich Medicine & Dentistry, Western UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1261312019-11-13T10:17:05Z2019-11-13T10:17:05ZKombucha, kimchi and yogurt: how fermented foods could be harmful to your health<figure><img src="https://images.theconversation.com/files/301371/original/file-20191112-178506-152mn9g.jpg?ixlib=rb-1.1.0&rect=16%2C0%2C5590%2C3732&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fermented foods such as yogurt, kimchi, and sauerkraut, are all popular sources of probiotics. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/probiotics-food-background-kimchi-beet-sauerkraut-1320880235?src=867b087e-53c5-491a-877e-d899f5dfbb90-1-32">Nina Firsova/ Shutterstock</a></span></figcaption></figure><p>Fermented foods have become very popular, thanks to claims about their nutritional properties and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723656/">reported health benefits</a>, such as improving digestion, boosting immunity and even helping people lose weight. Some of the most popular fermented foods include kefir, kombucha, sauerkraut, tempeh, natto, miso, kimchi and sourdough bread. </p>
<p>But though these fermented foods might offer us many health perks, most people aren’t aware that they might not work for everyone. For some people, fermented foods might cause serious health issues. </p>
<p>Fermented foods are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6117398/">loaded with microorganisms</a>, such as live bacteria and yeast (known as probiotics). However, not all microorganisms are bad. Many, like probiotics, are harmless and are <a href="https://www.webmd.com/digestive-disorders/what-are-probiotics#1">even beneficial to us</a>.</p>
<p>During the process of fermentation, probiotics convert carbohydrates (starch and sugar) into alcohol and/or acids. These act as a <a href="https://www.healthline.com/nutrition/fermentation">natural preservative</a> and give fermented foods their distinctive zest and flavour. Many factors affect fermentation, including the type of probiotic, the primary metabolites these microbes produce (such as lactic acid, or certain amino acids), and the food undergoing fermentation. For example, probiotic yogurt is produced by fermenting milk, most commonly with lactic acid bacteria that produce lactic acid.</p>
<p>Fermented foods contain high amounts of probiotics, which are generally considered safe for the majority of people. In fact, <a href="https://www.ncbi.nlm.nih.gov/pubmed/28945458">they’ve been shown to have</a> anti-oxidant, anti-microbial, anti-fungal, anti-inflammatory, anti-diabetic and anti-atherosclerotic activity. However, some people might experience severe side effects after consuming fermented foods.</p>
<h2>1. Bloating</h2>
<p>The most common reaction to fermented foods is a <a href="https://probioticscenter.org/bloating-and-probiotics/">temporary increase in gas and bloating</a>. This is the result of excess gas being produced after probiotics <a href="https://www.livestrong.com/article/324440-do-probiotics-kill-bad-bacteria/">kill harmful gut bacteria and fungi</a>. Probiotics secrete antimicrobial peptides that kill harmful pathogenic organisms like <em>Salmonella</em> and <em>E. Coli</em>. </p>
<p>A recent study showed this <a href="https://www.sciencedirect.com/science/article/pii/S2352939318300605">antimicrobial effect of probiotic Lactobacilli strains</a> found in commercial yogurt. Although bloating after eating probiotics seems to be a good sign that the harmful bacteria are being removed from the gut, some people might experience severe bloating, which can be very painful. </p>
<p>Drinking too much kombucha can also lead to excess sugar and calorie intake, which may also lead to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3264926/">bloating and gas</a>. </p>
<h2>2. Headaches and migraines</h2>
<p>Fermented foods rich in probiotics – including yogurt, sauerkraut and kimchi – <a href="https://www.sciencedirect.com/science/article/abs/pii/S0924224414001599">naturally contain biogenic amines</a> produced [during fermentation]. Amines are created by certain bacteria to <a href="https://www.ncbi.nlm.nih.gov/pubmed/30263683">break down the amino acids</a> in fermented foods. The most common ones found in probiotic-rich foods include <a href="https://www.ncbi.nlm.nih.gov/pubmed/27375596">histamine and tyramine</a>. </p>
<p>Some people are sensitive to histamine and other amines, and <a href="https://www.ncbi.nlm.nih.gov/pubmed/27699780">may experience headaches</a> after eating fermented foods. Because amines stimulate the central nervous system, they can increase or decrease blood flow, which can trigger headaches and migraines. One study found that low-histamine diets <a href="https://www.ncbi.nlm.nih.gov/pubmed/10779289">reduced headaches</a> in 75% of participants. Taking a probiotic supplement might be therefore preferred. </p>
<h2>3. Histamine intolerance</h2>
<p>Histamine is <a href="https://bdnutritionhealth.ca/2017/07/26/histamine-the-one-disadvantage-to-fermented-foods/">plentiful in fermented foods</a>. For most, our body’s specific enzymes will naturally digest them. However, some people don’t produce enough of these enzymes. This means histamine won’t be digested and will instead be absorbed into the bloodstream. </p>
<p>This can cause a range of <a href="https://www.ncbi.nlm.nih.gov/pubmed/16782524">histamine intolerance symptoms</a>. The most common are itching, headaches or migraines, runny nose (rhinitis), eye redness, fatigue, hives and digestive symptoms include diarrhoea, nausea and vomiting. </p>
<p>However, histamine intolerance can also cause more severe symptoms, including asthma, low blood pressure, irregular heart rate, circulatory collapse, sudden psychological changes (such as anxiety, aggressiveness, dizziness and lack of concentration) and sleep disorders. </p>
<h2>4. Food-borne illness</h2>
<p>While most fermented foods are safe, it’s still possible for them to get contaminated with bacteria that can cause illness. In 2012, there was an outbreak of 89 cases of <em>Salmonella</em> in the US because of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3810924/">unpasteurised tempeh</a>.</p>
<p>Two large outbreaks of <em>Escherichia coli</em>, were reported in South Korean schools in 2013 and 2014. They were associated with eating <a href="https://www.ncbi.nlm.nih.gov/pubmed/27557346">contaminated fermented vegetable kimchi</a>. </p>
<p>In most cases, probiotics found in fermented milk products such as cheese, yogurt and buttermilk can effectively prevent the growth of certain bacteria, such as <a href="https://academic.oup.com/femsre/article/36/4/815/52040"><em>Staphylococcus aureus</em></a> and <em>Staphylococcal enterotoxins</em> which can cause food poisoning. But in some cases probiotics fail and bacteria can actually secrete toxins, so the product may be hazardous.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301372/original/file-20191112-178516-8r6ija.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Staphylococcus aureus can cause skin and respiratory infections, as well as food poisoning.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/bacteria-staphylococcus-aureus-on-surface-skin-407372458?src=73e7fd33-427b-426f-a49f-1c175c44d41e-1-0">Kateryna Kon/ Shutterstock</a></span>
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<h2>5. Infection from probiotics</h2>
<p>Probiotics are generally safe for the vast majority of people. However, in rare cases, they can cause infection – especially in people who <a href="https://www.ncbi.nlm.nih.gov/pubmed/14679449">have a compromised immune system</a>. </p>
<p>A London study reported the first case of a 65-year-old diabetic patient whose liver abscess had been <a href="https://casereports.bmj.com/content/2017/bcr-2016-218423">caused by probiotic consumption</a>. Susceptible patients, such as those with compromised immunity, should be advised against consuming too many probiotics.</p>
<p>Treatment with probiotics <a href="https://jcm.asm.org/content/52/8/3124">can cause serious infections</a>, such as pneumonia in vulnerable people and systemic infections, including <a href="https://pediatrics.aappublications.org/content/115/1/178?sso=1&sso_redirect_count=1&nfstatus=401&nftoken=00000000-0000-0000-0000-000000000000&nfstatusdescription=ERROR%3a+No+local+token">sepsis</a> and <a href="https://thij.org/doi/10.14503/THIJ-15-5121">endocarditis</a>.</p>
<h2>6. Antibiotic resistance</h2>
<p>Probiotic bacteria can carry genes that confer resistance to antibiotics. These antibiotic resistance genes may pass to other bacteria found in the food chain and gastrointestinal tract via <a href="https://link.springer.com/article/10.1007/s00284-010-9856-2">horizontal gene transfer</a>. The most common antibiotic resistance genes carried by fermented foods are against <a href="https://www.sciencedirect.com/science/article/pii/B9780128023099000297">erythromycin and tetracycline</a>, which are used to treat respiratory infections and some sexually transmitted diseases.</p>
<p>Researchers found resistant probiotic strains in commercially available dietary supplements, which could mean resistance to several common types of antibiotics used to treat <a href="https://nutritionj.biomedcentral.com/articles/10.1186/s12937-015-0084-2">serious bacterial infections</a>. </p>
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Read more:
<a href="https://theconversation.com/antibiotic-resistance-researchers-have-directly-proven-that-bacteria-can-change-shape-inside-humans-to-avoid-antibiotics-124296">Antibiotic resistance: researchers have directly proven that bacteria can change shape inside humans to avoid antibiotics</a>
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<p>Research has also found six probiotic Bacillus strains found in food products (including kimchi, yogurt and olives) are also <a href="https://www.sciencedaily.com/releases/2019/06/190621144242.htm">resistant to several antibiotics</a>.</p>
<p>And, a recent Malaysian study showed probiotic <a href="https://www.ncbi.nlm.nih.gov/pubmed/31319614">Lactobacilli bacteria</a> in kefir carry resistance to numerous antibiotics, including ampicillin, penicillin and tetracycline. These are used to treat serious human diseases including bladder infections, pneumonia, gonorrhoea, and meningitis. </p>
<p>Another study also showed lactic acid bacteria found in Turkish dairy products were <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5960774/">resistant mainly to vancomycin antibiotic</a>, which is the drug of choice for treatment of <a href="https://www.nhs.uk/conditions/mrsa/">MRSA infection</a>.</p>
<p>While there are a wide variety of health benefits that can happen from consuming fermented foods, these may not work for everyone. While most people will be fine eating fermented foods, for some they could cause serious health problems.</p>
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<p><em>More on evidence-based articles about diets:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/do-you-get-diabetes-from-eating-too-much-sugar-95833?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=IsItTrue">Do you get diabetes from eating too much sugar?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/low-carb-paleo-or-fasting-which-diet-is-best-89685?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=IsItTrue">Low carb, Paleo or fasting – which diet is best?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/does-eating-at-night-make-you-fat-96804?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=IsItTrue">Does eating at night make you fat?</a></em></p></li>
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<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301912/original/file-20191115-66957-gxdqkd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/uk/newsletters/the-daily-newsletter-2?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=GeneralBannerA126131">Click here to subscribe to our newsletter and stay healthy with guidance you can trust.</a></em></p><img src="https://counter.theconversation.com/content/126131/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Manal Mohammed does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>While the probiotics found in fermented foods might have health benefits for most, these foods could cause serious harm to the health of others.Manal Mohammed, Lecturer, Medical Microbiology, University of WestminsterLicensed as Creative Commons – attribution, no derivatives.