tag:theconversation.com,2011:/us/topics/gut-health-28424/articlesGut health – The Conversation2024-02-02T12:54:34Ztag:theconversation.com,2011:article/2133232024-02-02T12:54:34Z2024-02-02T12:54:34ZGut microbiome: meet Lactobacillus brevis – a fermentation superstar<figure><img src="https://images.theconversation.com/files/572413/original/file-20240131-15-pvpmn2.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5605%2C3731&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The fermentation process is made possible thanks to this bacterium.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-eating-homemade-sauerkraut-white-table-1165110508">Pixel-Shot/ Shutterstock</a></span></figcaption></figure><p>Fermentation, one of the oldest food production and <a href="https://academic.oup.com/femsle/article/368/14/fnab085/6315325">preservation techniques</a>, has seen a huge revival in recent years. From craft beers and kombucha to yoghurt, sauerkraut and pickles, fermentation is central to producing these foods and drinks. There are different types of fermentation, one of which is lactic acid fermentation. </p>
<p>Lactic acid (also known as lactate) is best known for the <a href="https://www.scientificamerican.com/article/why-does-lactic-acid-buil">burning sensation</a> we feel in our muscles when exercising, which acts as a signal to the body to lower the intensity of the activity. </p>
<p>When it comes to fermentation and food storage, lactic acid is produced by lactic acid bacteria – necessary for creating a low pH environment that stops food spoiling. Some lactic acid bacteria produce lactic acid only. Others produce lactic acid as well as a <a href="https://www.sciencedirect.com/science/article/abs/pii/S2212429222000748">wide range</a> of other organic acids, which further acidify and create an environment that’s free of oxygen. <em>Lactobacillus brevis</em> is one such bacterium. </p>
<p>This microorganism, when viewed under the microscope, can be described as rod-shaped with rounded ends. It’s also Gram positive – meaning that it stains an indigo colour when tested using the Gram staining technique. It thrives at a temperature of 30-40°C and a slightly acidic pH (pH 4-6).</p>
<p>Most importantly, it’s a superstar when it comes to fermentation – producing lactic acid, acetic acid and carbon dioxide during the process. </p>
<p>Why might you want a microbe that makes organic acids and carbon dioxide? </p>
<p>One of the several food products where <em>Lactobacillus brevis</em> is naturally found is sauerkraut. Traditionally produced sauerkraut has long been known to be a <a href="https://www.sciencedirect.com/science/article/abs/pii/S0963996922001909">good source</a> of lactic acid bacteria. These bacteria are also found in pickles, in the tibicos grains used to make kefir and are a natural component of the gut microbiome.</p>
<p>During sauerkraut preparation, <em>Lactobacillus brevis</em> and other <a href="https://www.mdpi.com/2311-5637/9/12/1019">lactic acid bacteria</a>, such as <em>Lactococcus</em> and <em>Leuconostoc</em> species, help to ferment cabbage. During this process, the bacteria break down sugars in the cabbage, producing carbon dioxide and lactic acid, giving rise to the unique attributes of this fermented product.</p>
<figure class="align-center ">
<img alt="A person prepares a large jar of sauerkraut for fermentation." src="https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572414/original/file-20240131-29-2tz4ij.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"><em>Lactobacillus brevis</em> occurs naturally in sauerkraut.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-putting-tasty-sauerkraut-into-glass-2055659522">Pixel-Shot/ Shutterstock</a></span>
</figcaption>
</figure>
<p>When I open a jar of sauerkraut, I am always pleasantly surprised by the fizzing sound and appearance of the jar contents. It’s the production of the carbon dioxide that results in the impressive effervescence. The lactic acid and acetic acid are responsible for the tangy, slightly sour or acidic taste. </p>
<p>Also, because these are organic acids, they naturally lower the pH of the fermented cabbage – meaning that most contaminating microorganisms that favour a neutral pH will no longer be a part of the environment. Lactic acid bacteria also produce antimicrobial compounds such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8761470/">bacteriocins</a>, which prevent the growth of other contaminating bacteria. These effects make fermentation an excellent preservation technique. </p>
<p>In terms of gut health, the <a href="https://www.nature.com/articles/s41564-023-01426-7">microbiome is complex</a>. It’s unique to each person and can be influenced by several factors, including <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191956">diet</a>. Some lactic acid bacteria have been reported as being probiotic – meaning they’re live microorganisms that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352953/">improve gut health</a>. Also, although sauerkraut is promoted as containing probiotic bacteria, questions remain regarding the viability of these bacteria at the time of consumption – and whether they’re present in sufficient numbers to be beneficial. </p>
<p>Just as the microbiome itself is an ever-changing landscape, so too is this field of research as investigations continue to be carried out. But if you do decide to join me in adding sauerkraut to your diet for its unique taste and texture – and possible health benefits – bon appétit.</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/213323/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Leanne Timpson 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>Sauerkraut, pickles and craft beer wouldn’t exist without this microorganism.Leanne Timpson, Lecturer in Microbiology, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2213842024-01-21T12:59:06Z2024-01-21T12:59:06ZDietary fibre affects more than your colon: How the immune system, brain and overall health benefit too<figure><img src="https://images.theconversation.com/files/570412/original/file-20240119-19-bkynf2.jpg?ixlib=rb-1.1.0&rect=66%2C6%2C3923%2C2249&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Most people only consume about half of the recommended amount of dietary fibre, and it can negatively affect overall health.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/dietary-fibre-affects-more-than-your-colon-how-the-immune-system-brain-and-overall-health-benefit-too" width="100%" height="400"></iframe>
<p>There’s no shortage of advice about what to eat, including hype about the latest <a href="https://www.hsph.harvard.edu/nutritionsource/superfoods/">superfoods</a> that will help you <a href="https://www.npr.org/sections/thesalt/2015/04/11/398325030/eating-to-break-100-longevity-diet-tips-from-the-blue-zones">live to 100</a>, or about the newest <a href="https://food-guide.canada.ca/en/tips-for-healthy-eating/diets-food-trends/#section-2">restrictive diets</a> that claim to help you lose weight and look beautiful. As a researcher from the <a href="https://farncombe.mcmaster.ca/">Farncombe Family Digestive Health Research Institute</a>, I’m well aware that there is no universal “healthy diet” that will work for everyone. </p>
<p>However, most professionals would agree that a diet should be well balanced between the food groups, and it’s better to include more things like vegetables and <a href="https://doi.org/10.3390%2Fnu11081806">fermented foods</a> in your diet than restrict yourself unnecessarily. Eating foods that promote gut health improves your overall health too.</p>
<h2>Why is everyone so concerned about fibre?</h2>
<p>The importance of fibre has been known for decades. The late great surgeon and fibre researcher <a href="https://doi.org/10.1017/S0954422417000117">Denis Burkitt</a> once said, “If you pass small stools, you have to have large hospitals.” But dietary fibre does more than just help move your bowels. Fibre can be considered a <a href="https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/probiotics/faq-20058065">prebiotic nutrient</a>. </p>
<p>Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut. <a href="https://doi.org/10.3390%2Ffoods8030092">These microbes then help digest foods</a> for us so we can obtain more nutrients, promote gut barrier integrity and prevent the growth of harmful bacteria. </p>
<figure class="align-center ">
<img alt="High-fibre foods against the outline of intestines" src="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.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">Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Fibres can also have microbe-independent effects on our immune system when they <a href="https://doi.org/10.1111/bph.14871">interact directly with receptors expressed by our cells</a>. These beneficial effects may even help teach the immune system to be more tolerant and reduce inflammation.</p>
<h2>Getting enough dietary fibre?</h2>
<p>Probably not. The so-called <a href="https://doi.org/10.3390%2Fnu15122749">western diet</a> is low in fibre and filled with ultra-processed foods. The <a href="https://www.canada.ca/en/health-canada/services/nutrients/fibre.html">recommendation for daily fibre</a> is between <a href="https://doi.org/10.1038/s41575-020-00375-4">25-38 grams depending on factors like age, sex and activity level</a>. Most people consume about half of the recommendation, and it can negatively affect overall health. </p>
<p>Good sources of dietary fibre include whole grains, fruits and vegetables, beans and legumes, and nuts and seeds. There is a lot of emphasis on soluble fibres and less on insoluble fibres, but in reality, most foods will contain a mixture of both, and they each <a href="https://www.healthline.com/health/soluble-vs-insoluble-fiber%23risks">have their merits</a>. </p>
<p>High fibre snacks are also gaining popularity. With an estimated global value of US$7 billion in 2022, the <a href="https://www.precedenceresearch.com/prebiotic-ingredients-market#:%7E:text=The%2520global%2520prebiotic%2520ingredients%2520market,13.25%2525%2520from%25202022%2520to%25202030">value of the prebiotic ingredient market</a> is expected to triple by 2032.</p>
<h2>The benefits of dietary fibre</h2>
<figure class="align-right ">
<img alt="Diagram of a human with arrows linking brain and intestines" src="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?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">Fibre is associated with overall health and brain health through the gut-brain axis.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>There’s plenty of evidence supporting the benefits of dietary fibre. Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the <a href="https://my.clevelandclinic.org/health/body/the-gut-brain-connection">gut-brain axis</a>. Diets low in fibre have been associated with gastrointestinal disorders such as irritable bowel syndrome or inflammatory bowel disease. </p>
<p>On the other hand, consuming adequate fibre also <a href="https://doi.org/10.1038/s41575-020-00375-4">reduces the risk and mortality associated with cardiovascular diseases and obesity</a>. There are studies that show <a href="https://doi.org/10.3390/nu13072159">improvements of cognitive function with certain types of fibre</a>. </p>
<p>There are some gastrointestinal diseases, like Celiac disease, which are not typically associated with the benefits of dietary fibre. However, <a href="https://doi.org/10.1038/s41575-020-00375-4">there isn’t a consensus</a> to the specific type of fibre and dose that would be beneficial in treating most diseases.</p>
<h2>Not all fibre is good fibre</h2>
<p>Shockingly, not all fibre is good for you. Fibre is used as an umbrella term for indigestible plant polysaccharides, so there are many different types with varying fermentability, solubility and viscosity in the gut. </p>
<p>To make things more complex, <a href="https://doi.org/10.3389/fped.2020.620189">the source matters too</a>. Fibre from one plant isn’t the same as fibre from another plant. Additionally, the old proverb, “too much good is not good” rings true, where overconsumption of fibre supplements can cause symptoms such as constipation, bloating and gas. This is partly due to the differences in gut microbiomes that affect the ability to metabolize fibre to produce beneficial molecules like short-chain fatty acids. </p>
<p>In some cases, such as inflammatory bowel disease patients, lack of microbes with the capacity to digest fibre may allow intact fibres to <a href="https://doi.org/10.1053/j.gastro.2022.09.034">interact with intestinal cells directly and exert pro-inflammatory effects</a>. Recent evidence has even shown that excessively high consumption of soluble fibres, such as inulin, a common supplement, <a href="https://doi.org/10.1053/j.gastro.2023.10.012">can increase the risk of colon cancer development in an experimental animal model</a>.</p>
<h2>Part of a healthy diet</h2>
<p>Dietary fibre is an important part of a healthy diet that can promote both gut and overall health. Fibre helps you feel more satisfied after meals and helps to regulate your blood sugar and cholesterol. Do your best to consume fibre as part of your diet, and when needed, take only the dose of supplements as recommended. </p>
<p>Prebiotics promote the growth of gut microbes that can affect gut health and immunity in the context of many different diseases, although not all fibres are created equal. While fibre won’t cure illness, diet is a great addition to medicines and treatment strategies that can improve their efficacy.</p><img src="https://counter.theconversation.com/content/221384/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Wulczynski 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>Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the gut-brain axis. But not all fibres are created equal.Mark Wulczynski, Medical Sciences PhD Candidate, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2191782023-12-13T12:59:22Z2023-12-13T12:59:22ZMicroscopic colitis explained – and why it’s often mistaken for IBS<figure><img src="https://images.theconversation.com/files/565160/original/file-20231212-19-z2meix.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C7348%2C4616&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/girl-having-stomachache-young-woman-suffering-2118544205">Body Stock/Shutterstock</a></span></figcaption></figure><p>In 1976, a Swedish pathologist, C.G Lindström, published a <a href="https://pubmed.ncbi.nlm.nih.gov/934705/">paper</a> describing a colonic anomaly. Through his microscope, he noted that part of the large intestinal wall of one of his patients was thickened. The patient, whose large intestine had been so thoroughly examined, suffered from chronic diarrhoea. The pathologist suggested naming the new entity collagenous colitis, with “colitis” referring to inflammation of the large intestine.</p>
<p>Ten years later, an American pathologist, A.J. Lazenby, <a href="https://doi.org/10.1016/0046-8177(89)90198-6">noted</a> an increased concentration of white blood cells in the colonic wall in patients experiencing similar chronic diarrhoea. She named the condition lymphocytic colitis. </p>
<p>Since patients diagnosed with these two new diseases experienced identical symptoms, had tissue changes only visible through a microscope and responded to the same medication, they were seen as suffering from one entity: microscopic colitis. </p>
<p>Although the medical community gradually became aware of microscopic colitis, the condition was rarely diagnosed. Several factors likely contributed to this, such as the absence of blood in the stools, which is rightly considered a serious symptom requiring a thorough and prompt investigation. </p>
<p>Also, <a href="https://doi.org/10.1111/apt.13573">studies</a> have found that microscopic colitis is often misdiagnosed as irritable bowel syndrome, a functional disorder (arising from changes in how the body works, rather than a disease). </p>
<p>Another explanation is, of course, the healthcare resources required to diagnose the condition. </p>
<h2>More people being diagnosed</h2>
<p>First, an examination of the large intestine must be undertaken during which tissue samples have to be collected and then these tissue samples must be properly examined by a pathologist who knows what changes to look for. </p>
<p>However, as the awareness of the disease has increased along with the access to the healthcare resources described above, more people are being diagnosed with microscopic colitis. </p>
<p>In a study examining the diagnosis of microscopic colitis in Sweden from 1990 to 2015, my colleagues and I noted a sharp rise in the <a href="https://doi.org/10.1111/apt.15246">curve</a> depicting the number of people diagnosed per year for the first 20 years, followed by a plateau. </p>
<p>What we also noted was that 70% of people with the condition were women and that the average age at diagnosis was around 60 years – although 25% were younger than 45. </p>
<p>In another of our <a href="https://doi.org/10.1080/00365521.2018.1543446">studies</a>, we investigated what symptoms these patients experienced. Almost everyone suffered from watery diarrhoea (without blood). Other symptoms included abdominal pain, weight loss, nausea and some patients even experienced faecal incontinence. </p>
<p>Among gastroenterologists, it is well known that patients with this disease often experience stress and anxiety related to their bowel movements. Some may even avoid going outdoors for fear of not making it to a restroom in time. And when going out they always know where the nearest toilet is. </p>
<figure class="align-center ">
<img alt="Woman staring out a window" src="https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565161/original/file-20231212-23-bdnmji.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">Some people with microscopic colitis will even avoid going out.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-worried-woman-looking-through-window-1681794337">Marjan Apostolovic/Shutterstock</a></span>
</figcaption>
</figure>
<p>Unfortunately, we do not yet know what causes the disease, but it is considered to be a complex combination of genetic and environmental factors as well as an imbalanced immune system. </p>
<p>Smoking also seems to be a risk factor. People with microscopic colitis who smoke, are diagnosed at a younger age and have more symptoms. On the bright side, there are effective treatments, such as the steroid drug budesonide, usually without any serious side-effects. And people who do smoke and quit may even experience an alleviation of their symptoms. </p>
<p>Properly diagnosing and treating microscopic colitis can make a huge difference for people with the condition.</p><img src="https://counter.theconversation.com/content/219178/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Bergman has previously received funding from Mag-Tarmfonden.</span></em></p>Some people with microscopic colitis avoid going outdoors.David Bergman, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2141692023-10-02T14:37:35Z2023-10-02T14:37:35ZBrush your teeth! Bad oral hygiene linked to cancer, heart attacks and renal failure<p><em>It’s normal to have bacteria in your mouth. But harmful bacteria have been linked to a host of health problems. Medical scientist Glenda Davison and microbiologist Yvonne Prince, who have <a href="https://www.mdpi.com/2227-9059/11/1/3">researched</a> the oral cavity, explain why it’s so important to practise good oral hygiene.</em></p>
<h2>Can poor oral hygiene lead to serious diseases? Why and how?</h2>
<p>Abnormal bacterial communities in the oral cavity have been linked to <a href="https://www.niddk.nih.gov/health-information/liver-disease#:%7E:text=There%20are%20many%20kinds%20of,one%20sign%20of%20liver%20disease.">liver disease</a>, <a href="https://www.ncbi.nlm.nih.gov/books/NBK519012/#:%7E:text=The%20term%20renal%20failure%20denotes,two%20kinds%20of%20kidney%20failure.">renal failure</a>, <a href="https://www.who.int/health-topics/cancer#tab=tab_1">cancers</a>, <a href="https://www.webmd.com/heart-disease/heart-disease-types-causes-symptoms">heart disease</a> and <a href="https://www.cdc.gov/bloodpressure/about.htm">hypertension</a>.</p>
<p>The <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/oral-cavity">oral cavity</a> is the door to the <a href="https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works">gastrointestinal tract</a> and the rest of the body. </p>
<p>Like the gut, the mouth is home to several diverse colonies of bacteria, fungi, viruses and <a href="https://www.cdc.gov/parasites/about.html">protozoa</a>. It’s the second largest microbial community in humans, after the gut.</p>
<p>More than 700 species of microorganisms reside in the mouth. New technologies, such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC523561/">16S rRNA analysis</a>, have allowed researchers to study their genetic makeup and family trees. </p>
<p>These <a href="https://askthedentist.com/oral-microbiome/">microbes</a> are found all over the mouth: in and around the teeth, the gums, tongue, palate and saliva. They usually remain stable during our lifetime but if the balance in the bacterial community is disrupted, harmful bacteria may become dominant. This can lead to bleeding gums and oral diseases such as <a href="https://www.ncbi.nlm.nih.gov/books/NBK279593/">gingivitis and periodontitis</a>.</p>
<h2>How do problems in the mouth lead to other illnesses?</h2>
<p>Changes in the <a href="https://www.news-medical.net/health/pH-in-the-Human-Body.aspx">pH</a> (acidity or alkalinity), temperature and oxygen in the oral cavity are known to lead to abnormal growth of groups of bacteria which are usually harmless. When they become dominant, they can cause disease. </p>
<p>This disruption in the oral <a href="https://www.hsph.harvard.edu/nutritionsource/microbiome/#:%7E:text=The%20microbiome%20consists%20of%20microbes,symbiotic%20microbiota%20coexist%20without%20probleguitms.">biota</a> causes inflammation and the slow development of periodontitis, bleeding gums and tooth decay. As the gum disease destroys the gum and begins to erode the bone, inflammatory molecules called <a href="https://www.cancer.org/cancer/managing-cancer/treatment-types/immunotherapy/cytokines.html#:%7E:text=Cytokines%20are%20small%20proteins%20that,body's%20immune%20and%20inflammation%20responses.">cytokines</a> can enter the blood stream. </p>
<p>These chemicals activate immune cells and can result in low grade chronic inflammation with the development of diseases such as <a href="https://diabetes.org/diabetes/type-2">type II diabetes</a>, <a href="https://www.hopkinsmedicine.org/health/conditions-and-diseases/atherosclerosis#:%7E:text=Atherosclerosis%20thickening%20or%20hardening%20of,walls%20become%20thickened%20and%20stiff.">atherosclerosis</a> or thickening of the arteries and many others, even obesity. The bacteria themselves can also move from the gums into the surrounding tissue and <a href="https://www.sciencedirect.com/science/article/pii/S2213453018301642">release toxins</a> which can move throughout the body. </p>
<p>Similarly, the gut hosts more than 1,000 species of bacteria which reside in the <a href="https://www.ncbi.nlm.nih.gov/books/NBK507857/#:%7E:text=The%20large%20intestine%20is%20responsible,descending%20colon%2C%20and%20sigmoid%20colon.">large intestine</a> and play a vital role in digestion, absorption, immunity and protection against toxins and harmful bacteria. </p>
<p>Human beings cannot live without a healthy, diverse gut biota. If this well-balanced community of microbes is disturbed and not restored, gastrointestinal disorders can be experienced. </p>
<p>Recent research has linked an abnormal gut biome to diseases as diverse as <a href="https://www.immunology.org/public-information/bitesized-immunology/immune-dysfunction/autoimmunity-introduction">autoimmunity</a>, obesity, cardiovascular disease and even <a href="https://www.healthline.com/nutrition/gut-microbiome-and-health">Alzheimer’s</a>.</p>
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<strong>
Read more:
<a href="https://theconversation.com/microbiome-certain-gut-microbes-may-warn-of-alzheimers-disease-long-before-the-first-symptoms-begin-207999">Microbiome: certain gut microbes may warn of Alzheimer's disease long before the first symptoms begin</a>
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<h2>Where do bacteria in the body come from?</h2>
<p>It all starts with our microbes, tiny organisms which share our bodies and are vital to the health of human beings. There are <a href="https://www.voanews.com/a/research-estimates-we-are-only-about-43-percent-human/4932876.html">39 trillion microbes</a> in the human body, outnumbering the estimated 30 trillion human cells, and they inhabit almost every organ and crevice in the human body. They can be found in the gut, skin, lung, seminal and vaginal fluid, eyes, scalp and mouth. </p>
<p>Each of these habitats has its own environment, attracting different organisms which adapt to their surroundings and make it their home. They live in synergy with each other and the surrounding tissue. If this relationship is disrupted it can result in disease.</p>
<p>Most of these microbes come from our mothers and enter our bodies when we are born. The womb is sterile but as the baby moves down the birth canal and enters the outside world, bacteria and other microbes occupy the newborn infant and create a unique ecosystem called the <a href="https://www.sciencefocus.com/the-human-body/human-microbiome">human microbiome</a>.</p>
<p>As we grow and begin to explore the world, these microorganisms become more diverse and varied and are influenced by our diets, lifestyles, interactions with animals and the environment. It is important to maintain this balance to reduce the risk of developing disease. </p>
<h2>What should people do to avoid these risks?</h2>
<p>Good dental hygiene includes regular dental check-ups, preventing the build-up of <a href="https://www.webmd.com/oral-health/plaque-and-your-teeth">plaque</a> by brushing your teeth regularly, and avoiding foods high in carbohydrates and sugar, which can lead to increased tooth decay and cavities. </p>
<p>To further support the balance of the bacteria in the mouth it is recommended that foods rich in <a href="https://www.medicalnewstoday.com/articles/301506">antioxidants</a>, such as fresh fruit and vegetables, are included in our diet. </p>
<p>Dentists also recommend avoiding the use of <a href="https://pubmed.ncbi.nlm.nih.gov/31709856/">antibacterial mouth washes</a>, which have been shown to disrupt the balance of microbes. Overuse can lead to disturbances and stimulate species of bacteria that could cause disease. </p>
<p>Elevated <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9678961/">levels of stress</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7182722/">lack of exercise</a> have also been linked to disruptions in the balance of the oral biota. So a well balanced diet with enough rest, accompanied by<a href="https://www.medicalnewstoday.com/articles/324708#_noHeaderPrefixedContent"> good dental hygiene</a>, is recommended. </p>
<p>The mouth is the door to the gut and the rest of the body. Ensuring the harmony of the microbes that live there is important to reduce the risk of disease.</p><img src="https://counter.theconversation.com/content/214169/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Glenda Mary Davison receives funding from the South African Medical Research Foundation and serves as the Interim DSI-NRF SARChI chair in cardiometabolic health which is funded by Nedbank.</span></em></p><p class="fine-print"><em><span>Yvonne Prince 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>Oral hygiene is often neglected but research has shown that abnormal bacterial communities in the mouth can cause serious disease.Glenda Mary Davison, Associate Professor, Cape Peninsula University of TechnologyYvonne Prince, PhD in Biomedical Science (Microbiology), Cape Peninsula University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2051592023-07-03T11:53:03Z2023-07-03T11:53:03ZFiber 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<figure><img src="https://images.theconversation.com/files/529655/original/file-20230601-21-meilfi.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Whole foods like unprocessed fruits, vegetables and grains are typically high in fiber.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/pattern-of-variety-fresh-of-organic-fruits-and-royalty-free-image/1455279498">Tanja Ivanova/Moment via Getty Images</a></span></figcaption></figure><p>Fiber might just be the key to healthy weight management – and nature packages it in perfectly balanced ratios with carbs when you eat them as whole foods. Think unprocessed fruits, vegetables, whole grains, beans, nuts and seeds. Research suggests that carbohydrates are meant to come packaged in <a href="https://doi.org/10.1007/s00394-019-02165-4">nature-balanced ratios</a> of total carbohydrates to fiber. In fact, certain types of fiber affect how completely your body <a href="https://doi.org/10.1038/s41467-023-38778-x">absorbs carbohydrates</a> and <a href="https://doi.org/10.1016/j.bcdf.2017.07.005">tells your cells how to process them</a> once they are absorbed.</p>
<p>Fiber slows the absorption of sugar in your gut. It also orchestrates the fundamental biology that recent blockbuster weight loss drugs like <a href="https://theconversation.com/drugs-that-melt-away-pounds-still-present-more-questions-than-answers-but-ozempic-wegovy-and-mounjaro-could-be-key-tools-in-reducing-the-obesity-epidemic-205549">Wegovy and Ozempic</a> tap into, but in a natural way. Your microbiome <a href="https://doi.org/10.3389/fendo.2020.00025">transforms fiber into signals</a> that stimulate the gut hormones that are the natural forms of these drugs. These in turn regulate how rapidly your stomach empties, how tightly your <a href="https://doi.org/10.2337/ds16-0026">blood sugar levels</a> are controlled and even how hungry you feel. </p>
<p>It’s as if unprocessed carbohydrates naturally come wrapped and packaged with their own instruction manual for your body on how to digest them.</p>
<p>I am a <a href="https://gastro.uw.edu/faculty/christopher-j-damman-md-ma">physician scientist and gastroenterologist</a> who has spent over 20 years studying how <a href="https://gutbites.org/">food affects the gut microbiome</a> and metabolism. The research is clear – fiber is important not just for happy bowel movements, but also for your blood sugar, weight and overall health.</p>
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<figcaption><span class="caption">Different types of carbs have different effects on the body.</span></figcaption>
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<h2>Carbohydrates without their wrappers</h2>
<p>Unfortunately, most Americans get the majority of their carbohydrates stripped of their natural fibers. Modern processed grains like white rice and white flour as well as many ultraprocessed foods like some sugary breakfast cereals, packaged snacks and juices have removed these fibers. They essentially come unwrapped and without instructions for the body on how much it should absorb and how it should process them. In fact, <a href="https://doi.org/10.1177%2F1559827615588079">only 5% of Americans</a> eat the recommended amount of carbohydrates with enough of their natural packaging intact. Guidelines recommend <a href="https://doi.org/10.1136%2Fbmj-2020-054370">at least 25 to 30 grams</a> of fiber a day from food.</p>
<p>It may not be surprising that lack of fiber <a href="https://doi.org/10.1371/journal.pmed.1003053">contributes to diabetes and obesity</a>. What is surprising is that the fiber gap also likely contributes to <a href="https://doi.org/10.1016/s2468-1253(19)30257-2">heart disease</a>, certain <a href="https://doi.org/10.1093/ajcn/nqaa161">types of cancer</a> and maybe even <a href="https://doi.org/10.3233/jad-215493">Alzheimer’s disease</a>.</p>
<p>One popular approach to mitigating some of the ill health effects of low fiber and high refined carbohydrates has been to <a href="https://doi.org/10.1016/j.jacl.2019.08.003">limit carbohydrate intake</a>. Such approaches include the low-carb, keto, paleo and Atkins diets. Each diet is a variation on a similar theme of limiting carbohydrates to varying amounts in different ways.</p>
<p>There is scientific backing to the benefits of some of these diets. Research shows that limiting carbohydrates <a href="https://doi.org/10.3389/fnut.2021.702802">induces ketosis</a>, a biological process that frees energy from fat reserves during starvation and prolonged exercise. Low-carbohydrate diets can also help people lose weight and <a href="https://doi.org/10.1038/s41392-021-00831-w">lead to improvements</a> in blood pressure and inflammation.</p>
<p>That said, some keto diets may have negative effects on <a href="https://doi.org/10.3390/genes10070534">gut health</a>. It is also unknown how they may affect <a href="https://doi.org/10.3390/nu14173499">heart health, some forms of cancer</a> and other conditions in the long term.</p>
<p>Even more confusing, research shows that people with diets high in plant-sourced carbohydrates, like the Mediterranean diet, tend to lead the <a href="https://doi.org/10.3390%2Fnu13082540">longest and healthiest lives</a>. How can this be reconciled with studies that suggest that low-carbohydrate diets can benefit metabolic health?</p>
<h2>Is a carb a carb?</h2>
<p>The answer may have to do with the <a href="https://doi.org/10.1093%2Fjn%2Fnxac039">types of carbohydrates</a> that studies are evaluating. Limiting simple sugars and refined carbohydrates may improve certain aspects of metabolic health, as these are some of the most easily digested and absorbed calories. But a more sustainable and comprehensive way of improving health may be <a href="https://doi.org/10.3390%2Fnu12103045">increasing the percentage</a> of unprocessed, more complex and slowly absorbed carbohydrates that come with their natural packages and instructions intact – those that have fiber. </p>
<p>These natural carbohydrates can be found in whole grains, beans, nuts, seeds, fruits and vegetables. They come in ratios of total carbohydrate to fiber that <a href="https://doi.org/10.1371%2Fjournal.pone.0231572">rarely exceed 10-to-1 and are often 5-to-1 or lower</a>. Eating mostly whole foods is a simple way to ensure you’re consuming quality carbohydrates with the right ratios.</p>
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<span class="caption">Fruits and vegetables typically come in ideal total carbohydrate-to-fiber ratios.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-asian-woman-shopping-fruits-and-vegetables-in-royalty-free-image/1477272111">Oscar Wong/Moment via Getty Images</a></span>
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<p>But who doesn’t like to have a big bowl of pasta or cake with ice cream on occasion? Focusing on packaged processed foods that maintain carb-to-fiber ratios of at least as low as 10-to-1 or ideally 5-to-1 can help you make the best choices when picking more processed foods at the store. Take a look at the nutrition facts label and simply divide total carbohydrates by dietary fiber.</p>
<p>On occasions when you’re eating out or celebrating someone’s birthday, consider taking a fiber supplement with your meal. One pilot study found that a <a href="https://doi.org/10.2337/db22-836-P">supplement containing a blend of fibers</a> decreased the blood sugar spike – an increase in glucose levels in the blood that if <a href="https://doi.org/10.1017/S0029665122000088">too high can damage the body over time</a> – after a meal in healthy individuals by roughly 30%.</p>
<h2>Listen to your body</h2>
<p>While almost all fiber is generally good for health in most people, not all fiber affects the <a href="https://gutbites.org/2022/05/01/are-all-fibers-to-be-plated-equal/">body in the same way</a>. Consuming a <a href="https://doi.org/10.1111/apt.15129">range of different types</a> of fiber generally helps ensure a <a href="https://theconversation.com/hangry-bacteria-in-your-gut-microbiome-are-linked-to-chronic-disease-feeding-them-what-they-need-could-lead-to-happier-cells-and-a-healthier-body-199486">diverse microbiome</a>, which is linked to gut and overall health.</p>
<p>But certain medical conditions might preclude consuming certain types of fiber. For example, some people can be particularly sensitive to one <a href="https://doi.org/10.1136/gutjnl-2021-326284">class of fiber called FODMAPS</a> – fermentable oligosaccharides, disaccharides, monosaccharides and polyols – that are more readily fermented in the upper part of the gut and can contribute to symptoms of irritable bowel syndrome like bloating and diarrhea. <a href="https://www.health.harvard.edu/diseases-and-conditions/a-new-diet-to-manage-irritable-bowel-syndrome">High-FODMAP foods</a> include many processed foods that contain inulin, garlic powder and onion powder, as well as whole foods including those in the onion family, dairy products, some fruits and vegetables.</p>
<p>Listen to how your body responds to different high-fiber foods. Start low and go slow as you reintroduce foods like beans, seeds, nuts, fruits and vegetables to your diet. If you have trouble increasing your fiber intake, talk with your health care provider.</p>
<p>Tools like this <a href="https://gutbites.org/carb-fiber-ratio-calculator/">online calculator</a> I’ve created can also help you find the highest-quality foods with healthy fiber and other nutrient ratios. It can also show you what proportions of fiber to add back to sugary foods to help achieve healthy ratios.</p>
<p>I wouldn’t endorse eating sweets all the time, but as my three daughters like to remind me, it’s important to enjoy yourself every once in a while. And when you do, consider putting the carbs back in their fiber wrappers. It’s hard to improve upon nature’s design.</p><img src="https://counter.theconversation.com/content/205159/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Damman is on the scientific advisory board at BCD Biosciences and Supergut.</span></em></p>Many processed foods strip carbs of their natural fibers. Eating foods with an ideal total carbohydrate-to-fiber ratio can help with weight management and improve overall health.Christopher Damman, Associate Professor of Gastroenterology, School of Medicine, University of WashingtonLicensed 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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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>
<figure class="align-center ">
<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">
<figcaption>
<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>
</figcaption>
</figure>
<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>
<hr>
<p>
<em>
<strong>
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>
</strong>
</em>
</p>
<hr>
<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/1908432022-11-01T22:37:10Z2022-11-01T22:37:10ZFeeling bloated, hungry or bored after salad? These tips might help<figure><img src="https://images.theconversation.com/files/485779/original/file-20220921-25-27uhle.jpg?ixlib=rb-1.1.0&rect=0%2C90%2C6016%2C3917&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/nnN2I7oG6iY">Photo by Ralph (Ravi) Kayden on Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Salads are great for our health.</p>
<p>They are nutritious, packed full of gut-loving fibre, micronutrients, vitamins, minerals and antioxidants.</p>
<p>However, some people can experience certain downsides after eating salad, including feeling bored, bloated or even still hungry. </p>
<p>Here are some tips to help you make the most of your salad-eating habits as the weather warms up.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/are-home-brand-foods-healthy-if-you-read-the-label-you-may-be-pleasantly-surprised-189445">Are home-brand foods healthy? If you read the label, you may be pleasantly surprised</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C1920%2C1264&q=45&auto=format&w=1000&fit=clip"><img alt="A salad sits on a table near an olive oil carafe" src="https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C1920%2C1264&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485777/original/file-20220921-16-tbz6j6.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">Salads are great for our health.</span>
<span class="attribution"><span class="source">Image by Jill Wellington from Pixabay</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Keep yourself fuller for longer</h2>
<p>Salads are naturally low in calories or kilojoules. This is because salads mostly contain vegetables, which have a high water content. </p>
<p>This may mean you don’t feel very satisfied after eating your salad – making it hard to stay full until your next meal.</p>
<p>Instead of eating a salad and then later reaching for something less healthy to fill up on, you can stay fuller for longer by including all three macronutrients in your salad:</p>
<ol>
<li><p>a healthy carbohydrate source (pumpkin, sweet potato, parsnips, taro, brown rice, quinoa, barley or brown pasta)</p></li>
<li><p>a healthy fat source (avocado, olive oil, toasted seeds or nuts)</p></li>
<li><p>a lean protein source (eggs, fish, chicken, tofu, tempeh, lentils or legumes).</p></li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A salad with avocado and brown bread sits on a table." src="https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485780/original/file-20220921-26-5jlath.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 stay fuller for longer by including all three macronutrients in your salad.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/vegetable-salad-with-wheat-bread-on-the-side-1213710/">Photo by Dana Tentis/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Reduce bloating</h2>
<p>Many people experience bloating and/or gut upset when they eat a lot of salad.</p>
<p>This commonly occurs if someone is going quickly from a less healthy, low-fibre diet to a healthier, high-fibre diet. </p>
<p>It happens because your gut microbes are multiplying and producing lots of plant-digesting enzymes (which is great for your gut health!).</p>
<p>However, your gut needs some time to adapt and adjust over time. You can help alleviate any discomfort by: </p>
<ol>
<li><p>taking a <a href="https://link.springer.com/article/10.1007/s40279-022-01649-4">short walk</a> or doing some stretching after eating your salad. This has been shown to reduce bloating as it loosens up the gut muscles and helps release any trapped gas </p></li>
<li><p>being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7219460/">mindful</a> of how you are preparing lentils and legumes. Ensure they are thoroughly rinsed and only include ¼ cup of them (soaked) to begin with if they are something new in your diet</p></li>
<li><p>eating your salad mindfully. A non-relaxed, uptight gut or a gut that has recently been irritated by an illness can mean your gut is not as efficient in absorbing gas. This can trigger bloating as the gas gets “trapped”</p></li>
<li><p>cooking some of the vegetables in your salad. Applying temperature or heat to your vegetables can help break them down and make them easier to digest</p></li>
<li><p>considering your symptoms. If you experience extreme abdominal pain, irregular bowel habits (including chronic diarrhoea or constipation, or alternating diarrhoea and constipation) and a bloated stomach after eating salad it may indicate you are suffering from irritable bowel syndrome (IBS). Please see an accredited practising dietitian who can make an assessment and diagnose IBS, help you identify your triggers and manage your symptoms </p></li>
<li><p>being mindful of your current health conditions or treatments. For example, if you are undergoing chemotherapy treatment, some drugs can slow down your digestion. This may mean some vegetables and other high-fibre foods in your salad upset your gut. Again, speaking with an accredited practising dietitian is the best way to receive evidence-based advice on how to manage this. </p></li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A person tears up kale leaves to drop them in a salad." src="https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485781/original/file-20220921-24-a4hdau.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Consider cooking some of the ingredients in your salad.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/0geTqSZ76Xg">Photo by Max Delsid on Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Keep salad boredom at bay</h2>
<p>Stuck on what makes a good salad? Here’s Lauren’s tried and tested formula, based on six categories of ingredients: </p>
<ol>
<li><p>leaves, such as lettuce, rocket or spinach</p></li>
<li><p>something sweet and juicy, such as tomato, pear, mango, peach or whatever is in season</p></li>
<li><p>something with crunch, such as carrot, capsicum or broccolini</p></li>
<li><p>a type of nut, such as cashew or macadamia</p></li>
<li><p>a cheese, such as feta, bocconcini, mature cheddar, parmesan, edam</p></li>
<li><p>something fragrant, such as mint, parsley, basil or coriander.</p></li>
</ol>
<p>To make the salad into a complete meal, add a healthy carbohydrate, fat and protein source (the three macronutrients we mentioned earlier).</p>
<p>The bottom line? Eating salads is a great way to have a healthy, diverse diet. With these tweaks, you can make the most of the summer weather ahead!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-are-sugar-rushes-real-161494">Curious Kids: are sugar rushes real?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/190843/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lauren Ball receives funding from the National Health and Medical Research Council and Queensland Health. She is a Director of Dietitians Australia.</span></em></p><p class="fine-print"><em><span>Emily Burch 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>No, you’re not imagining it. Some people really do experience bloating or gut upset when they eat a lot of salad.Lauren Ball, Professor of Community Health and Wellbeing, The University of QueenslandEmily Burch, Dietitian and Researcher, The University of QueenslandLicensed 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>
<hr>
<p>
<em>
<strong>
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>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<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/1777482022-03-17T01:42:27Z2022-03-17T01:42:27ZA poo dose a day may keep bipolar away. When it comes to mental health, what else could poo do?<figure><img src="https://images.theconversation.com/files/451146/original/file-20220309-793-6zoqhi.jpg?ixlib=rb-1.1.0&rect=1%2C28%2C997%2C669&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/woman-toilet-160277366">Shutterstock</a></span></figcaption></figure><p>In a world first, two Australians with bipolar have had poo transplants, their symptoms improved, and their cases written up in <a href="https://journals.sagepub.com/doi/abs/10.1177/0004867420912834">peer-reviewed</a> <a href="https://pubmed.ncbi.nlm.nih.gov/35165993/">journals</a>.</p>
<p>One of us (Parker) treated the second of these patients with so-called faecal microbiota transplantation, and published his case study in recent weeks. The other (Green) is part of a team recruiting people with depression to a poo transplant clinical trial.</p>
<p>We’d be the first to admit it’s early days for this type of treatment for bipolar or other mental health issues. There are many hurdles before we could see poo transplants for these become commonplace.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1500188402901159937"}"></div></p>
<p>So we do not advocate people abandon their existing medication, try this at home or demand their psychiatrist offer them a “crapsule” (a poo capsule and yes, that’s a word).</p>
<p>Yet the limited results for bipolar so far are promising. Here’s what the evidence tells us about the prospect of poo transplants for mental health.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/poo-transplants-beyond-the-yuck-factor-what-works-what-doesnt-and-what-we-still-dont-know-82265">Poo transplants beyond the yuck factor: what works, what doesn't and what we still don't know</a>
</strong>
</em>
</p>
<hr>
<h2>Let’s start with bipolar</h2>
<p>There are different types of <a href="https://theconversation.com/what-is-bipolar-disorder-the-condition-kanye-west-lives-with-143198">bipolar disorder</a>. This is when people have distinct periods of <a href="https://www.mind.org.uk/information-support/types-of-mental-health-problems/hypomania-and-mania/about-hypomania-and-mania/">mania (or a form known as hypomania)</a> – with, for example, elevated mood, increased activity and decreased sleep – and periods of depression.</p>
<p>People with bipolar usually take medication to manage their symptoms, generally for life. These medications are mainly mood stabilisers (such as lithium), but many also take antipsychotics. These medications come with risks and side effects, which depend on the medication. Side effects can include weight gain, sedation and <a href="https://library.neura.edu.au/bipolar-disorder/physical-features-bipolar-disorder/functional-changes-physical-features-bipolar-disorder/bodily-functions/motor-dysfunction-3/">movement disorders</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1288402621837893632"}"></div></p>
<h2>What happened to the two patients?</h2>
<p>In 2020, Russell Hinton, a private psychiatrist, <a href="https://journals.sagepub.com/doi/abs/10.1177/0004867420912834">described how he treated</a> the first patient. This was a woman who had tried more than a dozen different medications for her bipolar. She had been hospitalised ten times, had gained considerable weight and judged she had no quality of life.</p>
<p>After a poo transplant from her husband, she became symptom-free over the next five years, lost 33 kilograms, required no medication and her career bloomed.</p>
<p>Gordon Parker and colleagues at the University of New South Wales <a href="https://pubmed.ncbi.nlm.nih.gov/35165993/">reported their results</a> with the second patient last month. This was a young man who developed bipolar as a teenager, had tried numerous medications and became progressively intolerant of their side effects.</p>
<p>After a poo transplant, he was able to progressively cease all medications over the next year, and had virtually no mood swings. He also noted an improvement in his anxiety and ADHD (attention deficit hyperactivity disorder).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/adhd-looks-different-in-adults-here-are-4-signs-to-watch-for-178639">ADHD looks different in adults. Here are 4 signs to watch for</a>
</strong>
</em>
</p>
<hr>
<h2>How could this possibly work?</h2>
<p>Trillions of bacteria live in our guts. This so-called gut microbiome has a huge impact on our health in general, not just the health of our brain.</p>
<p>Differences in gut bacteria have been linked to <a href="https://www.nature.com/articles/s41367-019-0011-7">obesity</a>, <a href="https://www.thelancet.com/journals/ebiom/article/PIIS235239641930800-X/fulltext">diabetes</a> and <a href="https://www.gastrojournal.org/article/S0016-5085(19)34649-9/fulltext">irritable bowel syndrome</a>.</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 idea behind poo transplants is to change the gut microbiome. You take poo, with all its micro-organisms, from a healthy person and give it to the one being treated.</p>
<p>You can do this “top down”, for example, by swallowing poo capsules (crapsules), or by delivering poo through a tube inserted into the nose, to the stomach or intestine. </p>
<p>Alternatively, you can insert the poo “bottom up”. You can do this with an enema, a simple, painless procedure in which a syringe transfers the poo into the rectum. Or you can use a colonoscopy, a procedure performed under a general anaesthetic involving inserting a tube higher up into the colon.</p>
<p>Poo transplants are already <a href="https://theconversation.com/poo-transplants-and-probiotics-does-anything-work-to-improve-the-health-of-our-gut-65480">used to treat</a> the often life-threatening gut infection caused by the bacterium <em>Clostridium difficile</em>.</p>
<p>They have also been trialled, with various degrees of success, in people with <a href="https://pubmed.ncbi.nlm.nih.gov/33345703/#:%7E:text=Preliminary%20data%20suggest%20that%20FMT,UC%20being%20the%20most%20compelling">irritable bowel syndrome, ulcerative colitis</a>, <a href="https://www.nature.com/articles/s41467-021-21472-1">HIV</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/32279172/">hepatitis</a>, among other medical conditions.</p>
<p>Side effects from poo transplants <a href="https://pubmed.ncbi.nlm.nih.gov/33345703/#:%7E:text=Preliminary%20data%20suggest%20that%20FMT,UC%20being%20the%20most%20compelling">are rare</a>, and usually relate to the way in which they are given, for example side effects of the anaesthetic from poo transplants delivered by colonoscopy.</p>
<h2>So how about mental health?</h2>
<p>Abnormal gut microbiomes <a href="https://www.nature.com/articles/s41380-022-01456-3">have been linked</a> to bipolar, depression and schizophrenia.</p>
<p>When poo from depressed humans is given to rats, they appear to develop a <a href="https://pubmed.ncbi.nlm.nih.gov/27491067/">rat version of depression</a>. Likewise, when mice are given poo from someone with schizophrenia, they <a href="https://www.science.org/doi/10.1126/sciadv.aau8317">develop a mouse version of schizophrenia</a>.</p>
<p>These are indirect findings. Yet they suggest poo transplants may have the potential to treat some mental health conditions.</p>
<p>So how exactly do bacteria in the gut impact mental health? There are many <a href="https://pubmed.ncbi.nlm.nih.gov/31460832/">different ways</a>, each complicated and interacting with each other. </p>
<p>For example, these bacteria act directly on the gut wall, sending signals to the brain via the vagus nerve. The bacteria also produce large quantities of chemicals (for example, <a href="https://pubmed.ncbi.nlm.nih.gov/31460832/">short-chain fatty acids</a>), which impact virtually all body systems including the immune system. We know brain function relies heavily on immune cells.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/stomach-and-mood-disorders-how-your-gut-may-be-playing-with-your-mind-50847">Stomach and mood disorders: how your gut may be playing with your mind</a>
</strong>
</em>
</p>
<hr>
<h2>Don’t try this at home</h2>
<p>At this stage, any evidence suggesting poo transplants may help people with depression or bipolar is, essentially, anecdotal.</p>
<p>Some people have tried their own version at home, involving poo donors who have not been screened for diseases.</p>
<p>One high-profile example is Dave Hosking from the Australian band Boy & Bear. He used a “<a href="https://www.rollingstone.com/music/music-features/boy-bear-dave-hosking-fecal-transplant-919384/">poo roadie</a>” to provide him with transplants on tour to help manage his depression and anxiety.</p>
<p>We wouldn’t recommend this. Poo transplants should only be carried out under the supervision of medical professionals, using an approved and thoroughly screened poo product.</p>
<p>Poo transplants are <a href="https://www.legislation.gov.au/Details/F2021C01065">tightly regulated in Australia</a>. Donations must be screened for harmful bacteria, fungi, parasites or viruses. Donors must also not have any health condition thought to be associated with gut bacteria, such as an autoimmune condition, cancer or obesity.</p>
<hr>
<p>
<em>
<strong>
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>
</strong>
</em>
</p>
<hr>
<h2>What happens next?</h2>
<p>We need larger, well-designed studies to show poo transplants have a real effect, and any improved symptoms cannot be explained by other factors. </p>
<p>We also need to look for markers in the microbiome that could predict a successful result. If we knew those markers, we could optimise treatment and better measure the results. </p>
<p>The first author’s centre is recruiting <a href="https://foodandmoodcentre.com.au/projects/movingmoods/">people with depression</a> to trial poo transplants. The study will randomise participants to have an enema or placebo enema. If successful, a larger study is planned. </p>
<p>In Canada, there are three such studies under way evaluating poo transplants. These are for <a href="https://pubmed.ncbi.nlm.nih.gov/34261526/">bipolar</a>, <a href="https://clinicaltrials.gov/ct2/show/NCT04805879">depression</a>, with or without <a href="https://clinicaltrials.gov/ct2/show/NCT05174273?cond=fmt&draw=8">irritable bowel syndrome</a>. </p>
<p>Though promising, we cannot conclude at this time whether poo transplants work for bipolar or depression.</p>
<p>Until the results of these studies are in, it’s too early to say if the early results with bipolar can be replicated on a larger scale.</p>
<hr>
<p><em>If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.</em></p><img src="https://counter.theconversation.com/content/177748/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jessica Green is affiliated with:
1. Food & Mood Centre, IMPACT, Deakin University
2. Department of Psychiatry, Peninsula Health
3. Monash Alfred Psychiatry Research Centre, Monash University</span></em></p><p class="fine-print"><em><span>Gordon Parker is affiliated with the Discipline of Psychiatry and Mental Health
School of Clinical Medicine, University of New South Wales
</span></em></p>Two Australians with bipolar have been successfully treated with poo transplants, allowing them to come off, or reduce, their medications. Here’s where the science is up to.Jessica Green, PhD Candidate and Consultant Psychiatrist, Deakin UniversityGordon Parker, Scientia Professor, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1738792022-02-14T13:22:23Z2022-02-14T13:22:23ZWhy do people get diarrhea?<figure><img src="https://images.theconversation.com/files/442542/original/file-20220125-23-5eakbl.jpg?ixlib=rb-1.1.0&rect=0%2C519%2C5058%2C2800&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">No matter its cause, diarrhea is uncomfortable.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/man-holding-toilet-tissue-roll-in-bathroom-royalty-free-image/1249645235">Rapeepong Puttakumwong/Moment via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>Why do people get diarrhea? – A.A.A., age 10, Philadelphia</strong></p>
</blockquote>
<hr>
<p>The digestive system breaks down everything you eat and drink to absorb nutrients and make the energy your body needs. Whatever solids can’t be broken down and used get <a href="https://www.ncbi.nlm.nih.gov/books/NBK539732/">excreted as poop</a>.</p>
<p>Poop comes in many shapes, sizes, colors and consistencies.</p>
<p><a href="https://scholar.google.com/citations?user=mHFFJtUAAAAJ&hl=en&oi=ao">Doctors like me</a> who treat people with digestive issues use what’s called the <a href="https://dx.doi.org/10.1016%2Fj.jpeds.2011.03.002">Bristol stool scale</a> to grade poop texture. It goes from Type 1 – separate hard lumps – to Type 7 – liquid with no solid pieces. The texture of the best poops, Type 4, resembles a mushy banana.</p>
<p>When your <a href="https://blog.katescarlata.com/2021/04/19/common-disorders-associated-with-diarrhea/">poop is loose and watery</a> and comes out that way at least three times a day, you have <a href="https://www.who.int/news-room/fact-sheets/detail/diarrhoeal-disease">diarrhea</a>. It can be uncomfortable and inconvenient, because diarrhea tends to come out quickly and with little warning. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of the seven categories of poop, ranging from overly firm to liquid." src="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?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"></a>
<figcaption>
<span class="caption">The Bristol stool scale puts poop into seven categories that range from the hard pellets of constipation to the splotchy liquid of diarrhea.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/bristol-stool-chart-tool-for-faeces-type-royalty-free-illustration/1250463401">VectorMine/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Beware of bad germs</h2>
<p>By the time food passes out of the stomach, it’s a liquid that travels through the small intestine, where nutrients are absorbed. The leftovers flow into the large intestine, where water is absorbed and poop forms.</p>
<p>When the small intestine or the large intestine can’t do its job, poop will be liquid. </p>
<p>Diarrhea usually occurs because of infections caused by many different <a href="https://www.doi.org/10.4161/gmic.1.1.11036">viruses, bacteria and parasites</a>.</p>
<p>That’s why there are <a href="https://www.epa.gov/dwreginfo/drinking-water-regulations">rules about keeping drinking water clean</a> and <a href="https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/steps-keep-food-safe">food safe</a>. It’s also why you should wash your hands before eating. </p>
<p>These germs cause diarrhea a few different ways. Often, they irritate the intestines, interfering with water absorption. Some germs cause diarrhea by <a href="https://www.mayoclinic.org/diseases-conditions/cholera/symptoms-causes/syc-20355287">releasing chemicals</a> that make the intestines release fluid, making poop even more watery. When these <a href="https://www.cdc.gov/foodsafety/foodborne-germs.html">germs come from food</a>, symptoms can include vomiting, belly pain and diarrhea.</p>
<p>To be sure, not all microbes are bad.</p>
<p>In fact, your <a href="https://doi.org/10.1038/nature11053">digestive system is filled with billions of bacteria</a> and other germs that help you digest food and protect you from bad germs. <a href="https://doi.org/10.2217/17460913.3.5.563">Taking antibiotics for an infection can cause diarrhea</a> by killing off these good bacteria along with the ones that originally made you sick. But people usually get better once they finish prescribed antibiotics and the good bacteria have a chance to recover.</p>
<p>People with diarrhea need to consume lots of liquids to stay hydrated. Water is best. Avoid <a href="https://doi.org/10.1001/archpedi.1985.02140070077039">juice</a> and <a href="https://irritablebowelsyndrome.net/food/no-soda">soda</a>, which can worsen diarrhea. Also refrain from foods that can make your digestive system work harder, like dairy products.</p>
<p><a href="https://www.childrens.com/health-wellness/how-to-treat-diarrhea-in-kids">Eating sweet potatoes, oats, beets</a> and other high-fiber foods may help firm up loose poops. Never take a medication, even if doesn’t require a prescription, for diarrhea without asking a doctor first. </p>
<h2>Many other causes</h2>
<p>There are many other causes of diarrhea.</p>
<p>Some people are born with or develop conditions over the course of their lives that can cause diarrhea.</p>
<p>A common example is <a href="http://dx.doi.org/10.1136/gutjnl-2019-318404">lactose intolerance</a>. Lactose is a sugar that is in milk that requires a <a href="https://www.britannica.com/science/lactase">special enzyme, called lactase</a>, to digest it in the small intestine. There are people who have little, or even none, of this enzyme in their small intestine. As a result, lactose travels into their large intestine without being broken down and absorbed – leaving poop very runny.</p>
<p><a href="https://doi.org/10.3389/fped.2018.00350">Celiac disease</a> can also trigger diarrhea. People with it have <a href="https://www.health.harvard.edu/healthbeat/getting-out-the-gluten">trouble digesting gluten</a>, a protein found in wheat and additional grains. For people with celiac disease, eating gluten can damage the small intestine by activating their own immune system. This damage is reversible through a gluten-free diet, but diarrhea may continue until the small intestine heals and can do its job.</p>
<p>Others have <a href="https://doi.org/10.3389/fmed.2017.00261">digestive system allergies</a>. They need to avoid eating specific foods to prevent diarrhea and other symptoms. </p>
<p>Some medications make you poop more often.</p>
<p>There are also medical conditions, like <a href="https://doi.org/10.1053/j.gastro.2021.04.063">inflammatory bowel disease</a>, such as <a href="https://www.mayoclinic.org/diseases-conditions/crohns-disease/symptoms-causes/syc-20353304">Crohn’s disease</a> and <a href="https://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/symptoms-causes/syc-20353326">ulcerative colitis</a>, in which the small intestine, large intestine or both become inflamed over a period of time.</p>
<p>Even your brain can play a role: Experiencing anxiety or <a href="https://www.healthline.com/health/anxiety-diarrhea">getting stressed out</a> can bring about loose poops. Some conditions, like <a href="https://doi.org/10.14309/ajg.0000000000001036">irritable bowel syndrome</a>, where the brain and the intestines do not communicate well with each other, can lead to belly pain and diarrhea, particularly amid stress. </p>
<p><a href="https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/diarrhea/art-20044799">Certain cancers</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6867674/">some tumors</a> can cause diarrhea too. </p>
<p>Finally, for some people, eating spicy or fatty food or consuming artificial sweeteners or <a href="https://www.healthline.com/health/foods-that-cause-diarrhea#food-and-diarrhea">large amounts of caffeine</a> can result in diarrhea. </p>
<p>Even if you find it icky, I recommend you pay attention to your poop. If you’re having diarrhea all the time, rather than occasionally, you may need to see a doctor.</p>
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<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/173879/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hannibal Person 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>Poop comes in many shapes, sizes and textures. The kind that’s too runny might be the result of wayward germs, Crohn’s disease or lactose intolerance.Hannibal Person, Assistant Professor of Gastroenterology and Hepatology, School of Medicine, University of WashingtonLicensed 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>
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<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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<em>
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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>
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<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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<p>
<em>
<strong>
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>
<figure class="align-center ">
<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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<em>
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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/1703662021-11-11T18:58:40Z2021-11-11T18:58:40ZGut bacteria don’t cause autism. Autistic kids’ microbiome differences are due to picky eating<figure><img src="https://images.theconversation.com/files/431254/original/file-20211110-17-t6tf1u.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/spoon-fork-on-empty-plate-778735972">Shutterstock</a></span></figcaption></figure><p>There has been much speculation that the community of bacteria living in the gut – known as the microbiome – may be different among people on the autism spectrum than the wider population. This has led some researchers and clinicians to speculate that gut bacteria could cause autism.</p>
<p>But our new research, <a href="https://www.cell.com/cell/fulltext/S0092-8674(21)01231-9">published today</a> in the journal Cell, turns this theory on its head. </p>
<p>Rather than differences in gut bacteria influencing brain development, our research suggests changes in gut bacteria are driven by restricted diets, or “picky eating”. </p>
<p>Restricted diets are more common among children with autism because of their sensory sensitivities and restricted and repetitive interests. Some may have strong preferences for a select few foods, while others find some flavours, smells or textures unpleasant or off-putting. </p>
<h2>What’s the theory?</h2>
<p>You may have heard claims the microbiome is related to autism: it may have a “causal” role, or microbiome “therapies” <a href="https://www.nature.com/articles/s41598-019-42183-0">can alter autistic behaviours</a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-causes-autism-what-we-know-dont-know-and-suspect-53977">What causes autism? What we know, don’t know and suspect</a>
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<p>Interest in the autism gut microbiome first came from observations people on the autism spectrum are more likely to experience gut problems, such as constipation and diarrhoea. </p>
<p>Further <a href="https://link.springer.com/article/10.1186/s13099-020-0346-1">studies</a> seemed to suggest children on the autism spectrum had different combinations of bacteria living in their gut.</p>
<figure class="align-center ">
<img alt="Child sits on the end of a bed, clutching their stomach." src="https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431259/original/file-20211110-27-1sjgqag.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">Autistic children are more likely to have restricted diets.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/abdominal-pain-preschool-child-poisoning-children-1783437671">Shutterstock</a></span>
</figcaption>
</figure>
<p>These intriguing relationships inspired studies of mice and rats, some of which indicated the <a href="https://pubmed.ncbi.nlm.nih.gov/31150625/">microbiome may cause differences in behaviour</a>. </p>
<p>But the excitement has been misguided. </p>
<h2>Assessing the evidence</h2>
<p>Weighing up all the findings, the evidence linking the microbiome to autism is <a href="https://www.spectrumnews.org/news/despite-flurry-of-findings-doubts-dog-gut-microbes-role-in-autism/">highly inconsistent and many studies have significant problems</a> with their scientific design. </p>
<p>There are also problems in relating mouse studies to humans, because autism does not exist in mice. </p>
<p>Despite the uncertainty in the science, the hype around the microbiome and autism has continued to gather momentum.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1134474617492578305"}"></div></p>
<p>Out of this momentum emerged speculative therapies claiming to support children with autism by altering the microbiome, including faecal microbiota transfers and diet therapies. </p>
<p>These “therapies” were long on hope but short on evidence for efficacy and safety, and come with their own risks and substantial costs.</p>
<h2>What our study did</h2>
<p>We worked with the <a href="https://www.autismcrc.com.au/biobank">Australian Autism Biobank</a>, which includes extensive clinical and biological data from children on the autism spectrum and their families, as well as the <a href="https://qbi.uq.edu.au/QTABproject">Queensland Twin Adolescent Brain Project</a>. </p>
<p>We compared microbial DNA from stool samples of 99 children on the autism spectrum to two groups of non-autistic children: 51 of their siblings and 97 unrelated children. </p>
<p>We also looked at clinical, family and lifestyle information, including about the child’s diet, for a comprehensive, broad look at factors that may contribute to the their microbiome. </p>
<h2>What we found</h2>
<p>We found no evidence for a relationship between autism and measures of the microbiome as a whole, or with microbiome diversity. </p>
<p>Only one bacterial species out of more than 600 showed an association with autism. We found no evidence for other bacterial groups that have previously been reported in autism (for example, <em>Prevotella</em>). </p>
<p>Instead, we found children on the autism spectrum were more likely to be “picky eaters” – consistent with <a href="https://pubmed.ncbi.nlm.nih.gov/15449518/">reports</a> <a href="https://pubmed.ncbi.nlm.nih.gov/23371510/">from</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936505/">earlier</a> <a href="https://www.frontiersin.org/articles/10.3389/fpsyt.2021.668297/full">studies</a> – and this was related to particular traits associated with autism, such as restricted interests and sensory sensitivity.</p>
<p>We also found pickier eaters tended to have a less diverse microbiome, and runnier (more diarrhoea-like) stool. We’ve also known for some time children on the autism spectrum are more likely to have <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0033224">gastrointestinal</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3981895/">issues</a> such as constipation, diarrhoea and abdominal pain.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431388/original/file-20211110-19-16o7kq4.png?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">Changes in gut bacteria are driven by restricted diets.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The genetic information told a similar story: autism and restricted interests corresponded to a less-diverse diet, but not directly with the microbiome. </p>
<p>These genetic data are critical, because they rule out other environmental factors that may have influenced the findings.</p>
<p>Overall, our results did not support the popular view that gut microbes cause autism. </p>
<p>What we propose instead is strikingly simple: autism-related traits and preferences are associated with less-diverse diet, leading to a less-diverse microbiome and runnier stool.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=141&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=141&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431407/original/file-20211111-5078-awhy25.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=141&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here’s how our study maps the effect of diet.</span>
</figcaption>
</figure>
<h2>What do our findings mean?</h2>
<p>Our findings have important implications for the autism community. </p>
<p>First, microbiome interventions for autism, such as faecal microbiota transplants, should be viewed with caution. Our findings suggest they are unlikely to be effective and <a href="https://www.fda.gov/safety/medical-product-safety-information/fecal-microbiota-transplantation-safety-alert-risk-serious-adverse-events-likely-due-transmission">may do more harm than good</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/these-4-diets-are-trending-we-looked-at-the-science-or-lack-of-it-behind-each-one-136045">These 4 diets are trending. We looked at the science (or lack of it) behind each one</a>
</strong>
</em>
</p>
<hr>
<p>Our study also draws attention to the importance of diet for children on the autism spectrum. Poor diet in children and young people is a <a href="https://www.aihw.gov.au/reports/food-nutrition/poor-diet/contents/poor-diet-in-children">major public health concern in Australia</a>, with important implications for their well-being, development and health conditions such as obesity. </p>
<p>We need to do more to support families at mealtimes, in particular for families with autistic children, rather than resorting to fad “therapies” that may do more harm than good.</p><img src="https://counter.theconversation.com/content/170366/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chloe Yap receives funding from the University of Queensland, the Cooperative Research Centre for Living with Autism (Autism CRC), and the Australian-American Fulbright Commission. </span></em></p><p class="fine-print"><em><span>Andrew Whitehouse receives funding from the National Health and Medical Research Council, the Australian Research Council, and the Autism CRC.</span></em></p><p class="fine-print"><em><span>Jake Gratten receives funding from the Australian National Health and Medical Research Council (NHMRC) and the Cooperative Research Centre for Living with Autism (Autism CRC). </span></em></p>New research dispels the myth that gut bacteria causes autism. Rather, changes in the gut bacteria of some people with autism are driven by restricted diets or ‘picky eating’.Chloe Yap, MD-PhD candidate, The University of QueenslandAndrew Whitehouse, Bennett Chair of Autism, Telethon Kids Institute, The University of Western AustraliaJake Gratten, Senior Research Fellow, Mater Research Institute - University of Queensland, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1554722021-03-12T01:47:15Z2021-03-12T01:47:15ZBoosting your ‘gut health’ sounds great. But this wellness trend is vague and often misunderstood<figure><img src="https://images.theconversation.com/files/386867/original/file-20210228-13-69nmka.jpg?ixlib=rb-1.1.0&rect=0%2C1%2C998%2C663&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/woman-hands-making-heart-shape-on-1414143233">from www.shutterstock.com</a></span></figcaption></figure><p>If you walk down the supermarket aisle, you may be tempted with foods <a href="https://www.forbes.com/sites/daveknox/2020/07/16/why-gut-health-is-the-next-big-wellness-trend/?sh=90d972919783">marketed as</a> being good for your gut. Then there are the multiple <a href="https://www.healthline.com/health/food-nutrition/best-gut-health-blogs#1">health blogs</a> about improving, supporting or maintaining your “gut health”.</p>
<p>But what does “gut health” mean? Is it the absence of disease? Is it no bloating? Or is it something else entirely? And how strong is the evidence “gut health” products actually make a difference?</p>
<p>As we explain in our article <a href="https://www.thelancet.com/journals/langas/article/PIIS2468-1253(21)00071-6/fulltext">just published</a> in the journal <a href="https://www.thelancet.com/journals/langas/home">Lancet Gastroenterology & Hepatology</a>, even researchers have not quite nailed a definition. Here’s what we know so far.</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>What does the science say?</h2>
<p>We know the gut is important for our overall health and well-being. And when we say “gut”, we usually mean the large intestine, the region of the gastrointestinal tract where most of our gut microbiome lives. </p>
<p>Our gut microbiome is our gut’s resident microbes. And evidence is emerging this <a href="https://www.bmj.com/content/361/bmj.k2179">affects</a> everything from how our body processes sugar in our diet, to our risk of cancer, depression and dementia.</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">Remind me again, what is the microbiome?</span></figcaption>
</figure>
<p>But there’s no clear agreement on what “gut health” actually means. Researchers don’t use the term in the medical literature very much. When <a href="https://www.nature.com/articles/ejcn200964">they do</a>, they seem to refer to no:</p>
<ul>
<li><p>unwanted gastrointestinal symptoms (such as pain or diarrhoea)</p></li>
<li><p>disease (such as Crohn’s disease or colon cancer), or</p></li>
<li><p>negative gut features (such as inflammation, a deficiency of certain molecules or an imbalance in the microbiome), which are almost impossible to precisely diagnose.</p></li>
</ul>
<p>Nowhere do researchers or gastroenterologists (doctors who specialise in the gut) mention any aesthetic perks, such as a smooth, flat belly or glowing skin, despite what <a href="https://cultivatebeauty.com.au/gut-health-glowing-skin/">magazine articles</a> might suggest.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-men-really-take-longer-to-poo-152233">Do men really take longer to poo?</a>
</strong>
</em>
</p>
<hr>
<h2>So, what’s the problem?</h2>
<p>There are two main problems with products or <a href="https://www.eatthis.com/foods-gut-health/">lists of foods</a> that claim to be good for “gut health”.</p>
<p>First, such claims are not backed by strong scientific evidence. Second, these claims are simplistic.</p>
<p>While a healthy diet is undoubtedly an essential contributor to good health, including of the gastrointestinal system, it’s dietary patterns and overall habits, not individual foods, that shift the dial.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/these-5-foods-are-claimed-to-improve-our-health-but-the-amount-wed-need-to-consume-to-benefit-is-a-lot-116730">These 5 foods are claimed to improve our health. But the amount we'd need to consume to benefit is... a lot</a>
</strong>
</em>
</p>
<hr>
<h2>Let’s take fibre as an example</h2>
<p>Fibre is one dietary component heralded as a <a href="https://loveyourgut.com/all-entries/hero-ingredients-for-good-gut-health/">gut health hero</a>. Indeed, there is compelling evidence showing <a href="https://www.nature.com/articles/s41575-020-00375-4">health benefits of a high-fibre diet</a>, for the gastrointestinal tract, and also more broadly (for instance, a reduced risk of heart disease and diabetes).</p>
<p>Yet most people in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124841/">Western</a> <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/943114/NDNS_UK_Y9-11_report.pdf">countries</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6163727/">do not eat enough dietary fibre</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bowl of high-fibre cereal" src="https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386622/original/file-20210226-15-177l4lh.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 bowl of high-fibre breakfast cereal alone is unlikely to help your ‘gut health’ if your overall diet or lifestyle is a problem.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wheat-bran-breakfast-cereal-no-milk-371849272">www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>However, the little-told story is foods contain multiple types of dietary fibre, each with <a href="https://www.nature.com/articles/s41575-020-00375-4">different effects</a> on gut function (and its microbiome).</p>
<p>We don’t know if all types of fibre are essential or beneficial. At least in animals, too much of certain fibres might <a href="https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/nutrition-and-gut-health-the-impact-of-specific-dietary-components-its-not-just-fiveaday/695D2CD23097CA8D98C814037C9CADA1">affect the large intestine</a>, causing inflammatory disease. </p>
<p>So yes, eat high-fibre foods <a href="https://www.gutmicrobiotaforhealth.com/how-to-eat-for-a-diverse-microbiota/">(including</a> wholegrain cereals, fruit, vegetables, legumes and nuts). But do so as part of a varied diet, not by overloading on just one or two foods or commercial products claiming to improve your “gut health”.</p>
<h2>We are all individuals</h2>
<p>The optimal diet for your gut as well as your overall health is likely to be highly individual. What is best for one person may not be so for the next. </p>
<p>Large human studies show the gut microbiome may be the major driver of this <a href="https://www.cell.com/fulltext/S0092-8674(15)01481-6">individuality</a>, responsible for some of the variability in how different people metabolise food.</p>
<p>However, as we have written about <a href="https://theconversation.com/should-i-test-my-gut-microbes-to-improve-my-health-131216">before</a>, it isn’t yet possible to define the perfect microbiome, or how to get one. What is clear is that any one product is unlikely to achieve this anyway.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/should-i-test-my-gut-microbes-to-improve-my-health-131216">Should I test my gut microbes to improve my health?</a>
</strong>
</em>
</p>
<hr>
<h2>So where does this leave us?</h2>
<p>If we accept the concept of “gut health” has many nuances, what next?</p>
<p>There is good evidence the health of the gastrointestinal tract and its microbiome are <a href="https://www.bmj.com/content/361/bmj.k2179">important for overall health</a>, and certainly the absence of pain and disease boosts our well-being. </p>
<p>But rather than focusing on one food, the evidence for what’s best for our gut tells us we’d be better off looking at improving our overall diet. <a href="https://www.eatforhealth.gov.au/guidelines">National healthy eating guidelines</a> universally include advice to eat a variety of foods, including those high in fibre, and to avoid excessive alcohol. </p>
<p>General principles of a healthy lifestyle apply too: avoid substance abuse (including smoking, off-label prescription drugs and illicit drugs), exercise regularly, take care of your mental well-being and manage your stress.</p>
<p>All these combined are likely to be more helpful for gut health than the latest superfood or boxed cereal.</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>
<img src="https://counter.theconversation.com/content/155472/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Loughman receives funding from The Jack Brockhoff Foundation and Deakin University.</span></em></p><p class="fine-print"><em><span>Heidi Staudacher receives fellowship funding from Deakin University and has received non-financial and financial support from CD investments VSL pharmaceuticals. </span></em></p>Rather than focusing on single foods for ‘gut health’, we’re better off having a balanced diet and a healthy lifestyle.Amy Loughman, Senior Research Fellow, Deakin UniversityHeidi Staudacher, Postdoctoral Research Fellow, Food & Mood Centre, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1522332021-01-27T01:10:59Z2021-01-27T01:10:59ZDo men really take longer to poo?<figure><img src="https://images.theconversation.com/files/377953/original/file-20210111-15-ruzndd.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1000%2C667&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/close-man-toilet-using-phone-619346291">from www.shutterstock.com</a></span></figcaption></figure><p>There’s a common assumption men take longer than women to poo. People say so on <a href="https://twitter.com/trenduso/status/1100968885203931136">Twitter</a>, in <a href="https://www.sammichespsychmeds.com/men-bathroom-memes/">memes</a>, and <a href="https://www.youtube.com/watch?v=nLcEU6ahlOI">elsewhere</a> <a href="https://www.livescience.com/why-men-take-longer-to-poop.html">online</a>. But is that right? What could explain it? And if some people are really taking longer, is that a problem?</p>
<p>As we sift through the evidence, it’s important to remember pooing may involve time spent sitting on the toilet and the defaecation process itself.</p>
<p>And there may be differences between men and women in these separate aspects of going to the toilet. But the evidence for these differences isn’t always as strong as we’d like.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-we-have-to-poo-every-day-we-asked-five-experts-98701">Do we have to poo every day? We asked five experts</a>
</strong>
</em>
</p>
<hr>
<h2>Men may spend longer sitting on the toilet</h2>
<p>Men do appear to spend more time sitting on the toilet. An <a href="https://www.dailymail.co.uk/femail/article-2641550/Britons-favourite-loo-terature-revealed-Sports-biographies-erotic-magazines-bathroom-reading-material-poll.html">online survey</a> by a bathroom retailer suggested men spend up to 14 minutes a day compared with women, who spend almost eight minutes a day. But this survey doesn’t have the rigour of a well-designed scientific study.</p>
<p>Would there be any physiological reason to explain why men spend longer on the toilet? Well, the evidence actually suggests the opposite.</p>
<p>We know it <a href="https://www.tandfonline.com/doi/abs/10.1080/00365520310000410">takes longer</a> for food to travel through the intestines in women than in men. Women are also <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175559/">more likely to suffer</a> from constipation related to irritable bowel syndrome than men. So, you’d expect women to take longer to defaecate, from the start of the bowel motion to expulsion.</p>
<p>But this is <a href="https://pubmed.ncbi.nlm.nih.gov/12870773/">not the case</a> even if you take into account differences in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986479/">fibre intake</a> between men and women.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-what-is-irritable-bowel-syndrome-and-what-can-i-do-about-it-102579">Explainer: what is irritable bowel syndrome and what can I do about it?</a>
</strong>
</em>
</p>
<hr>
<p>Instead, how long it takes someone to poo (the defaecation time) is <a href="https://pubmed.ncbi.nlm.nih.gov/28470247/">heavily influenced</a> by the mucus lining the large bowel. This mucus makes the bowel slippery and easier for the stools to be expelled. But there’s no evidence this mucus lining is different in men and women. </p>
<p>One thing we do know, however, is mammals from elephants to mice have a similar defaecation time, <a href="https://pubs.rsc.org/en/content/articlelanding/2017/sm/c6sm02795d#!divAbstract">around 12 seconds</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1100968885203931136"}"></div></p>
<p>For humans, it’s slightly longer, but still quick. In <a href="https://pubmed.ncbi.nlm.nih.gov/12870773/">one study</a> it took healthy adults an average two minutes when sitting, but only 51 seconds when squatting. Again, there were no differences in defaecation time between men and women, whether sitting or squatting. </p>
<p>If there’s no strong evidence one way or the other to explain any gender differences in how long it takes to poo, what’s going on? For that, we need to look at the total time spent on the toilet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/whats-the-best-way-to-go-to-the-toilet-squatting-or-sitting-63991">What's the best way to go to the toilet – squatting or sitting?</a>
</strong>
</em>
</p>
<hr>
<h2>Why do people spend so long on the toilet?</h2>
<p>What I call the “toilet sitting time” is the time of defaecation itself and the time allocated to other activities sitting on the toilet. For most people, the time spent just sitting, aside from defaecating, accounts for most of their time there.</p>
<p>So what are people doing? Mainly reading. And it seems men are <a href="http://news.bbc.co.uk/2/hi/health/1230115.stm">more likely</a> to read on the toilet than women.</p>
<p>For instance, a <a href="https://pubmed.ncbi.nlm.nih.gov/19019015/">study</a> of almost 500 adults in Israel found almost two-thirds (64%) of men regularly read on the toilet compared with 41% of women. The longer people spent on the toilet, the more likely they were to be reading. However, in the decade or more since this study was conducted, you’d expect adults would be more likely to be reading or playing games on their mobile phones rather than reading paper books.</p>
<p>People might also be sitting longer on the toilet for some temporary relief from the stresses of life.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Meme about men avoiding parenting responsibilities by sitting on the toilet for longer" src="https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/380091/original/file-20210121-19-q4weg1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sometimes, people just need time to themselves.</span>
<span class="attribution"><a class="source" href="https://www.sammichespsychmeds.com/men-bathroom-memes/">Ramblin Mama</a></span>
</figcaption>
</figure>
<p>One <a href="https://www.dailymail.co.uk/femail/article-2641550/Britons-favourite-loo-terature-revealed-Sports-biographies-erotic-magazines-bathroom-reading-material-poll.html">poll</a> found 56% of people find sitting on the toilet relaxing, and 39% a good opportunity to have “some time alone”. Another <a href="https://www.independent.co.uk/life-style/bathrooms-shower-washing-habits-poll-a8988626.html">online survey</a> revealed one in six people reported going to the toilet for “peace and quiet”. Although these are not scientific studies, they offer useful insights into a social phenomenon.</p>
<p>Then there can be medical reasons for a prolonged defaecation time, and consequently a lengthier time sitting on the toilet. </p>
<p>An anal fissure (a tear or crack in the lining of the anus) can make defaecation a painful and lengthy process. These fissures are <a href="http://eknygos.lsmuni.lt/springer/526/178-191.pdf">just as common</a> in men as in women. </p>
<p>And <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306148/">obstructive defaecation</a>, where people cannot empty the rectum properly, is a common cause of chronic constipation. This is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030249/">more common</a> in middle-aged women. </p>
<h2>Are there any harms from spending too long on the loo?</h2>
<p>In a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236649/">Turkish study</a>, spending more than five minutes on the toilet was associated with haemorrhoids and anal fissures. Another study from <a href="https://pubmed.ncbi.nlm.nih.gov/31996480/">Italy</a> noted the longer the time people spent on the toilet, the more severe their haemorrhoids.</p>
<p><a href="http://www.annalsgastro.gr/files/journals/1/earlyview/2019/ev-01-2019-19-AG4360-0355.pdf">One theory</a> behind this is prolonged sitting increases pressure inside the abdomen. This leads to less blood flow into the veins of the rectum when passing a bowel motion, and ultimately to blood pooling in the vascular cushions of the anus. This makes haemorrhoids more likely to develop. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-why-do-people-get-haemorrhoids-and-how-do-you-get-rid-of-them-94820">Explainer: why do people get haemorrhoids and how do you get rid of them?</a>
</strong>
</em>
</p>
<hr>
<h2>What can we do about this?</h2>
<p>In addition to the usual advice about increasing the amount of fibre in your diet and ensuring you drink enough water, it would be sensible to limit the amount of time spent on the toilet.</p>
<p>Different researchers recommend a <a href="https://pubmed.ncbi.nlm.nih.gov/28150480/">different</a> <a href="https://pubmed.ncbi.nlm.nih.gov/27723447/">upper limit</a>. But I <a href="https://pubmed.ncbi.nlm.nih.gov/30346317/">and others</a> recommend the SEN approach:</p>
<ul>
<li><p><strong>S</strong>ix minute toilet sitting time maximum</p></li>
<li><p><strong>E</strong>nough fibre (eating more fruit and vegetables, and eating wholegrains)</p></li>
<li><p><strong>N</strong>o straining during defaecation. </p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-what-causes-constipation-114290">Health Check: what causes constipation?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/152233/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vincent Ho 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>If you believe the memes, men spend ages in the toilet. But they’re not always pooing. Here’s what they’re really doing.Vincent Ho, Senior Lecturer and clinical academic gastroenterologist, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1516732020-12-20T21:12:02Z2020-12-20T21:12:02ZHow to prepare and protect your gut health over Christmas and the silly season<figure><img src="https://images.theconversation.com/files/373754/original/file-20201209-21-15cg2t2.jpg?ixlib=rb-1.1.0&rect=0%2C6%2C4493%2C2984&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>It’s that time of year again, with Christmas parties, end-of-year get-togethers and holiday catch-ups on the horizon for many of us — all COVID-safe, of course. All that party food and takeaway, however, can have consequences for your gut health.</p>
<p>Gut health matters. Your gut is a crucial part your immune system. In fact, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515351/">70%</a> of your entire immune system sits around your gut, and an important part of that is what’s known as the gut-associated lymphoid tissue (GALT), which houses a host of immune cells in your gut. </p>
<p>Good gut health means looking after your gut microbiome — the bacteria, fungi, viruses and tiny organisms that live inside you and help break down your food — but also the cells and function of your gastrointestinal system.</p>
<p>We know gut health can affect <a href="https://theconversation.com/stomach-and-mood-disorders-how-your-gut-may-be-playing-with-your-mind-50847">mood</a>, thanks to what’s known as the gut-brain axis. But there’s also a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7509439/">gut-lung axis</a> and a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165386/">gut-liver</a> axis, meaning what happens in your gut can affect your <a href="https://theconversation.com/food-as-medicine-how-what-you-eat-shapes-the-health-of-your-lungs-73450">respiratory system</a> or liver, too.</p>
<p>Here’s what you can do to bolster your gut microbiome in the coming weeks and months.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YB-8JEo_0bI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/gut-health-does-exercise-change-your-microbiome-140003">Gut health: does exercise change your microbiome?</a>
</strong>
</em>
</p>
<hr>
<h2>How do silly season indulgences affect our gut health?</h2>
<p>You can change your gut microbiome within a couple of days by <a href="https://pubmed.ncbi.nlm.nih.gov/24336217/">changing your diet</a>. And over a longer period of time, such as the Christmas-New Year season, your diet pattern can change significantly, often without you really noticing.</p>
<p>That means we may be changing the organisms that make up our microbiome during this time. Whatever you put in will favour certain bacteria in your microbiome over others.</p>
<p>We know fatty, sugary foods promote bacteria that are not as beneficial for gut health. And if you indulge over days or weeks, you are pushing your microbiome towards an imbalance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&rect=15%2C15%2C5160%2C3430&q=45&auto=format&w=1000&fit=clip"><img alt="A group of friends clink drinks while wearing Christmas gear." src="https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&rect=15%2C15%2C5160%2C3430&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373516/original/file-20201208-21-zahfs0.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">For many of us, Christmas is a time of indulgence.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Is there anything I can do to prepare my gut health for the coming onslaught?</h2>
<p>Yes! If your gut is healthy to begin with, it will take more to knock it out of whack. Prepare yourself now by making choices that feed the beneficial organisms in your gut microbiome and enhance gut health. </p>
<p>That means:</p>
<ul>
<li><p>eating <a href="https://www.monash.edu/medicine/ccs/gastroenterology/prebiotic/faq">prebiotic foods</a> such as jerusalem artichokes, garlic, onions and a variety of grains and inulin-enhanced yoghurts (inulin is a prebiotic carbohydrate shown to have broad benefits to gut health)</p></li>
<li><p>eating <a href="https://www.youtube.com/watch?v=NI3KtR3LoqM">resistant starches</a>, which are starches that pass undigested through the small intestine and feed the bacteria in the large intestine. That includes grainy wholemeal bread, legumes such as beans and lentils, firm bananas, starchy vegetables like potatoes and some pasta and rice. The trick to increasing resistant starches in potato, pasta and rice is to cook them but <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12143">eat</a> them <a href="https://pubmed.ncbi.nlm.nih.gov/21831780/">cold</a>. So consider serving a cold potato or pasta salad over Christmas</p></li>
<li><p>choosing fresh, unprocessed fruits and vegetables</p></li>
<li><p>steering clear of added sugar where possible. Excessive amounts of added sugar (or fruit sugar from high consumption of fruit) flows quickly to the large intestine, where it gets gobbled up by bacteria. That can cause higher gas production, diarrhoea and potentially upset the balance of the microbiome</p></li>
<li><p>remembering that if you increase the amount of fibre in your diet (or via a supplement), you’ll need to drink more water — or you can get constipated.</p></li>
</ul>
<p>For inspiration on how to increase resistant starch in your diet for improved gut health, you might consider checking out a <a href="https://www.ecu.edu.au/schools/medical-and-health-sciences/our-research/systems-and-intervention-research-centre-for-health/nutrition-and-dietetics-research-group/projects/gut-feeling-mindful-menus-for-the-microbiome">cookbook</a> I coauthored (all proceeds fund research and I have no personal interest).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373542/original/file-20201208-19-4m444t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&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 gut health is hard won and easily lost.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>What can I do to limit the damage?</h2>
<p>If Christmas and New Year means a higher intake of red meat or processed meat for you, remember some studies have shown that diets higher red meat can introduce DNA damage in the colon, which makes you <a href="https://www.cancer.org.au/cancer-information/causes-and-prevention/diet-and-exercise/meat-and-cancer-risk">more susceptible to colorectal cancer</a>.</p>
<p>The good news is other <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4531472/">research</a> suggests if you include a certain amount of resistant starch in a higher red meat diet, you can reduce or even eliminate that damage. So consider a helping of cold potato salad along with a steak or sausage from the barbie.</p>
<p>Don’t forget to exercise over your Christmas break. Even going for a brisk walk can get things moving and keep your bowel movements regular, which helps improve your gut health.</p>
<p>Have a look at the <a href="https://www.eatforhealth.gov.au/guidelines/australian-guide-healthy-eating">Australian Guide to Healthy Eating</a> and remember what foods are in the “sometimes” category. Try to keep track of whether you really are only having these foods “sometimes” or if you have slipped into a habit of having them much more frequently. </p>
<p>The best and easiest way to check your gut health is to use the Bristol stool chart. If you’re hitting around a 4, you should be good.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An image of the Bristol stool chart" src="https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374096/original/file-20201210-23-2zfeu2.jpg?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"></a>
<figcaption>
<span class="caption">If you’re hitting around a 4, you should be good.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Remember, there are no quick fixes. Your gut health is like a garden or an ecosystem. If you want the good plants to grow, you need to tend to them — otherwise, the weeds can take over. </p>
<p>I know you’re probably sick of hearing the basics — eat fruits and vegetables, exercise and don’t make the treats too frequent — but the fact is good gut health is hard won and easily lost. It’s worth putting in the effort.</p>
<p>A preventative mindset helps. If you do the right thing most of the time and indulge just now and then, your gut health will be OK in the end.</p><img src="https://counter.theconversation.com/content/151673/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Claus T. Christophersen receives funding from NHMRC and WA Department of Health. He is a co-author of The Gut Feeling Cookbook linked in this article – all proceeds from sales of this cookbook go directly back into supporting our research, no personal financial interest.</span></em></p>If your gut is healthy to begin with, it will take more to knock it out of whack. Prepare yourself now by making food choices that feed the microbiome and enhance gut health.Claus T. Christophersen, Senior Lecturer, Edith Cowan UniversityLicensed 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/1400032020-06-16T12:39:28Z2020-06-16T12:39:28ZGut health: does exercise change your microbiome?<figure><img src="https://images.theconversation.com/files/342147/original/file-20200616-23231-1nbj2sh.jpg?ixlib=rb-1.1.0&rect=16%2C8%2C5590%2C3724&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Exercise is good for your gut bacteria too.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-mature-adults-working-out-fitness-180934166">CREATISTA/ Shutterstock</a></span></figcaption></figure><p>The diverse, non-human life forms that live in our guts – known as our microbiome – are crucial to our health. A disrupted balance of these contribute to a range of <a href="https://pubmed.ncbi.nlm.nih.gov/29899036/">disorders and diseases</a>, including obesity, diabetes, inflammatory bowel disease. It could even affect our mental health. </p>
<p>It’s well known that the microbes living in our guts are altered through <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682904/">diet</a>. For example, including <a href="https://pubmed.ncbi.nlm.nih.gov/28165863/">dietary fibre</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/31136662/">dairy products</a> in our diets encourages the growth of beneficial bacteria. But mounting evidence suggests that exercise can also <a href="https://pubmed.ncbi.nlm.nih.gov/30883471/">modify the types of bacteria</a> that reside within our guts. </p>
<p>One study found exercise <a href="https://pubmed.ncbi.nlm.nih.gov/18256465/">promotes the growth of bacteria</a> which produce the fatty acid, <a href="https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/butyrate">butyrate</a>. Butyrate can promote repair of the gut lining and reduce inflammation, therefore potentially <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3070119/">preventing diseases</a> such as inflammatory bowel disease and insulin resistance, which leads to diabetes. Exercise-induced shifts in the gut microbiota can also guard against obesity and improve metabolic function.</p>
<p>Microbiome changes can even be seen following quite modest exercise regimes. One study found that women who performed at least <a href="https://pubmed.ncbi.nlm.nih.gov/28187199/">three hours of light exercise</a> – such as a brisk walk or swim – per week had increased levels of <em>Faecalibacterium prausnitzii</em>, <em>Roseburia hominis</em>, and <em>Akkermansia muciniphila</em> compared with sedentary individuals. </p>
<p><a href="https://www.nature.com/articles/ismej2016176"><em>F. prausitzii</em></a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622956/"><em>R. hominis</em></a> reduce inflammation, while <a href="https://gut.bmj.com/content/65/3/426.long"><em>A. muciniphila</em></a> has been associated with a lean body mass index (BMI) and improved metabolic health. This means that these microbiome changes are likely to be beneficial to overall health. </p>
<p>But it appears that the type of exercise also has <a href="https://pubmed.ncbi.nlm.nih.gov/25678701/">different effects</a> on the changes seen in the gut microbiota. Studies of rodents found that being forced to run on a wheel induced different microbiota changes compared to moderate exercise done when the mouse wanted to. There’s some evidence that the same is true <a href="https://pubmed.ncbi.nlm.nih.gov/27924137/">in humans</a>.</p>
<p>Athletes also have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7218537/">very different microbiota profiles</a> compared to sedentary people of similar age and sex. Athletes had more diverse microflora, and a higher abundance of the three bacterial species mentioned above.</p>
<p>However, it still remains to be definitively proven that exercise can act independently of diet in making these changes. People who exercise may be more likely to also eat a healthier diet, so separating the two factors apart can be somewhat difficult. </p>
<h2>Diet versus exercise</h2>
<p>Animal studies, mainly on rodents, can shed some light on this conundrum as their diet is easily controlled. In mice, diet and exercise appear to induce <a href="https://pubmed.ncbi.nlm.nih.gov/25217888">very different changes</a> in the microbiota. Some changes caused by a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2770164/">high fat diet</a> – including an increase in <em>Firmicutes</em> and <em>Proteobacteria</em>, which are linked to type two diabetes and obesity – can be reversed by exercise. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=441&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=441&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342149/original/file-20200616-23247-1r63omn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=441&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rodent studies are useful as their diets are easily controlled.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/genetic-obese-mouse-black-healthy-control-716011576">Janson George/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Other studies suggest that exercise-induced changes in the microbiota can be brought about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4987217/">independent of dietary intake</a> – though other studies show <a href="https://pubmed.ncbi.nlm.nih.gov/28276612/">dietary changes</a> are required alongside exercise for these to occur. Exercise may even counteract some of the <a href="https://pubmed.ncbi.nlm.nih.gov/25217888/">negative effects of a high fat diet</a>, but not all.</p>
<p>Regardless, exercise may still help the good bacteria in our gut, called <em>A. muciniphila</em>, stick to the stomach lining. This better promotes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989796/">mucus secretion</a> which is important as mucus protects the bacteria from being carried out of the intestine with the digested food. </p>
<p>Studies looking at the immune system have also found that exercise decreases <a href="https://pubmed.ncbi.nlm.nih.gov/21555560/">inflammatory signals</a> and promotes a more “regulated” environment, in the gut lining and beyond. This reduces the chances of developing gut diseases. What’s really interesting about <em>A. muciniphila</em> is that it has been found to <a href="https://pubmed.ncbi.nlm.nih.gov/23671105/">reverse weight gain</a> from a high fat diet and insulin resistance in mice. </p>
<p>This study also showed that giving mice <em>A.muciniphila</em> also caused an increase in the cannabis-like molecules that our bodies naturally make, termed <a href="https://www.sciencedirect.com/topics/neuroscience/endocannabinoids">endocannabinoids</a>. Among other functions in the body, endocannabinoids are involved in controlling gut inflammation and our <a href="https://gut.bmj.com/content/57/4/438">gut barrier</a> (the front-line molecules that provide a physical immune defence from external attacks). </p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4789136/">endocannabinoid system</a> is also involved with feeding behaviour by controlling brain signals. Specific endocannabinoids are increased when we feel hungry, and released in the gut when we feel full. The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4789136/">endocannabinoid system</a> is overactive in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2925525/">people who are obese</a>. </p>
<p>Different gut bacteria can change the levels of the <a href="https://pubmed.ncbi.nlm.nih.gov/17159985/">different components</a> that make up the endocannabinoid system. Researchers used prebiotics to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2925525/">change microbial composition</a> in mice. They saw a decrease of one type of endocannabinoid and a cannabinoid receptor in an obese mouse. They also saw that the prebiotics made bacteria and toxins less able to pass from the mouse’s gut into its bloodstream.</p>
<p>This led to reduced bacterial components found in the blood and reduced fat cell production. A healthy diet improves the diversity and richness of gut bacteria, as does exercise – possibly even through the same few bacterial species mentioned earlier. Although this needs to be tested in humans, the results from these studies show the potential interaction between the microbial population in the gut with diet and exercise to bring about an improved metabolism. </p>
<p>More recently, researchers have shown runners and cyclists <a href="https://escholarship.org/uc/item/426788xv">produce more endocannabinoids</a> in their blood, which provides some pain relief and <a href="https://pubmed.ncbi.nlm.nih.gov/30534062/">improves mood</a>. However, it’s not known whether these changes are short lived or whether they bring about long-term changes in the gut microbiome.</p>
<p>It is tempting to speculate that exercise can change the composition of the gut microbiome and influence well-being, all through a system that has the ability to have a three-way conversation. It remains to be seen if we can manipulate this through diet and/or specific probiotics – but we should not underestimate how we are shaped by our gut residents both at the metabolic and physical level.</p><img src="https://counter.theconversation.com/content/140003/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>Current research suggests that exercise causes a number of positive changes in our gut microbiome.Rachael Rigby, Senior Lecturer in Gastro-Intestinal Health, Lancaster UniversityKaren Wright, Lecturer in Biomedical and Life Sciences, Lancaster UniversityLicensed 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>
<hr>
<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/1319282020-02-18T11:38:07Z2020-02-18T11:38:07ZMediterranean diet increases gut bacteria linked to healthy ageing in older adults<figure><img src="https://images.theconversation.com/files/315907/original/file-20200218-10980-1xipsm5.jpg?ixlib=rb-1.1.0&rect=0%2C38%2C6402%2C3105&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Half the participants were asked to eat more vegetables, legumes, fruits, nuts, olive oil, and fish -- and less red meat and dairy.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/panoramic-banner-fresh-healthy-food-heart-622969142">stockcreations/ Shutterstock</a></span></figcaption></figure><p>As our global population is <a href="https://www.un.org/en/sections/issues-depth/ageing/">projected to live longer</a> than ever before, it’s important that we find ways of helping people live healthier for longer. <a href="https://theconversation.com/keeping-fit-how-to-do-the-right-exercise-for-your-age-108851">Exercise</a> and <a href="https://theconversation.com/mediterranean-diet-may-protect-your-brain-in-old-age-new-finding-suggests-70909">diet</a> are often cited as the best ways of maintaining good health well into our twilight years. But recently, research has also started to look at the role our gut – specifically our microbiome – plays in how we age. </p>
<p>Our latest study has found that <a href="https://gut.bmj.com/content/early/2020/01/31/gutjnl-2019-319654">eating a Mediterranean diet</a> causes microbiome changes linked to improvements in cognitive function and memory, immunity and bone strength.</p>
<p>The <a href="https://theconversation.com/your-gut-bacteria-dont-like-junk-food-even-if-you-do-41564">gut microbiome</a> is a complex community of trillions of microbes that live semi-permanently in the intestines. These microbes have co-evolved with humans and other animals to break down dietary ingredients such as <a href="https://www.sciencealert.com/inulin-is-being-added-to-many-foods-but-it-could-be-causing-stomach-problems">inulin</a>, <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/arabinoxylan">arabinoxylan</a> and <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12244">resistant starch</a>, that the person can’t digest. They also <a href="https://www.ncbi.nlm.nih.gov/pubmed/28588016">help prevent disease-causing bacteria</a> from growing.</p>
<p>However, the gut microbiome is extremely sensitive, and many things including diet, the medications you take, your genetics, and even conditions like <a href="https://www.ncbi.nlm.nih.gov/pubmed/26323629">inflammatory bowel disease</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039952/">irritable bowel syndrome</a>, can all <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483960/">change the gut microbiota community</a>. The gut microbiota plays a such a huge role in our body, it’s even linked to behavioural changes, including <a href="https://www.ncbi.nlm.nih.gov/pubmed/31144383">anxiety and depression</a>. But as for other microbiome-related diseases such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/30366260">type 2 diabetes</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5933040/">obesity</a>, changes in the microbiome are only part of the issue – the person’s genetics and bad lifestyle are major contributing factors.</p>
<p>Since our everyday diets have such a big affect on the gut microbiome, our team was curious to see if it can be used to promote healthy ageing. We looked at a total of 612 people aged 65-79, from the UK, France, the Netherlands, Italy and Poland. We asked half of them to change their normal diet to a <a href="https://www.everydayhealth.com/mediterranean-diet/guide/#prosandcons">Mediterranean diet</a> for a full year. This involved eating more vegetables, legumes, fruits, nuts, olive oil and fish, and eating less red meat, dairy products and saturated fats. The other half of participants stuck to their usual diet.</p>
<h2>Mediterranean microbiome</h2>
<p>We initially found that those who followed the Mediterranean diet had better cognitive function and memory, less inflammation, and better bone strength. However, what we really wanted to know was whether or not the microbiome was involved in these changes. </p>
<p>Interestingly, but not surprisingly, a person’s baseline microbiome (the species and number of microbes they had living in their gut before the study started) varied by country. This baseline microbiome is likely a reflection of the diet they usually ate, alongside where they lived. We found that participants who followed the Mediterranean diet had a small but insignificant change in their microbiome diversity – meaning there was only a slight increase in the overall number and variety of species present.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mediterranean-diet-may-protect-your-brain-in-old-age-new-finding-suggests-70909">Mediterranean diet may protect your brain in old age, new finding suggests</a>
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</em>
</p>
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<p>However, when we compared how strictly a person followed the diet with their baseline microbiome data and their microbiome after following the diet, we were able to identify two different gut microbe groups: diet-positive microbes that increased on the Mediterranean diet, and diet-negative microbes whose abundance was reduced while following the diet.</p>
<p>Diet-positive microbes are microbes that flourished in the Mediterranean diet. Diet-negative microbes either couldn’t metabolise the diet, or they were were unable to compete with diet-positive microbes. These diet-positive microbes were linked with less frailty and inflammation in the body, and higher levels of cognitive function. Losing the diet-negative microbes was also associated with the same health improvements. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315912/original/file-20200218-10976-1vg62vc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Those who followed the Mediterranean diet had more healthy microbes in their gut.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/human-microbiome-intestine-1220371276">Alpha Tauri 3D Graphics/ Shutterstock</a></span>
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<p>When we compared the changes in the number of these microbes in the treatment group (those on the Mediterranean diet) and the control group (those following their regular diet), we saw that the people who strictly followed the Mediterranean diet increased these diet-positive microbes. Although the changes were small, these finding were consistent across all five countries – and small changes in one year can make for big effects in the longer term.</p>
<p>Many of the participants were also pre-frail (meaning their <a href="https://www.england.nhs.uk/blog/frailty/">bone strength and density would start decreasing</a>) at the beginning of the study. We found the group who followed their regular diet became frailer over the course of the one-year study. However, those that followed the Mediterranean diet were less frail.</p>
<p>The link between frailty, inflammation, and cognitive function, to changes in the microbiome was stronger than the link between these measures and dietary changes. This suggests that the diet alone wasn’t enough to improve these three markers. Rather, the microbiome had to change too – and the diet caused these changes to the microbiome.</p>
<p>These types of studies are challenging and expensive, and the microbiome dataset is often difficult to analyse because there are many more data-points to study than there are people in the study. Our findings here were possible because of the large group sizes, and the length of the intervention. </p>
<p>However, we recognise that following a Mediterranean diet isn’t necessarily doable for everybody who starts thinking about ageing, usually around the age of 50. Future studies will need to focus on what key ingredients in a Mediterranean diet were responsible for these positive microbiome changes. But in the meantime, it’s clear that the more you can stick to a Mediterranean diet, the higher your levels of good bacteria linked to healthy ageing will be.</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>This article is part of a series tied 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/uk/topics/medicine-made-for-you-82269">Read more here</a>.</em></p><img src="https://counter.theconversation.com/content/131928/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul O'Toole is a founder of 4D Pharma Cork Ltd., a company developing microbiome-based diagnostics and therapeutics for IBS and cancer, which has had no material influence on this article.</span></em></p>Our research found that following a Mediterranean diet was linked with less frailty, inflammation, and maintaining better cognitive function.Paul O'Toole, Professor of Microbial Genomics, School of Microbiology and APC Microbiome Institute, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1025792018-11-28T19:07:34Z2018-11-28T19:07:34ZExplainer: what is irritable bowel syndrome and what can I do about it?<figure><img src="https://images.theconversation.com/files/247435/original/file-20181127-130890-1bspxq6.jpg?ixlib=rb-1.1.0&rect=51%2C0%2C5760%2C3388&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Women are twice as likely to be diagnosed with irritable bowel syndrome as men.</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>Irritable bowel syndrome (IBS) is a common disorder that affects <a href="https://www.ncbi.nlm.nih.gov/pubmed/16409310">one in ten Australians</a>, and <a href="https://www.ncbi.nlm.nih.gov/pubmed/25734736">twice as many women</a> as men. Its symptoms include chronic abdominal pain, constipation or diarrhoea, and bloating. These have a significant <a href="https://www.ncbi.nlm.nih.gov/pubmed/19124023">impact on a person’s quality of life</a>.</p>
<p>Many people use the term irritable bowel syndrome to describe general symptoms of gut and bowel dysfunction. But diagnosis requires meeting strict, diagnostic criteria. Known as the <a href="https://www.ncbi.nlm.nih.gov/pubmed/27144617">ROME criteria</a>, these require a person to be experiencing abdominal pain, on average, at least one day per week. The pain must be associated with two or more of the following:</p>
<ul>
<li>defecation</li>
<li>a change in the frequency of stool</li>
<li>a change in the form (appearance) of stool</li>
<li>having occurred over the last three months with symptom onset at least six months before diagnosis.</li>
</ul>
<p>Tests aren’t always needed for a diagnosis if these symptoms are present. But an accurate diagnosis of IBS is important as some symptoms, such as pelvic pain, may overlap with other diseases such as endometriosis or inflammatory bowel disease. If other symptoms are present, a doctor <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/apt.13283">may need to perform</a> blood tests, pelvic ultrasound, endoscopy or stool tests to rule out similar disorders.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/i-have-painful-periods-could-it-be-endometriosis-101026">I have painful periods, could it be endometriosis?</a>
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<p>Some symptoms are considered “red flag” symptoms and should prompt further testing and specialist referral. For example, if you have rectal bleeding, weight loss and are aged over 50 when symptoms start, it is not IBS.</p>
<h2>What causes it?</h2>
<p>A single cause for IBS has not been identified. IBS may <a href="https://www.ncbi.nlm.nih.gov/pubmed/26202154">run in families</a>, but we still don’t know if this is due to shared genetics or environmental factors. An <a href="https://www.ncbi.nlm.nih.gov/pubmed/17661757">episode of gastroenteritis</a>, an infection caused by viruses or bacteria, increases the risk of developing IBS. But this is usually temporary and symptoms gradually improve.</p>
<p>People with IBS often also have <a href="https://www.ncbi.nlm.nih.gov/pubmed/28087404">anxiety and depression</a>. Research suggests early childhood trauma can <a href="https://www.ncbi.nlm.nih.gov/pubmed/18177446">predispose some people</a> to IBS in later life. This is because the gut and brain talk to each other through nerve signals, the release of gut or stress hormones, and other pathways. </p>
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<p>We have long known that emotions can directly alter gut function. But studies now show that gut function also affects emotions. One <a href="https://www.ncbi.nlm.nih.gov/pubmed/27444264">Australian study</a> indicated that for some people gut symptoms occur first and the psychological symptoms occur as a result. But this is not true for all people with IBS. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/stomach-and-mood-disorders-how-your-gut-may-be-playing-with-your-mind-50847">Stomach and mood disorders: how your gut may be playing with your mind</a>
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</em>
</p>
<hr>
<h2>What do I do?</h2>
<p>Non-drug treatments should be considered initially, and more than one treatment strategy may be needed to help improve symptoms.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/24076059">Good-quality evidence shows</a> a low-FODMAP diet reduces IBS symptoms. FODMAPs are carbohydrates that produce excess gas when digested. They can be found in roots such as onions and garlic, and fruits (or seeds) like legumes, apples, pears and mangoes. For the best result, a person should start a low-FODMAP diet under the guidance of an experienced dietitian.</p>
<p>It’s a common misconception that people should keep to a low-FODMAP diet for life. Foods like onions, which are high in FODMAPs, are also good prebiotics and promote the growth of friendly gut bacteria. Restricting these can result in low <a href="https://www.bmj.com/content/361/bmj.k2179">gut bacterial diversity</a>, which is linked to autoimmune diseases and obesity. That’s another reason a dietician should guide people through the diet over a few weeks and avoid unnecessary dietary restriction.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247647/original/file-20181128-32185-zurod7.jpg?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>
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<span class="caption">FODMAP foods include onions, but these also promote the growth of friendly gut bacteria.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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<p>Simple dietary measures include adding <a href="https://gi.org/wp-content/uploads/2014/08/IBS_CIC_Monograph_AJG_Aug_2014.pdf">more soluble fibre</a> to the diet. This can include psyllium, which can be bought as a powder from chemists and health food shops. Insoluble fibres like bran are generally unhelpful. </p>
<p>A trial of probiotics might help. These could be trialled for one month and then re-evaluated by the GP, but are unlikely to be useful if used indefinitely. Exercise <a href="https://www.ncbi.nlm.nih.gov/pubmed/21206488">has been shown</a> in randomised trials to improve gut symptoms in people with IBS.</p>
<p>Managing stress and anxiety are key to improving symptoms for many people. Psychological therapies have been <a href="https://gi.org/wp-content/uploads/2014/08/IBS_CIC_Monograph_AJG_Aug_2014.pdf">shown in trials</a> to help symptoms more than placebo or other interventions. This is particularly so when the psychologist is interested in IBS.</p>
<p>Clinical trials have also shown that, for some people, hypnotherapy that is directed at the gut is <a href="https://www.ncbi.nlm.nih.gov/pubmed/27397586">just as effective</a> as a low-FODMAP diet. The benefits are still seen at six months. Hypnotherapy is not for everyone, however, and multiple sessions are needed for symptoms to improve. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247645/original/file-20181128-32230-1k9gk5g.jpg?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"></a>
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<span class="caption">Peppermint oil can help reduce stomach cramps related to IBS.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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<h2>What about medications?</h2>
<p>IBS affects quality of life but it doesn’t change a person’s risk of early death or cancer. So, treatments should have few side effects to be acceptable. Clinical trials have shown that medications such as <a href="https://www.bmj.com/content/337/bmj.a2313">peppermint oil (usually given in capsules) can reduce</a> troublesome abdominal cramps with minimal side effects. </p>
<p>Melatonin can <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1774717/">improve symptoms</a> through better sleep quality where sleep is disturbed.</p>
<p>The choice of drug should be tailored to each person’s symptoms. For instance, low-dose antidepressants can be helpful for some people, especially where significant depression or anxiety symptoms exist together with IBS. Medications that <a href="https://www.ncbi.nlm.nih.gov/pubmed/12848628">reduce inflammation</a> are <a href="https://www.ncbi.nlm.nih.gov/pubmed/25765462">generally unhelpful</a>, as consistent and clinically apparent inflammation is not part of the syndrome.</p>
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Read more:
<a href="https://theconversation.com/so-you-think-you-have-ibs-coeliac-disease-or-crohns-heres-what-it-might-mean-for-you-39128">So you think you have IBS, coeliac disease or Crohn’s? Here’s what it might mean for you</a>
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<p>A few new approaches are being trialled for IBS, including faecal transplants and new medications. But all of these need better long-term data before they appear on the market.</p><img src="https://counter.theconversation.com/content/102579/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Suzanne Mahady 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>Irritable bowel syndrome causes abdominal pain and constipation or diarrhoea. These symptoms overlap with other disorders, so it’s important to get the correct diagnosis and then the best treatments.Suzanne Mahady, Gastroenterologist & Clinical Epidemiologist, Senior Lecturer, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1045702018-11-12T08:21:58Z2018-11-12T08:21:58ZHealth Check: should you take probiotics when you’re on antibiotics?<figure><img src="https://images.theconversation.com/files/245023/original/file-20181112-83596-15uhq79.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We still don't know what types of bacteria are truly beneficial.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/pharmaceutical-medicine-pills-tablets-capsules-bottle-1225918525?src=uiLH1UTsYbAJpMiuzGR4bg-1-5">Andry Jeymsss/Shutterstock</a></span></figcaption></figure><p>If you take antibiotics, there’s a <a href="https://jamanetwork.com/journals/jama/fullarticle/1151505">good chance</a> you’ll also get diarrhoea.</p>
<p>Antibiotics kill harmful bacteria that cause disease. But they also cause collateral damage to the microbiome, the complex community of bacteria that live in our gut. This results in a profound, though usually temporary, depletion of the beneficial bacteria. </p>
<p>One popular strategy to mitigate the disruption is to take a probiotic <a href="https://theconversation.com/we-know-too-little-about-probiotics-to-proclaim-their-virtues-33840">supplement</a> containing live bacteria during, or following, a course of antibiotics.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/healthy-guts-are-swarming-with-bugs-so-what-do-they-do-65105">Healthy guts are swarming with bugs, so what do they do?</a>
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<p>The logic is simple: beneficial bacterial in the gut are damaged by antibiotics. So why not replace them with the “beneficial” bacterial strains in probiotics to assist gut bacteria returning to a “balanced” state? </p>
<p>But the answer is more complicated.</p>
<p>There is currently <a href="https://jamanetwork.com/journals/jama/fullarticle/1151505">some evidence</a> that taking probiotics can prevent antibiotic-associated diarrhoea. This effect is relatively small, with 13 people needing to take probiotics for one episode of diarrhoea to be averted. </p>
<p>But these studies have often neglected to evaluate potential harms of probiotic use and haven’t looked at their impact on the wider gut microbiome. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/YB-8JEo_0bI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<h2>Pros and cons of probiotics</h2>
<p>The assumption that there is little downside to taking probiotics was challenged in a <a href="https://www.ncbi.nlm.nih.gov/pubmed/30193113">recent Israeli study</a>.</p>
<p>The participants were given antibiotics and split into two groups: the first group was given an 11-strain probiotic preparation for four weeks; the second was given a placebo, or dummy pill. </p>
<p>The researchers found the antibiotic damage to the gut bacteria of those in the first group allowed the probiotic strains to effectively colonise the gut. But this colonisation delayed the normal recovery of the microbiota, which remained perturbed for the entire six month study period. </p>
<p>In contrast, the microbiota of the second group returned to normal within three weeks of finishing antibiotics. </p>
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<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>
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<p>This research exposes a perhaps unexpected truth: we still don’t know what types of bacteria are truly beneficial or even what constitutes a healthy microbiome. </p>
<p>The answer is unlikely to be that individual bacterial strains are particularly helpful. </p>
<p>It’s more likely a diverse community of thousands of different types of microbes working together can provide health benefits. This microbial community is as individual as each one of us, meaning there is not just one configuration that will result in health or illness. </p>
<p>So, it’s unlikely that the addition of one or even 11 strains of bacteria in a probiotic could somehow balance this complex system. </p>
<h2>A more effective (but less palatable) alternative?</h2>
<p>The Israeli study also explored an alternative approach to microbiome restoration. </p>
<p>One group of participants had their own stool collected and frozen prior to antibiotic treatment. It was then re-instilled into their gut at the end of the antibiotic therapy. </p>
<p>This treatment, known as autologous faecal transplantation, was able to restore the microbiome to original levels after just eight days. The other group took 21 days to recover. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/poo-transplants-and-probiotics-does-anything-work-to-improve-the-health-of-our-gut-65480">Poo transplants and probiotics – does anything work to improve the health of our gut?</a>
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<p>This approach has also been <a href="http://stm.sciencemag.org/content/10/460/eaap9489">shown to effectively restore</a> the gut microbiome following combined antibiotic and chemotherapy treatment. These patients are predictably at risk of serious complications, such as bloodstream infection, as a result of microbiome disruption. </p>
<p>Research currently underway will help us understand whether microbiome restoration with autologous faecal transplantation will translate into tangible benefits for these patients.</p>
<p>But such an approach would not be a realistic option for most people.</p>
<h2>Feed the good bacteria</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245008/original/file-20181112-83582-1927hn9.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">Good food for gut bacteria.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/O594WRcWphI">Roosa Kulju</a></span>
</figcaption>
</figure>
<p>A more practical strategy to aid recovery is to provide the good bacteria in your gut with their preferred source of nutrition: fibre. Fibrous compounds pass undigested through the small intestine and into the colon, where they act as fuel for bacterial fermentation. </p>
<p>So if you’re taking antibiotics or have recently finished a course, make sure you eat plenty of vegetables, fruit and wholegrains. Your gut bacteria will thank you for it.</p><img src="https://counter.theconversation.com/content/104570/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>Probiotics might avert a case of diarrhoea, or they could mean your gut takes longer to return to normal.Lito Papanicolas, Infectious diseases specialist and PhD candidate, South Australian Health & Medical Research InstituteGeraint Rogers, Professor; Director, Microbiome Research, South Australian Health & Medical Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1060952018-11-01T16:02:07Z2018-11-01T16:02:07ZMoving to another country could mess with your gut bacteria<figure><img src="https://images.theconversation.com/files/243479/original/file-20181101-83644-1juu5wq.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-illustration/gut-bacteria-microbiome-inside-large-intestine-639806734?src=EOpvIjrmRApNR067Ofu3eA-1-5">Anatomy Insider/Shutterstock</a></span></figcaption></figure><p>Moving to a new country can be challenging, not just for us but also for our bacteria. A compelling new study <a href="https://doi.org/10.1016/j.cell.2018.10.029">published in Cell</a> suggests migration between certain countries can profoundly affect the bacteria that live in our digestive systems, with important implications for our health.</p>
<p>We know immigrants to the US are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579065/">more susceptible</a> to developing obesity and metabolic diseases such as diabetes than either people from the same countries who don’t migrate or <a href="http://www.rimed.org/rimedicaljournal/2015/01/2015-01-43-cont-heney.pdf">native-born US citizens</a>, but we don’t really understand why. To try to understand this phenomenon from a health perspective, researchers from the University of Minnesota conducted a large, in-depth study of Chinese and Thai immigrants moving to the US. The authors looked at the diet, gut microbes and <a href="https://www.nhs.uk/common-health-questions/lifestyle/how-can-i-work-out-my-body-mass-index-bmi">body mass index</a> of the immigrants before and after they moved. The evidence showed that the longer immigrants spent in the US, the less diverse their bacteria became, and that this was linked to rising obesity.</p>
<p>The human gut is home to hundreds of different species of bacteria known collectively as the “gut microbiome”. As well as breaking down food, this community of microorganisms helps our bodies <a href="https://gut.bmj.com/content/early/2018/06/22/gutjnl-2018-316723">fight and prevent disease</a>. There is even tantalising evidence that the gut microbiome can <a href="https://gutpathogens.biomedcentral.com/track/pdf/10.1186/1757-4749-5-3">influence our mental health</a>.</p>
<p>A more diverse gut microbiome is associated with <a href="https://www.bmj.com/content/361/bmj.k2179">a healthier digestive system</a>. And things that reduce this diversity, such as antibiotics, stress or changes in diet, can <a href="https://www.ncbi.nlm.nih.gov/pubmed/25126780">help make us more susceptible to conditions</a> like obesity or irritable bowel disease.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243301/original/file-20181031-122150-1rd2y4x.JPG?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"></a>
<figcaption>
<span class="caption">Migration from Southeast Asia to the US comes with a loss in gut bacteria diversity.</span>
<span class="attribution"><span class="source">Vangay et al</span></span>
</figcaption>
</figure>
<p>The study compared a total of 514 healthy women, split into those born and living in Thailand, those born in Southeast Asia who later moved to the US, and those born in the US to immigrant parents originally from Southeast Asia. It found that changes to the gut microbiome began as soon as the immigrants arrived in the US and continued to change over decades. The longer they spent living there, the more their microbiomes began to resemble those of native-born Americans of European ethnic origin. The majority of participants, living in the US, also gained weight during the course of the study. </p>
<p>The combination of species that make up our gut microbiomes is strongly influenced by our diets, and so people from different parts of the world tend to have different bacteria. Western guts commonly contain lots of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5679392/"><em>Bacteroides</em> species</a>, which are good at digesting animal fats and proteins. The guts of people with <a href="https://www.nature.com/articles/nature11053">non-Western diets</a> rich in plants tend to be dominated by <em>Prevotella</em> species, which are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463488/">good at digesting plant fibre</a>. The new study revealed that strains of bacteria from the immigrants’ native countries, particularly <em>Prevotella</em> species, were completely lost, as were relevant enzymes for digesting important plant fibres.</p>
<h2>Cause or effect?</h2>
<p>Studies that suggest that the microbiome can influence human health or disease are often challenged because it is hard to distinguish between cause and effect. In this case, it’s unclear whether changes in the microbiome are directly contributing to the high incidence of obesity in US immigrants. It may be some time before we fully understand whether a less diverse microbiome leads to obesity, or if obesity leads to a less diverse microbiome.</p>
<p>Most of our knowledge in this area comes from studying laboratory mice. Ground-breaking studies from the lab of US biologist <a href="https://www.nature.com/articles/nature05414">Jeff Gordon</a> first found a link between obesity and the gut microbiome in 2006, when they showed mice gained weight when they were given gut bacteria from obese humans. But, we also know high-fat diets <a href="https://www.nature.com/articles/srep32484">drive obesity regardless</a> of what’s in the gut microbime. So it would be premature to suggest that the microbiome alone is responsible for obesity.</p>
<p>With <a href="http://www.oecd.org/berlin/Is-migration-really-increasing.pdf">immigration increasing</a> and eating habits evolving, it is important we better understand how changes in populations, cultures and diets can impact human microbiomes so that we can spot potential health problems. For example, we know that refugees, <a href="https://link.springer.com/article/10.1007/s10903-016-0461-8">particularly children</a>, are more prone to developing obesity so we need to develop novel strategies to combat this. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372278/">Education is one aspect</a> and another is tackling poverty, which tends to be <a href="https://www.irp.wisc.edu/publications/focus/pdfs/foc262e.pdf">higher among immigrants</a> than native-born citizens. But if the gut microbiome really is central to health and disease then finding ways to treat it directly by prescribing things like <a href="https://theconversation.com/probiotics-a-first-look-at-whats-going-on-in-the-gut-102621">probiotics</a> or even <a href="https://theconversation.com/why-poo-transplants-are-nothing-to-be-sniffed-at-49319">faecal transplants</a> could help. One day we might even have <a href="https://www.nytimes.com/2015/11/10/health/fecal-transplants-made-somewhat-more-palatable.html">microbial “pills”</a> that could help migrants combat the changes to their gut microbiomes and settle more healthily in their new homes.</p><img src="https://counter.theconversation.com/content/106095/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chloe James is affiliated with The Microbiology Society. </span></em></p><p class="fine-print"><em><span>Ian Goodhead receives funding from the Wellcome Trust and Royal Society </span></em></p>Study finds changes to gut microbiome begin as soon as migrants move to the US and continue to change over decades.Chloe James, Senior Lecturer in Medical Microbiology, University of SalfordIan Goodhead, Lecturer in Infectious Diseases, University of SalfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1055962018-10-25T10:38:06Z2018-10-25T10:38:06ZOrganic food and cancer risk – gut microbe expert on latest research<figure><img src="https://images.theconversation.com/files/242112/original/file-20181024-71014-1edh3lv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cutting out pesticides by eating only organic food could slash your cancer risk.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Organic food is an over-hyped and overpriced fad, <a href="https://metro.co.uk/2016/10/17/actually-organic-food-is-pretty-much-a-waste-of-money-according-to-science-6196186/">according to many people</a>. But a <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2707948">recently published study</a> which followed nearly 69,000 French people over four and a half years seems to indicate there is a link between eating organic foods and a lower cancer risk.</p>
<p>The study found the regular eaters of 16 types of organic products were protected against several cancers by about a quarter. The foods included fruit, vegetables, bread, flour, eggs, meat and cereals. </p>
<p>More than <a href="https://ec.europa.eu/agriculture/organic/eu-policy/data-statistics_en">20% of EU land</a> is now allocated for organic farming and the organic sector is booming. But until now there has been no clear consensus on whether eating organic food is worth the extra cost. So is it time to throw out all your fruit and veg and only shop organic in the future?</p>
<h2>Going organic</h2>
<p>The study suggests people who regularly eat organic plant foods have a reduction in risk of common cancers. The data also shows a reduction for breast cancer after the menopause – but not before.</p>
<p>But while these results suggest a relationship, it is a long way from proof. This is because the study itself was too short and has the usual biases of observational designs – in that people who are healthier are more likely to eat healthier foods. And while the authors adjusted for body weight, social class and educational level, as well as other differences, and still found a consistent effect, the possibility of bias still remains on any single observational study.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/242115/original/file-20181024-71035-1mb547s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">People who eat more organic foods may be less likely to develop certain cancers, the French study suggests.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>The results, however are most convincing for a reduction in cancer of the immune system called Non-Hodgkin’s lymphoma. This is because two previous studies (also longitudinal and observational) – the largest being a study of 680,000 women over nine years – <a href="https://www.nature.com/articles/bjc2014148">also showed the same preventive effects</a>. The fact that all three studies show a reduction of risk for this type of cancer (by chance or bias alone) is more indicative that there could be a link between organic eating and a lower cancer risk. </p>
<h2>Herbicides and health</h2>
<p>There is no hard evidence that the taste or nutrient differences (fibre, vitamins and minerals) of organic vegetables are very different to regular varieties – although <a href="https://www.ncbi.nlm.nih.gov/pubmed/24968103">analysis suggests</a> they contain more polyphenols. These are compounds that often give plants their colour and provide antioxidant defences and are generally <a href="https://www.medicalnewstoday.com/articles/319728.php">beneficial for human health</a>.</p>
<p>In the US and Europe, fruits and vegetables are regularly sprayed with a range of <a href="https://theconversation.com/new-research-suggests-common-herbicides-are-linked-to-antibiotic-resistance-87678">pesticides and herbicides</a>. Organic plants do still have detectable levels of herbicides and pesticides, but <a href="http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2016.4611/pdf">they are five times lower</a>
than non-organic products. Many common fruits and cereals such as oats often have high levels – which aren’t reduced much by washing or peeling.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-controversial-weedkiller-has-won-a-new-five-year-lease-in-europe-but-citizens-are-fighting-back-88363">A controversial weedkiller has won a new five-year lease in Europe, but citizens are fighting back</a>
</strong>
</em>
</p>
<hr>
<p>So it could well be that ingesting chemically treated plants over years may actually increase some cancers. <a href="https://theconversation.com/stop-worrying-and-trust-the-evidence-its-very-unlikely-roundup-causes-cancer-104554">A US jury</a>, for example, recently awarded millions of dollars in damages to a groundsman with Non-Hodgkin’s lymphoma who regularly used <a href="https://theconversation.com/a-controversial-weedkiller-has-won-a-new-five-year-lease-in-europe-but-citizens-are-fighting-back-88363">the weed killer Glyphosate</a> (Roundup). This weedkiller is widely used around the world and in more than five million acres of farmland in the UK alone.</p>
<p>The government and the EU maintains that these chemicals are safe for humans at doses found in food. But the safety thresholds are based on old-fashioned lab animal data – where rodents are given doses a thousand times higher and see if they develop extra cancers. The safety tests for foods and chemicals have not changed for decades and do not include the long-term effects, for example, on our gut microbiomes. </p>
<h2>A gut issue</h2>
<p>We have 100 trillion microbes in our lower intestines <a href="https://theconversation.com/i-spent-three-days-as-a-hunter-gatherer-to-see-if-it-would-improve-my-gut-health-78773">that make up a community</a>
that are crucial for the immune system and for the body’s response to cancer and cancer therapies – such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/29302014">immunotherapy for melanoma</a>. These microbes and their genes are much more sensitive to chemicals than we are, and this can lead to disruption in their <a href="https://theconversation.com/postbiotics-and-smart-toilets-new-era-of-harnessing-our-microbial-chemicals-to-keep-us-slim-and-healthy-96861">metabolism and the chemicals they produce</a>.</p>
<p>This new knowledge of the importance of a healthy gut microbiome casts doubt on official advice that all pesticides and herbicides are safe for us over long periods of time. And greater scrutiny of the safety of these widely used chemicals in our foods needs to be carried out in well-funded clinical trials – over years, not weeks. </p>
<p>There may of course be no direct effects on humans. But, as yet, no one has provided evidence to show that such chemicals are not harmful long-term for our immune system. So, while the risks for individuals are likely to be low, until we know for sure, for those who like eating lots of plants, spending a bit more for organic fruit and veg (and porridge oats) may be a price worth paying to keep your gut microbes healthy.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-sauerkraut-is-leading-a-food-revolution-60133">How sauerkraut is leading a food revolution</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/105596/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tim Spector receives grant funding from the MRC, NIHR, Wellcome Trust, EU. CDRF. He is a consultant to Zoe Global Ltd and author of "The Diet Myth: the science behind what we eat". Orion 2016 </span></em></p>New research suggests people who eat organic plant foods have a reduction in risk of common cancers.Tim Spector, Professor of Genetic Epidemiology, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/989382018-10-17T00:05:40Z2018-10-17T00:05:40ZCurious Kids: Why do we need food?<figure><img src="https://images.theconversation.com/files/224818/original/file-20180626-19375-1o9ueyg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Food helps recharge your batteries.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Why do we need food? – Milo, age 5, Cowes, Victoria.</strong></p>
</blockquote>
<hr>
<p>Just like a mobile phone needs to be recharged every day, so does your body. You need to eat food and drink water every day to keep your body going. Food gives you energy to grow, play games, be healthy and learn. Every day, you need to eat different foods from the five food groups.</p>
<p>The five food groups are:</p>
<ol>
<li><p>grains</p></li>
<li><p>fruit</p></li>
<li><p>vegetables</p></li>
<li><p>milk or vegetarian choices</p></li>
<li><p>meat or vegetarian choices</p></li>
</ol>
<p>Your body also needs nuts, healthy oils and spreads in small amounts too.</p>
<p>Fresh food is best. Foods that are processed and contain unhealthy fats and sugar, which is why cake, lollies and soft drinks are not recommended. If you eat lots of these your body can get sick.</p>
<h2>The food journey</h2>
<p>The food you eat starts a journey in your mouth where your teeth and tongue chew it into smaller parts. When you swallow, the chewed food passes into a long tube called your digestive system. Here, the food is broken down into tiny pieces that can be used by your body. This is called digestion.</p>
<p>Foods like wholegrain bread, vegetables and fruit contain carbohydrates and fibre, whereas nuts, oils and spreads contain healthy fats. Your body uses the carbohydrates and fats as energy so you can run and play games. Fibre helps the food pass through the long tube easily so you can poo in the toilet.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238017/original/file-20180926-149976-kli4ig.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">Vegetables and fruit contain carbohydrates and fibre.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/sonnysideup/2577052946/in/photolist-4VJ54m-UqaWAk-o6rN7e-buRpwD-6FfWnM-gYKxjX-8zjRbQ-RzmmD6-cKG5aq-JPT7H-eW99jx-eaEfLz-P6RWJJ-85PsMA-6RTGVP-JoThHi-bcudxn-pdishq-otTEjB-c4Dh7Q-czvFK7-2UiPZf-DAgHjn-cn4fmf-ieBtCe-9g71vb-Xq6EHN-TgyYEB-fCGfjT-6FRU2g-qEoEH-fwgw6-8dp3hM-euS1P1-2aaEPAu-5z28xq-e2cUDB-8NjYfB-nZ7Ate-2bc4WUL-ayDwZT-25Svy5G-baNkFa-22e8XPb-5tzw5G-2bad59b-27SDuMt-aBhbhM-24gdTSu-Zx4mK5">Flickr/Sonny Side Up!</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Milk, meat, eggs and legumes are high in protein. Your body uses protein to grow hair, fingernails and skin and fix any cuts. </p>
<p>Vitamins and minerals are in your food in small amounts. They help your body stay healthy.</p>
<p>Vitamin A is found in meat and orange vegetables like carrots, and helps your eyes see in the dark. Vitamin C is found in oranges, and helps your body fight off nasty bugs that can make you sick. </p>
<p>Minerals like calcium, which is found in dairy foods, helps your bones grow strong. Iron, found in meats and some breakfast cereals, helps your blood carry oxygen throughout your body.</p>
<h2>Tummy rumbles</h2>
<p>Do you ever hear any noises like grumbling or growling in your tummy? When your tummy rumbles, it means you are hungry and need to eat food. When your tummy feels full you can stop eating - you don’t want to feel too full. </p>
<p>Water is the best drink for you every day, and helps your body and brain to work properly. If you have been playing sport that makes you hot and sweaty, you’ll need to drink some water.</p>
<p>Without food and water every day, you will feel tired and you won’t be able to play and learn well.</p>
<p>As long as you eat a variety of foods each day and drink water regularly during the day, you’ll be okay.</p>
<p><em>Note to teachers and carers: <a href="http://www.refreshedschools.health.wa.gov.au">Refresh.ED</a> is an online portal that prepares school teachers for nutrition education with curriculum support materials (teaching materials, classroom activities).</em></p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:</em></p>
<p><em>* Email your question to curiouskids@theconversation.edu.au
<br>
* Tell us on <a href="https://twitter.com/ConversationEDU">Twitter</a></em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/98938/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Devine receives funding from Healthway, Western Australian Department of Health and Western Australian Department of Education and other funding bodies for scientific research. Dr Devine owns shares in Wide Open Agriculture and Keytone Dairy and is a co-director of Australasian Health Development Network. She is affiliated with the Nutrition Society of Australia and a friend of Dietitians Association of Australia.</span></em></p>Just like a mobile phone, your body needs to be recharged every day. You need to eat food and drink water every day to keep your body going. Some foods are better than others at helping you stay well.Amanda Devine, Professor of Public Health Nutrition, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1032632018-09-18T14:12:31Z2018-09-18T14:12:31ZHousehold cleaning products could be making children overweight<figure><img src="https://images.theconversation.com/files/236836/original/file-20180918-158213-1jrxu50.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Put down that bleach.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/little-latin-boy-reaching-toxic-cleaning-1011349939?src=cixOQ_Z9DcCm4t3bNLgrbA-1-2">Ruslana Lurchenko/Shutterstock</a></span></figcaption></figure><p>Keeping household surfaces clean is a daily chore for most families, but there may be unseen consequences for children’s health. Overusing cleaning products can increase the risk of childhood obesity, according to new research, as exposure causes changes in the bacteria which live in children’s guts. </p>
<p><a href="http://www.cmaj.ca/content/190/37/E1097">The research</a>, published in the Canadian Medical Association Journal, compared how much mothers reported using cleaning products with the rate of obesity in 757 children at the age of three. Faecal samples were taken from the infants at three to four-months-old and the researchers investigated associations between microbial changes and being overweight at age three. The researchers found a link between heavy use of cleaning products, microbial changes and children with a higher body mass index (BMI). </p>
<p>However, higher disinfectant usage was also reported among households with infants who received antibiotics around the time of birth; who were exposed to cigarette smoke; or were delivered by caesarean section. The results may therefore reflect several interlinking factors. Obesity was less likely to occur in breastfed children, but breastfeeding was also linked to lower disinfectant usage, which makes it difficult to tease apart these two factors. </p>
<h2>The microflora of the human gut</h2>
<p>The prevalence of obesity has seen a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4859313/">dramatic global rise</a> over the last 30 years, leading to increases in related health problems. At the same time, our understanding of the microscopic life we share our living spaces with has grown. Most microorganisms are not harmful and many of them can colonise our digestive system, forming our “microflora”.</p>
<p>We pick up our microflora <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2785767/">from our environment</a>, starting from our mothers, and then other household members and even our pets, throughout our lives. Most of our gut microflora are obtained through the mouth, for example during eating, drinking and brushing our teeth. All of our bodily surfaces, including gut, airways and skin, are covered by bacteria. Household cleaning products <a href="https://www.ncbi.nlm.nih.gov/pubmed/22164261">kill off microorganisms</a>, including the good ones, preventing them from reaching our guts.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/236869/original/file-20180918-158228-1xxaju4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A diverse bacterial community in the gut is good for health overall.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/microbiome-human-gut-1139164184?src=-C--dJ5UxuSixx6LKvLOZA-1-2">Alpha Tauri 3D Graphics/Shutterstock</a></span>
</figcaption>
</figure>
<p>We’ve all heard that it’s good for children to “play in the dirt” and there’s a lot of truth in that. Having a diverse microflora is healthy. Dominance or “overgrowth” of one particular group of bacteria can lead to an increased risk of developing many health problems, including <a href="http://science.sciencemag.org/content/341/6150/1241214">obesity</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0092867412001043?via%3Dihub">allergies, inflammation and type 2 diabetes</a>. </p>
<p>The more “diverse” the community of bacteria that live in our gut, and the more balanced our diet is to sustain and feed those bacteria, the less chance there is of one type of bacteria associated with a disease being able to flourish. </p>
<h2>Gut bacteria and obesity</h2>
<p>Obesity has previously been linked to a <a href="http://www.nature.com/articles/nature05414">dominance of one certain type of bacteria</a>, known as Firmicutes, over another called Bacteriodetes, in the intestine. In the current study, Lachnospiraceae (a family of bacteria in the Firmicutes family), were found to be more abundant in infants from households that use cleaning products and in subsequently obese children. </p>
<p>Lachnospiraceae are also more efficient in breaking down food than other species, so that they extract more energy which causes weight gain as the human gut absorbs it. The exact mechanism linking gut microbiota to obesity is not currently well understood, but it is well established that certain bacteria, particularly the Firmicutes, can <a href="https://www.ncbi.nlm.nih.gov/pubmed/29196878">increase energy production from the diet</a> which <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5633527/">can increase the likelihood of obesity developing</a>. </p>
<p>Diseases often emerge from particular groups or even species of bacteria that dominate the rest. This recent research demonstrates that overusing cleaning products may promote this shift in microbial dominance. Childhood obesity may be one of several threats from our attempts to maintain sanitised environment for children, the results of which we’re only beginning to understand.</p><img src="https://counter.theconversation.com/content/103263/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rachael Rigby receives funding from Medical Research Council, Bowel Disease Research Fund. </span></em></p>A sanitised environment can mean fewer helpful bacteria. That has some surprising consequences for the health of children.Rachael Rigby, Senior Lecturer in Gastro-Intestinal Health, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.