tag:theconversation.com,2011:/uk/topics/chronic-inflammatory-diseases-1627/articlesChronic inflammatory diseases – The Conversation2022-11-07T13:35:27Ztag:theconversation.com,2011:article/1935032022-11-07T13:35:27Z2022-11-07T13:35:27ZWhat is inflammation? Two immunologists explain how the body responds to everything from stings to vaccination and why it sometimes goes wrong<figure><img src="https://images.theconversation.com/files/493585/original/file-20221104-18-efs0p0.jpg?ixlib=rb-1.1.0&rect=107%2C242%2C5883%2C3745&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Insect bites or stings, like the one on this person's hand, are a manifestation of inflammation.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cropped-hand-with-mosquito-bite-against-white-royalty-free-image/1187314357?phrase=insect%20bite&adppopup=true">Suthep Wongkhad/EyeEm via Getty Images</a></span></figcaption></figure><p>When your body fights off an infection, you develop a fever. If you have arthritis, your joints will hurt. If a bee stings your hand, your hand will swell up and become stiff. These are all manifestations of <a href="https://doi.org/10.1007/s11515-011-1123-9">inflammation</a> occurring in the body.</p>
<p>We are two <a href="https://scholar.google.com/citations?user=jJVj3sUAAAAJ&hl=en&oi=ao">immunologists</a> <a href="https://scholar.google.com/citations?user=af7TahQAAAAJ&hl=en&oi=ao">who study</a> how the immune system reacts <a href="https://pubmed.ncbi.nlm.nih.gov/?term=nagarkatti+p&sort=date">during infections, vaccination and autoimmune diseases</a> where the body starts attacking itself.</p>
<p>While inflammation is commonly associated with the pain of an injury or the many diseases it can cause, it is an important part of the normal immune response. The problems arise when this normally helpful function overreacts or overstays its welcome.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An image showing many small white cells swarming a larger sphere." src="https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493374/original/file-20221103-26-eq1cei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&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">Inflammation is a process in which antibody-producing cells – like the large beige cell on the left of this image – rush to the site of an infection to attack an invader, such as the flu virus in yellow.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/immune-response-to-a-virus-illustration-royalty-free-illustration/724237117?phrase=antibodies%20infection&adppopup=true">Juan Gaertner/Science Photo Library via Getty Images</a></span>
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<h2>What is inflammation?</h2>
<p>Generally speaking, the term inflammation refers to all activities of the immune system that occur where the body is trying to fight off potential or real infections, clear toxic molecules or recover from physical injury. There are <a href="https://doi.org/10.1186%2F1476-9255-1-1">five classic physical signs</a> of acute inflammation: heat, pain, redness, swelling and loss of function. Low-grade inflammation might not even produce noticeable symptoms, but the underlying cellular process is the same.</p>
<p>Take a bee sting, for example. The immune system is like a military unit with a wide range of tools in its arsenal. After sensing the toxins, bacteria and physical damage from the sting, the immune system <a href="https://theconversation.com/coronavirus-b-cells-and-t-cells-explained-141888">deploys various types of immune cells</a> to the site of the sting. These include <a href="https://www.niaid.nih.gov/research/immune-cells">T cells, B cells, macrophages and neutrophils</a>, among other cells.</p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/books/NBK26884/">B cells produce antibodies</a>. Those antibodies can kill any bacteria in the wound and neutralize toxins from the sting. <a href="https://doi.org/10.3389/fimmu.2012.00174">Macrophages and neutrophils engulf bacteria</a> and destroy them. <a href="https://doi.org/10.1038/d41586-021-00367-7">T cells don’t produce antibodies, but kill any virus-infected cell</a> to prevent viral spread. </p>
<p>Additionally, these immune cells produce <a href="https://doi.org/10.1177/1091581815584918">hundreds of types of molecules</a> called cytokines – otherwise known as mediators – that help fight threats and repair harm to the body. But just like in a military attack, inflammation comes with collateral damage.</p>
<p>The mediators that help kill bacteria also kill some healthy cells. Other similar mediating molecules cause blood vessels to leak, leading to accumulation of fluid and influx of more immune cells. </p>
<p>This collateral damage is the reason you develop swelling, redness and pain around a bee sting or after getting a flu shot. Once the immune system clears an infection or foreign invader – whether the toxin in a bee sting or a chemical from the environment – different parts of the inflammatory response take over and help repair the damaged tissue.</p>
<p>After a few days, your body will neutralize the poison from the sting, eliminate any bacteria that got inside and heal any tissue that was harmed. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram of a man showing two airways, one open and the other more constricted." src="https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493375/original/file-20221103-15-myadsi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Asthma is caused by inflammation that leads to swelling and a narrowing of airways in the lungs, as seen in the right cutaway in this image.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Asthma_(Lungs).png#/media/File:Asthma_(Lungs).png">BruceBlaus/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<h2>Inflammation as a cause of disease</h2>
<p>Inflammation is a double-edged sword. It is critical for fighting infections and repairing damaged tissue, but when inflammation occurs for the wrong reasons or <a href="https://theconversation.com/long-covid-how-researchers-are-zeroing-in-on-the-self-targeted-immune-attacks-that-may-lurk-behind-it-169911">becomes chronic</a>, the damage it causes <a href="https://theconversation.com/despite-its-disastrous-effects-covid-19-offers-some-gifts-to-medicine-an-immunology-expert-explains-what-it-can-teach-us-about-autoimmune-disease-174952">can be harmful</a>. </p>
<p><a href="https://doi.org/10.1111/j.1600-065x.2011.01020.x">Allergies</a>, for example, develop when the immune system mistakenly recognizes innocuous substances – like peanuts or pollen – as dangerous. The harm can be minor, like itchy skin, or dangerous if someone’s throat closes up.</p>
<p>Chronic inflammation damages tissues over time and can lead to <a href="https://doi.org/10.1038/s41591-019-0675-0">many noninfectious clinical disorders</a>, including cardiovascular diseases, neurodegenerative disorders, obesity, diabetes and some types of cancers. </p>
<p>The immune system can sometimes mistake one’s own organs and tissues for invaders, leading to inflammation throughout the body or in specific areas. This self-targeted inflammation is what causes the symptoms of <a href="https://doi.org/10.1289/ehp.99107s5661">autoimmune diseases</a> such as lupus and arthritis. </p>
<p>Another cause of chronic inflammation that researchers like us are currently studying is defects in the <a href="https://doi.org/10.3389/fimmu.2016.00160">mechanisms that curtail inflammation</a> after the body clears an infection.</p>
<p>While inflammation mostly plays out at a cellular level in the body, it is far from a simple mechanism that happens in isolation. Stress, diet and nutrition, as well as genetic and environmental factors, have all been shown <a href="https://doi.org/10.3389%2Ffimmu.2020.570083">to regulate inflammation</a> in some way. </p>
<p>There is still a lot to be learned about what leads to harmful forms of inflammation, but a <a href="https://doi.org/10.3390%2Fnu11081933">healthy diet</a> and <a href="https://doi.org/10.1016%2Fj.copsyc.2015.03.007">avoiding stress</a> can go a long way toward helping maintain the delicate balance between a strong immune response and harmful chronic inflammation.</p><img src="https://counter.theconversation.com/content/193503/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Prakash Nagarkatti receives funding from the National Science Foundation and the National Institutes of Health. </span></em></p><p class="fine-print"><em><span>Mitzi Nagarkatti receives funding from the National Institutes of Health.</span></em></p>Inflammation is a complicated and important part of how the immune system responds to threats to the body. But when the inflammatory response goes awry, it can lead to serious problems.Prakash Nagarkatti, Professor of Pathology, Microbiology and Immunology, University of South CarolinaMitzi Nagarkatti, Professor of Pathology, Microbiology and Immunology, University of South CarolinaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1899182022-09-12T16:41:24Z2022-09-12T16:41:24ZUltra-processed foods: it’s not just their low nutritional value that’s a concern<figure><img src="https://images.theconversation.com/files/483261/original/file-20220907-14-4y9xj.jpg?ixlib=rb-1.1.0&rect=61%2C15%2C5076%2C3404&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many everyday food products are ultra-processed.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/top-view-various-kids-cereals-colorful-158083484">Jiri Hera/ Shutterstock</a></span></figcaption></figure><p>In countries such as the UK, US and Canada, ultra-processed foods now account for <a href="https://pubmed.ncbi.nlm.nih.gov/30744710/">50% or more</a> of calories consumed. This is concerning, given that these foods have been linked to a number of different health conditions, including a greater risk of <a href="https://pubmed.ncbi.nlm.nih.gov/33167080/">obesity</a> and various chronic diseases such as <a href="https://nutritionj.biomedcentral.com/articles/10.1186/s12937-020-00604-1">cardiovascular disease</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/35896436/">dementia</a>.</p>
<p>Ultra-processed foods are <a href="https://pubmed.ncbi.nlm.nih.gov/30744710/">concoctions of various industrial ingredients</a> (such as emulsifiers, thickeners and artificial flavours), amalgamated into food products by a series of manufacturing processes.</p>
<p>Sugary drinks and many breakfast cereals are ultra-processed foods, as are more recent innovations, such as so-called <a href="https://www.sciencedirect.com/science/article/pii/S2213453019301144,">“plant-based” burgers</a>, which are typically made of protein isolates and other chemicals to make the products palatable.</p>
<p>The intense industrial processes used to produced ultra-processed foods destroy the <a href="https://pubmed.ncbi.nlm.nih.gov/35067754/">natural structure</a> of the food ingredients and strip away many beneficial nutrients such as fibre, vitamins, minerals and phytochemicals. </p>
<p>Many of us are well aware that ultra-processed foods are harmful for our health. But it’s been unclear if this is simply because these foods are of poor nutritional value. Now, two new studies have shown that poor nutrition may not be enough to explain their health risks. This suggests that other factors may be needed to fully explain their health risks. </p>
<h2>The role of inflammation</h2>
<p>The <a href="https://www.bmj.com/content/378/bmj-2022-070688">first study</a>, which looked at over 20,000 health Italian adults, found that participants who consumed the highest number of ultra-processed foods had an increased risk of dying prematurely from any cause. The <a href="https://www.bmj.com/content/378/bmj-2021-068921">second study</a>, which looked at over 50,000 US male health professionals, found high consumption of ultra-processed foods was associated with a greater risk of colon cancer.</p>
<p>What’s most interesting about these studies is that the health risks from eating a diet high in ultra-processed foods remained even after they had accounted for the poor nutritional quality of their diets. This suggests that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8747015/">other factors</a> contribute to the harms caused by ultra-processed foods.</p>
<p>It also implies that getting the right nutrients elsewhere in the diet may not be enough to cancel out the risk of disease from consuming ultra-processed foods. Similarly, attempts by the food industry to improve the nutritional value of ultra-processed foods by adding a few more vitamins may be side-stepping a more fundamental problem with these foods.</p>
<p>So what factors may explain why ultra-processed foods are so harmful to our health?</p>
<p>The Italian study found that inflammatory markers – such as a higher white blood cell count – were higher in groups that ate the most ultra-processed foods. Our bodies may trigger an inflammatory response for any number of reasons – for example, if we catch a cold or get cut. The body responds by sending signals to our immune cells (such as white blood cells) to attack any invading pathogens (such as bacteria or viruses).</p>
<p>Usually, our inflammatory response resolves quite quickly, but some people may develop chronic inflammation throughout their body. This can cause tissue damage, and is involved in many chronic diseases – such as <a href="https://pubmed.ncbi.nlm.nih.gov/25859884/">cancer</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/28744020/">cardiovascular disease</a>. </p>
<p>Many studies have found that poor diets can increase inflammation in the body, and that this is linked to <a href="https://pubmed.ncbi.nlm.nih.gov/28744020/">higher risk</a> of chronic diseases. Given that signs of inflammation were seen in participants of the Italian study who ate the most ultra-processed foods, this could suggest that inflammation may contribute to why ultra-processed foods increase disease risk. Some food additives common in ultra-processed foods (such as emulsifiers and artificial sweeteners) also increase inflammation in the gut by causing <a href="https://pubmed.ncbi.nlm.nih.gov/29899036/">changes to the gut microbiome</a>. </p>
<figure class="align-center ">
<img alt="A person drinks a glass of cola." src="https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483264/original/file-20220907-4832-n40bjw.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">Ultra-processed food products may even change our gut microbiome.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-drinking-glass-cola-ice-619622795">nednapa/ Shutterstock</a></span>
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<p>Some researchers have theorised that ultra-processed foods increase inflammation because they are recognised by the body as foreign – much like an invading bacteria. So the body mounts an inflammatory response, which has been dubbed “<a href="https://pubmed.ncbi.nlm.nih.gov/24939238/">fast food fever</a>”. This increases inflammation throughout the body as a result.</p>
<p>Although the US colon cancer study did not establish if inflammation increased in the men consuming the most ultra-processed foods, inflammation is strongly linked with an <a href="https://pubmed.ncbi.nlm.nih.gov/27821485/">increased risk of colon cancer</a>.</p>
<p>Research shows that other mechanisms – such as <a href="https://www.bmj.com/content/378/bmj-2022-070688">impaired kidney function</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/19502515/">toxins in packaging</a> – may also explain why ultra-processed foods cause so many dangerous health problems.</p>
<p>Since inflammatory responses are hard-wired in our bodies, the best way to prevent this from happening is by not eating ultra-processed foods at all. Some plant-based diets high in natural, unprocessed foods (such as the <a href="https://pubmed.ncbi.nlm.nih.gov/36039924/">Mediterranean diet</a>) have also been shown to be anti-inflammatory. This may also explain why plant-based diets free from ultra-processed foods can help ward off <a href="https://pubmed.ncbi.nlm.nih.gov/26148921/">chronic diseases</a>. It’s currently not known to what extent an anti-inflammatory diet can help counteract the effects of ultra-processed foods. </p>
<p>Simply reducing your intake of ultra-processed foods may be a challenge. Ultra-processed foods are designed to be hyper-palatable – and together with persuasive marketing, this can make resisting them an enormous challenge for <a href="https://pubmed.ncbi.nlm.nih.gov/33153827/">some people</a>.</p>
<p>These foods are also not labelled as such on food packaging. The best way to identify them is by looking at their ingredients. Typically, things such as emulsifiers, thickeners, protein isolates and other industrial-sounding products are a sign it’s an ultra-processed food. But making meals from scratch using natural foods is the best way to avoid the harms of ultra-processed foods.</p><img src="https://counter.theconversation.com/content/189918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Hoffman is the author of three books on the Mediterranean diet: The Mediterranean Diet: Health and Science (2011), More Healthy Years - Why a Mediterranean Diet is best for you and for the planet (2020) and Implementing the Mediterranean diet (2022).</span></em></p>Over half of all calories consumed in the UK are from an ultra-processed food product.Richard Hoffman, Associate lecturer, Nutritional Biochemistry, University of HertfordshireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1686452021-10-04T19:02:43Z2021-10-04T19:02:43ZWhy prescription drugs can work differently for different people<figure><img src="https://images.theconversation.com/files/424091/original/file-20210930-20-1owddsq.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Genetic differences, drug interactions and inflammation can affect how well drugs work in the body.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/physician-consulting-female-patient-about-pills-royalty-free-image/1207517989">ronstick/iStock via Getty Images Plus</a></span></figcaption></figure><p>Different people taking the same drug can have <a href="https://doi.org/10.1146/annurev.pharmtox.37.1.269">markedly different responses</a> to the same dose. While many people will get the intended effects, some may get little to no benefit, and others may get unwanted side effects.</p>
<p>As a <a href="https://pharmacy.uconn.edu/person/c-michael-white/">pharmacist</a> who <a href="https://scholar.google.com/citations?user=lWAD9d8AAAAJ&hl=en">researches the safety and effectiveness of drugs</a>, I know there are several reasons why this occurs, including individual physical differences, drug interactions and <a href="https://doi.org/10.1177/10600280211022281">inflammation</a>.</p>
<h2>Genetic differences</h2>
<p>The liver has a collection of enzymes called the <a href="https://doi.org/10.1146/annurev.pharmtox.37.1.269">cytochrome P450</a> system that metabolize, or break down, many drugs so they can be removed from the body. </p>
<p>The DNA, or genetic material, of cells contain the blueprint on how to create these enzymes. Unfortunately, some people have small errors in their DNA called <a href="https://doi.org/10.1089/gtmb.2016.0304">polymorphisms</a> that result in enzymes that don’t work as well.</p>
<p><a href="https://doi.org/10.1146/annurev.pharmtox.37.1.269">Where these errors</a> show up in the enzyme matter. If they occur in parts of the enzyme that aren’t directly involved in drug breakdown, they will have little effect on how well you metabolize a drug. Errors affecting the enzyme’s <a href="https://doi.org/10.1042/BST20170218">active site</a> that binds to drugs, however, can cripple its ability to break down a drug and subsequently mean there’s <a href="https://doi.org/10.1177/10600280211022281">more of the drug circulating in the blood</a>. If the rising blood concentration <a href="https://doi.org/10.1186/s12874-017-0363-z">exceeds the drug’s therapeutic range</a>, serious side effects can occur.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of enzyme binding process." src="https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424266/original/file-20211001-18-1vctpc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Enzymes can only break down drugs when they bind to their active sites.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/enzyme-vector-illustration-labeled-cycle-and-royalty-free-illustration/1061592944">VectorMine/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Some people have a polymorphism that instructs their body to create two of the same enzyme instead of just one. These “<a href="https://doi.org/10.1186/1559-0275-8-12">ultrametabolizers</a>” break down drugs faster than normal, resulting in a lower concentration of active drug in their bodies. If the concentration falls below the therapeutic range, there may not be enough drug for a beneficial effect.</p>
<p>Clinicians can test patients’ DNA for these enzyme polymorphisms. If a known polymorphism is detected, they can <a href="https://doi.org/10.1186/1559-0275-8-12">alter the dose</a> or avoid certain drugs altogether if they don’t work as well as they should or are more likely to cause side effects.</p>
<h2>Drug interactions</h2>
<p>Genetic variability only explains a portion of the variability in drug response. Another factor to consider is <a href="https://dx.doi.org/10.1080%2F08998280.2000.11927719">drug interactions</a>.</p>
<p>Some drugs block the active site of the liver enzyme cytochrome P450 so it can’t be reused, preventing other drugs from binding to it and getting metabolized. As drug concentrations rise, so does the risk of side effects. For example, the heart rhythm drug amiodarone can block <a href="https://www.pharmacytimes.com/view/2008-03-8462">metabolism of the blood thinner warfarin</a>, which results in very high warfarin concentrations that could lead to life-threatening bleeding.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of competitive inhibition in enzymes." src="https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424080/original/file-20210930-16-cvhhd2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some drugs directly bind to the active site of an enzyme and close it off to other drugs.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/competitive-inhibition-enzyme-inhibitor-is-a-royalty-free-illustration/1159659393">ttsz/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Conversely, the antiepilepsy drugs phenytoin and carbamazepine can <a href="https://dx.doi.org/10.1080%2F08998280.2000.11927719">stimulate production of even more metabolic enzymes</a> than usual. Other drugs may be metabolized faster than usual, and their beneficial effects may be lost.</p>
<h2>Inflammation</h2>
<p>When the body is newly infected or injured, the <a href="https://doi.org/10.1177/1060028020922994">inflammatory response</a> brings white blood cells and increased blood flow to the area to sterilize and repair the problem. Inflammation is meant to <a href="https://doi.org/10.1177/1060028018765939">last for only short periods of time</a>. But the immune systems of some people may also attack unaffected areas and result in chronic inflammation that can damage tissues and joints, or even increase the <a href="https://doi.org/10.1177/1060028020922994">risk of heart disease</a>.</p>
<p><a href="https://doi.org/10.1177/1060028020922994">Inflammation</a> from a <a href="https://doi.org/10.1177/10600280211047864">new infection or chronic inflammatory disease</a> like rheumatoid arthritis or psoriasis could also impair how well enzymes like cytochrome P450 can metabolize drugs. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/FXSuEIMrPQk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The inflammatory response is one way the immune system reacts to injury or disease.</span></figcaption>
</figure>
<p>In addition to producing cytochrome P450 enzymes, the liver is one of the major organs that create special proteins called <a href="https://doi.org/10.1177/10600280211022281">cytokines and interferons</a> that participate in the <a href="https://doi.org/10.1038/cmi.2016.3">immune response</a>. When the liver is busy making all of these proteins, it does not have the capacity to make as many drug-metabolizing enzymes, which results in a decline in drug break down. When the infection goes away or the source of inflammation is blocked with anti-inflammatory drugs, however, the liver’s ability to metabolize drugs <a href="https://doi.org/10.1177/10600280211022281">goes back to normal</a>. This means that someone with an <a href="https://doi.org/10.1177/10600280211047864">infection or chronic inflammation</a> might need a lower dose of drug than normal since their liver enzymes aren’t clearing them as quickly as usual. And when that <a href="https://doi.org/10.1177/10600280211022281">inflammation is resolved</a>, they may need to increase their dose to maintain the same desired effects they had before. </p>
<p>One of the prime ways to see if you have increased inflammation is by checking your <a href="https://doi.org/10.1177/1060028020922994">c-reactive protein (CRP)</a> concentration. While CRP doesn’t directly cause inflammation, the body produces more CRP as a result of inflammation. So a higher CRP level in the blood could indicate underlying inflammation and, subsequently, <a href="https://doi.org/10.1177/10600280211047864">increased suppression</a> of drug metabolism. </p>
<h2>Other factors affecting drug metabolism</h2>
<p>Even if drug interactions are avoided and inflammation is kept in check, there are many other factors that can influence drug effects. </p>
<p><a href="https://dx.doi.org/10.2147%2FDDDT.S246229">Liver or kidney damage</a> could reduce how well drugs are broken down and eventually expelled in the urine or bile. </p>
<p>Body size also affects drug response. Drug concentration in the body is determined by both the dose given and the volume of an individual’s body fluids. Giving the same drug dose to a <a href="https://doi.org/10.1080/17425255.2018.1440287">smaller-sized person</a> could cause a higher blood concentration than when given to a larger person. This is why many drugs are given in lower doses to children than adults.</p>
<p>And finally, some people either don’t <a href="https://doi.org/10.1177/1074248418769040">have many receptors</a> in their body for the drug to bind to and produce its effects, or the receptors that they do have don’t work well. This could be due to genetic mutations or underlying disease. An average dose of a drug would only produce a limited response in these patients.</p>
<h2>Talk to your clinician</h2>
<p>One reason why there are so many types of drugs and available doses for different diseases is because your response to the drug might not be the same as the average person’s. When you start a new drug regimen, it might have to be adjusted to the right level, and that will take patience and cooperation between you and your clinician. </p>
<p>To identify any potential drug interactions, <a href="https://doi.org/10.1177/1060028013511786">tell your pharmacist</a> all the prescription, over-the-counter and dietary supplement products you are taking.</p>
<p>If you develop a new infection or disease that causes inflammation, the dosages of the others drugs you are currently taking <a href="https://doi.org/10.1177/10600280211047864">might need to be reduced</a>. If you notice new side effects, let your clinician or pharmacist know right away.</p>
<p>If you have a severe chronic inflammatory disease like rheumatoid arthritis or psoriasis and start a potent anti-inflammatory drug, let your clinician or pharmacist know if the other drugs you’re taking <a href="https://doi.org/10.1177/10600280211022281">aren’t working as well as before</a> so your dose can be adjusted.</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/168645/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C. Michael White 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>The same dose of a drug can have varying degrees of effectiveness and safety depending on how well the liver can metabolize it.C. Michael White, Distinguished Professor and Head of the Department of Pharmacy Practice, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/151732013-07-23T20:11:57Z2013-07-23T20:11:57ZExplainer: what is inflammatory bowel disease?<figure><img src="https://images.theconversation.com/files/27911/original/kv5ygnkb-1374563238.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Inflammatory bowel disease is one of a variety of unrelated but ongoing gastrointestinal disorders.</span> <span class="attribution"><span class="source">J.B. Hill</span></span></figcaption></figure><p><a href="http://www.cdc.gov/ibd/">Inflammatory bowel disease</a> is a group of inflammatory conditions of the colon and small intestine that can cause life-threatening complications and may require surgery. Luckily, current therapies offer real benefits and there are some <a href="http://www.mayoclinic.org/medicalprofs/ibd-pipeline-drugs-pudd0412.html">promising drugs</a> in the pipeline.</p>
<p>The disease is one of a variety of unrelated but ongoing gastrointestinal disorders. Of these, some of the most common complaints are about gluten intolerance and functional bowel problems (when the gut doesn’t work properly, such as when someone has irritable bowel syndrome). Crohn’s disease and ulcerative colitis are examples of inflammatory bowel disease. </p>
<p>All of these problems have very different causes, although having one of them may put you at an increased risk of developing another.</p>
<h2>Causes and effects</h2>
<p>The precise causes of inflammatory bowel disease <a href="http://www.med.unc.edu/gi/specialties/ibd/about-ibd/what-causes-inflammatory-bowel-diseases-ibd">are not known</a>. What we do know is that, in general, people with inflammatory bowel disease are likely to have a genetic predisposition for the disease. Their genes make it more likely that they will develop inflammatory bowel disease although they may never do so. </p>
<p>If they develop the disease, it’s most likely because of an environmental trigger – stress, for instance, or malnutrition or certain drugs. But, in most people, the trigger may never be known. </p>
<p>Factors in the gut, such as a disruption in the balance between good and bad bacteria, can also contribute to the onset of the disease.</p>
<p>The effect of inflammatory bowel disease on the gut is actually caused by the person’s immune system. Once activated, the disease attacks the body’s cells instead of foreign cells such as bacteria, fungi or viruses. </p>
<p>This initiates the sort of angry red inflammation in the gut that would normally get rid of infections. Unfortunately, in the case of inflammatory bowel disease, the immune system reacts to bacteria that are normally resident in the gut. And, in so doing, the disease causes severe damage that can cause a perforation (a hole through the wall of the gut). </p>
<p>This is a life-threatening event and, at this point, surgery is the only treatment option. The many surgeries some people suffering from inflammatory bowel disease have to undergo during their life is extremely burdensome. </p>
<p>But there’s an indirect benefit for the community in this – the resulting surgical samples can sometimes be used to help researchers who are trying to find a cure for inflammatory bowel disease.</p>
<h2>Current and new treatments</h2>
<p>Inflammatory bowel disease is not active all the time – it is prone to flare-ups that are separated by quiet times during which the disease is in remission. This makes treatment more complicated because it can be hard to know if the remission is caused by a new drug or if it’s spontaneous. </p>
<p>Most cases of inflammatory bowel disease are initially handled by giving the sufferer an anti-inflammatory drug that will hopefully induce remission. Once in remission, many patients take immunosuppressant drugs that decrease the likelihood of another flare-up. </p>
<p>Immunosuppressants are drugs that modify how the immune system works and generally lower its activity. Many new drugs that fall into this general class are being developed. </p>
<p>With the immune attack reduced, the gut can often heal on its own and stay healthy for longer. Current treatment strategies generally start with older drugs but if these fail, <a href="http://en.wikipedia.org/wiki/Biological_therapy_for_inflammatory_bowel_disease">biological therapies</a>, such as infliximab, are tried. A biological therapy also targets the immune system. The active compounds often originate from human, animal or bacterial sources - for example, infliximab is an antibody. </p>
<p>These drugs are effective in many people but they can have severe side-effects and become less effective over time.</p>
<p><a href="http://www.nature.com/nrd/journal/v12/n6/full/nrd4037.html">Three new such drugs</a> (all using the same approach) are currently undergoing the lengthy regulatory approval process overseas. They inhibit a protein in the body called an “integrin”, which helps cells stick together. In inflammatory bowel disease, the integrins are what allow immune cells to invade the intestine and start the inflammatory process.</p>
<p>The role of integrins has been known for many years, but the problem is that they are located everywhere in the body. Drugs that block all integrins are dangerous for various reasons, for example, because blood clotting is dependent on integrins. </p>
<p>These new drugs block only one specific type of integrin and seem to be safe and effective. They target a kind of integrin that is only found on some white blood cells that are crucial for an immune response in inflammatory bowel disease. </p>
<p>To date, these drugs have been mainly tested on patients who have already failed using current therapies. There’s hope that once these drugs are registered, they will find an earlier use in less severely affected patients.</p>
<p>It’s likely that one or more of these new drugs will get regulatory approval before long, but it may be another four or five years before they would be prescribed to patients. Clinical trials to monitor their safety and effectiveness will be required first.</p><img src="https://counter.theconversation.com/content/15173/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Bertrand receives funding from National Health and Medical Research council for projects relating to gastrointestinal health.</span></em></p><p class="fine-print"><em><span>Lu Liu receives funding from National Health and Medical Research Council.</span></em></p>Inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine that can cause life-threatening complications and may require surgery. Luckily, current therapies offer…Paul Bertrand, Senior Lecturer in School of Medical Sciences, RMIT UniversityLu Liu, Senior Lecturer in Pharmacology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/30902011-10-10T19:39:47Z2011-10-10T19:39:47ZHelp or hindrance? Antibiotics’ role in chronic inflammatory diseases<figure><img src="https://images.theconversation.com/files/4284/original/NOVAMOXIN_antibiotic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Antibiotics' ability to kill gut germs could be contributing to the rise of chronic inflammatory diseases. </span> <span class="attribution"><span class="source">Bmramon/Wikimedia Commons</span></span></figcaption></figure><p>We sometimes forget that antibiotics kill beneficial microorganisms as well as those that threaten our health. In fact, the damage they wreak on “good” germs could be responsible for the growth of certain types of diseases in modern society. </p>
<p>The complex ecosystem of microbes within our guts – our gut “microbiome” – is absolutely essential for health and our use of antibiotics could be permanently injuring it.</p>
<p>In <a href="http://www.nature.com/nature/journal/v476/n7361/full/476393a.html">recent commentary</a> published in <a href="http://www.nature.com/">Nature</a> magazine, Dr Martin Blaser highlighted several such unintended consequences of antibiotic use. </p>
<p>Dr Blaser suggests antibiotic use is killing beneficial bacteria, leading to permanent loss of protective flora. He suggests this may be fuelling the dramatic increase in chronic inflammatory conditions such as obesity, type 1 diabetes, inflammatory bowel disease, allergies and asthma.</p>
<p>Blaser supports his argument by presenting data from a <a href="http://gut.bmj.com/content/60/1/49.abstract">recent Danish study</a> that showed a three-fold increase in inflammatory bowel disease (IBD) in children who had received seven or more courses of antibiotics, compared with children who had received none. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=565&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=565&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=565&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=710&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=710&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4289/original/5693290240_a4f42f6f2f_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=710&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Not all bacteria are harmful.</span>
<span class="attribution"><span class="source">AJC1</span></span>
</figcaption>
</figure>
<p>Importantly, the effect was almost twice as strong for antibiotics taken less than three months before the onset of IBD. </p>
<p>This suggests a link between inflammatory bowel disease and antibiotics, but this link may be one in which the antibiotics act as a disease trigger rather than a risk factor. </p>
<p>An easy way to understand the difference between a trigger and a risk factor is to think about someone with high blood pressure who has a heart attack while competing in a fun run. </p>
<p>High blood pressure is a risk factor and the trigger is the added stress on the heart caused by running. </p>
<p>In the case of inflammatory bowel disease, in which the immune system has an inappropriate response to gut bacteria, it can be difficult to distinguish between the role of individual bacteria as targets of the response (that is, triggers) and the role of the entire gut bacterial ecosystem as a factor in protecting against IBD.</p>
<p>But the three-fold change in IBD rates, while statistically significant, can explain only a small part of the 15-fold increase in IBD cases in Denmark in the last 30 years. </p>
<p>We urgently need to understand other environmental risk factors that have produced such a profound increase. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4288/original/4533589633_0507d84ee3_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The hygiene hypothesis suggests birth order is key to avoiding allergies.</span>
<span class="attribution"><span class="source">Charlotta Wasteson</span></span>
</figcaption>
</figure>
<p>One explanation for the rising rates of allergic and inflammatory diseases is the <a href="http://www.ncbi.nlm.nih.gov/pubmed/2513902?dopt=Citation">hygiene hypothesis, formulated by Dr David Strachan</a> in 1989. </p>
<p>Strachan, who was the first to suggest a role for microbes in protecting against allergy, concluded that “allergic diseases were prevented by infection in early childhood, transmitted by unhygienic contact with older siblings, or acquired prenatally from a mother infected by contact with her older children.” </p>
<p>His analysis of hay fever rates in the United Kingdom showed birth order alone had a four-fold effect on hay fever and eczema. </p>
<p>Since the effect was seen within families sharing the same living conditions, Strachan’s analysis ruled out many factors commonly blamed for allergies, such as pollution, processed food and vaccinations. </p>
<p>Colonisation of the gut by microbes in early life may be the “infection in early childhood” that explains Strachan’s birth order effect. </p>
<p>These gut microbes can be killed by antibiotics, leaving the immune system acutely vulnerable to inflammatory diseases such as IBD. But the gut microbiome usually rebounds with time and is <a href="http://www.ncbi.nlm.nih.gov/pubmed/20847294">remarkably resilient in the long term</a> unless exposed to multiple courses of antibiotics.</p>
<p>But if beneficial gut microbes are never transmitted to babies in the first place, then the negative effect will be far more severe in response to later antibiotic treatment.</p>
<p>We need to ensure conditions are ideal for transmission of beneficial microbial ecosystems from mother to baby. This could be done by recognising that, for instance, caesarean-section births prevent normal colonisation of the baby’s gut. </p>
<p>We also need to understand how the interaction of a healthy microbiome with the immune system prevents diseases such as allergies, type 1 diabetes and IBD.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4286/original/2447205771_1f3517551c_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Caesarean-section births prevent normal colonisation of the baby’s gut.</span>
<span class="attribution"><span class="source">Hryck</span></span>
</figcaption>
</figure>
<p><a href="http://theconversation.com/how-clean-is-too-clean-trust-your-gut-instincts-855">My research at Sydney’s Centenary Institute</a> has indicated the crucial link between the microbiome and the immune system may be via a small subset of immune cells called regulatory T cells. </p>
<p>We are now working to understand how regulatory T cells read cues from the microbiome. </p>
<p>Our aim is to build a picture of the ideal microbiome required for immune health to ensure that every child starts life with the best possible chance of achieving long-term immune health, free of allergy, autoimmunity and inflammatory disease.</p><img src="https://counter.theconversation.com/content/3090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Barbara Fazekas de St Groth receives funding from ARC and NHMRC.</span></em></p>We sometimes forget that antibiotics kill beneficial microorganisms as well as those that threaten our health. In fact, the damage they wreak on “good” germs could be responsible for the growth of certain…Barbara Fazekas de St Groth, Professor of Immunology, Centenary InstituteLicensed as Creative Commons – attribution, no derivatives.