117 | id == 117
117 | category_id == 16
117 | category_order == 13
117 | category_name == Gut Health
117 | category_color == #C47AC0
117 | slug == HTR3A-IBS
117 | title == The Impact of a Serotonin Receptor on IBS-D (HTR3A)
117 | meta_description == HTR3A codes for a piece of the 5-HT3 serotonin receptor. Which genetic variants may predispose people to IBS? Find out here.
117 | summary == <p><strong>HTR3A codes for a piece of the 5-HT3 serotonin receptor, which increases movement in the gut. Which genetic variants may predispose people to IBS? Find out here.</strong></p>
117 | overall_score_text == Gut Inflammation Score (based on HTR3A)
117 | image == https://sd-selfdecode-assets-prod.s3.amazonaws.com/blog/background/HTR3A--Gut-Inflammation-IBS.jpg
117 | author_id == 1
117 | author_name == Jasmine Foster
117 | author_title == BSc, BEd
117 | author_order == 36
117 | author_photo == https://sd-selfdecode-assets-prod.s3.amazonaws.com/blog/author-photo/Jasmine.jpg
117 | author_intro == <p><strong>Jasmine received her BS from McGill University and her BEd from Vancouver Island University.</strong></p>    <p>Jasmine loves helping people understand their brains and bodies, a passion that grew out of her dual background in biology and education. From the chem lab to the classroom, everyone has the right to learn and make informed decisions about their health.</p>
117 | reviewer == None
117 | medical_reviewer_id == 11
117 | medical_reviewer_name == Puya Yazdi
117 | medical_reviewer_title == MD
117 | publish_date == 2020
117 | publish_date == 3
117 | publish_date == 19
117 | avg_rating == 5.0
117 | tags_id == 310
117 | tags_name == 5-HT3 Receptor
117 | tags_id == 311
117 | tags_name == Diarrhea
117 | tags_id == 194
117 | tags_name == Gut Health
117 | tags_id == 308
117 | tags_name == Gut Inflammation
117 | tags_id == 320
117 | tags_name == HTR3A Gene
117 | tags_id == 8
117 | tags_name == IBS
117 | tags_id == 312
117 | tags_name == Nausea
117 | tags_id == 309
117 | tags_name == Serotonin
117 | permissions_favorite == False
117 | permissions_rate == False
117 | content_article == <h2><span style="font-weight: 400;">Serotonin and the Gut</span></h2> <p><span style="font-weight: 400;">Serotonin is best known as a neurotransmitter in the brain, and more specifically for its roles in mental health, reward, and happiness. However, serotonin plays myriad roles outside of the brain, as well, and it is essential for constriction and movement in the digestive system [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449495/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">In the gut, serotonin regulates the secretion of mucus and pancreatic enzymes and the absorption of fluids. It also regulates the movement of muscles in the gut, which in turn determines how quickly food passes through the intestine [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2694720/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/29909048"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Serotonin also plays a role in immune function and inflammation in the intestine. When serotonin is released into the gut, the secretion of inflammatory cytokines increases. Serotonin also increases the recruitment of white blood cells and platelets. Normally, this system helps kill pathogens and prevent them from crossing into the bloodstream; however, it can also lead to potentially dangerous inflammation [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2694720/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/29909048"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400; background-color: #e8ebfc; border-left: 2px solid #4569fa; display: block; padding: 20px;">In the gut, serotonin regulates inflammation, immunity, and the secretion of mucus and pancreatic enzymes.</span></p> <h2><span style="font-weight: 400;">What is </span><em><span style="font-weight: 400;">HTR3A</span></em><span style="font-weight: 400;">?</span></h2> <p><span style="font-weight: 400;">The </span><em><span style="font-weight: 400;">HTR3A </span></em><span style="font-weight: 400;">gene codes for a part of the 5-HT3 serotonin receptor. This is considered to be one of the three most important types of serotonin receptor in the gut (the others being 5-HT1b and 5-HT4) [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">The 5-HT3 receptor is scientifically interesting because it has a different structure from all other types of serotonin receptor. When the 5-HT3 receptor is activated, it causes nausea, vomiting, and anxiety. Increased activation of these receptors also appears to predispose people to seizures [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/25838122"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/books/NBK513318/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5771379/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">These receptors are present throughout the nervous system, both inside and outside the brain. It is also found in non-neuronal cells, especially white blood cells [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994432/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <h3><span style="font-weight: 400;">The 5-HT3 Receptor and IBS</span></h3> <p><span style="font-weight: 400;">Given the importance of serotonin in the gut and the function of 5-HT3 in nausea and vomiting, it&rsquo;s not surprising that this receptor is implicated in gut disorders like IBS.</span></p> <p><span style="font-weight: 400;">Many IBS patients have abnormal serotonin systems. Specifically, people with IBS tend to secrete more serotonin, which results in increased movement of the gut tissues, increased inflammation, and more white blood cells in the intestine [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692018/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Some IBS medications block 5-HT3 receptors and prevent the action of serotonin in the gut. In this way, they reduce excess movement of gut muscles and slow down the rate at which food passes through the intestines [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">However, 5-HT3 receptor blockers are only effective for some people with diarrhea-predominant IBS [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="background-color: #e8ebfc; border-left: 2px solid #4569fa; display: block; padding: 20px;"><em><span style="font-weight: 400;">HTR3A</span></em><span style="font-weight: 400;"> codes for one of the parts of the 5-HT3 serotonin receptor, which causes nausea, vomiting, and increased gut motility when activated. 5-HT3 receptor blockers are effective for some cases of IBS-D.</span></span></p> <h3><em><span style="font-weight: 400;">HTR3A </span></em><span style="font-weight: 400;">in People with IBS</span></h3> <p><span style="font-weight: 400;">In theory, variants in the 5-HT3 receptor that increase its activity could increase movement in the gut and increase susceptibility to IBS.</span></p> <p><span style="font-weight: 400;">One variant in the </span><em><span style="font-weight: 400;">HTR3A </span></em><span style="font-weight: 400;">gene has been directly linked to IBS. At rs1062613, the minor &lsquo;T&rsquo; allele was associated with increased rates of IBS and increased receptor activation [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5725034/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/18614545"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <h2><span style="font-weight: 400;">Your HTR3A Results for IBS</span></h2> <p>*2243488962267692*</p> <h3><span style="font-weight: 400;">SNP Summary and Table</span></h3> <p><strong>HTR3A rs1062613</strong></p> <ul> <li style="font-weight: 400;"><span style="font-weight: 400;">&lsquo;C&rsquo; = Normal HTR3A expression</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">&lsquo;T&rsquo; = Increased HTR3A expression, associated with increased rates of IBS</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">The &lsquo;TT&rsquo; genotype is much more common in people of African descent (26%) compared to the global population (9.2%).</span></li> </ul> <p>*9940696334195571*</p> <h2><span style="font-weight: 400;">Recommendations to Reduce Gut Disturbances</span></h2> <p><span style="font-weight: 400;">Certain lifestyle changes and supplements may help reduce 5-HT3 receptor activity and improve the symptoms of IBS. To avoid unexpected side effects, talk to your doctor before making any significant changes to your lifestyle or adding any new supplements.</span></p> <p>*4334528778929969*</p> <h3><span style="font-weight: 400;">Lifestyle</span></h3> <h4><span style="font-weight: 400;">Stress Reduction</span></h4> <p><span style="font-weight: 400;">Psychological stress is widely believed to trigger or worsen IBS. In fact, some researchers refer to both &ldquo;irritable bowel&rdquo; and &ldquo;irritable brain&rdquo; as equal factors in the development of IBS. Furthermore, anxiety and frustration with gut symptoms can further worsen these same symptoms. As such, many experts recommend stress management strategies as part of a holistic strategy to manage and treat this condition [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4202343/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692018/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/28061975"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">The precise relationship between 5-HT3 receptors and psychological stress hasn&rsquo;t yet been fully unraveled in humans. However, in animals, blocking 5-HT3 receptors helps reduce depressive behavior and the sensation of pain [</span><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909071"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/24741192"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4625078/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3801375/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <h3><span style="font-weight: 400;">Supplements</span></h3> <h4><span style="font-weight: 400;">Herbal Supplements</span></h4> <p><span style="font-weight: 400;">A number of plant-derived compounds have been found to antagonize the 5-HT3 receptor. Many of these are currently under investigation for their potential to reduce chemotherapy-induced nausea and vomiting, but they may also be helpful in some cases of IBS [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321066/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Menthol, an active compound in </span><a href="https://selfhacked.com/blog/peppermint-oil-benefits-uses-side-effects/"><span style="font-weight: 400;">peppermint</span></a><span style="font-weight: 400;">, is among the herbal compounds found to block the 5HT3 receptor [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321066/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Peppermint is among the best-known and -studied natural remedies for IBS, and it has a significant chunk of evidence to back up its use. A meta-analysis of twelve studies and 835 patients found that peppermint oil reduced abdominal pain and other symptoms of IBS without adverse effects [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6337770/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Other active compounds that block the 5-HT3 receptor include capsaicin (found in hot peppers), eugenol (found in cloves and holy basil), vanillin (found in vanilla), thujone (found in thyme and sage), cannabidiol (extracted from cannabis), and several compounds in ginger [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321066/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Of these, ginger, capsaicin, eugenol, and cannabidiol have also shown some potential in clinical studies of patients with IBS [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341159/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4102147/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/25473818"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/books/NBK425767/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400; background-color: #e8ebfc; border-left: 2px solid #4569fa; display: block; padding: 20px;">Many herbs contain compounds that can block the 5-HT3 receptor. The best-studied of these in IBS is peppermint.</span></p> <h4><span style="font-weight: 400;">Probiotics</span></h4> <p><span style="font-weight: 400;">One of the most likely causes of IBS is dysregulation of the gut flora. In fact, individuals with IBS often appear to have decreased diversity and numbers of beneficial </span><a href="https://selfhacked.com/blog/how-your-gut-microbiota-can-make-you-fat-or-thin/"><span style="font-weight: 400;">microbiota</span></a><span style="font-weight: 400;"> and protective strains such as </span><a href="https://selfhacked.com/blog/l-reuteri/"><em><span style="font-weight: 400;">L. reuteri</span></em></a><span style="font-weight: 400;"> [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039952/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Fermented foods are a great way to increase your intake of diverse probiotic bacteria without the use of supplements. Consuming fermented milk products (which include buttermilk, cheese, yogurt, kefir, sour cream, and more) significantly improved symptoms of IBS in multiple clinical trials [</span><a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2036.2008.03818.x"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2036.2007.03362.x"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">Another fermented food with promise for IBS is sauerkraut (a type of fermented cabbage) [</span><a href="https://www.ncbi.nlm.nih.gov/pubmed/30256365"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723656/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400;">There is some laboratory evidence that acetate, which is produced by healthy gut flora, reduces the expression of the 5-HT3 receptor in intestinal tissues; this result suggests that certain acetate-producing probiotics may be helpful for those with problematic </span><em><span style="font-weight: 400;">HTR3A </span></em><span style="font-weight: 400;">variants. However, this has not yet been studied in humans [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538830/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p> <p><span style="font-weight: 400; background-color: #e8ebfc; border-left: 2px solid #4569fa; display: block; padding: 20px;">Certain bacteria in the healthy gut flora may help suppress the expression of the 5-HT3 receptor in the gut.</span></p> <h3><span style="font-weight: 400;">Drugs</span></h3> <p><span style="font-weight: 400;">Some 5-HT3R receptor antagonists such as Alosetron and Cilansetron are available to treat diarrhea-predominant IBS. If you have severe IBS-D, your doctor may consider prescribing these medications. However, you should never take any medication without your doctor&rsquo;s recommendation or prescription [</span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503665/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">, </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479009/"><span style="font-weight: 400;">R</span></a><span style="font-weight: 400;">].</span></p>
117 | content_snp_table_2243488962267692_key == 2243488962267692
117 | content_snp_table_2243488962267692_blur == True
117 | content_snp_table_2243488962267692_hidden == False
117 | content_learn_more_9940696334195571_key == 9940696334195571
117 | content_learn_more_9940696334195571_blur == True
117 | content_learn_more_9940696334195571_hidden == False
117 | content_learn_more_9940696334195571_text == Based on the variants we looked at, your HTR3A gene may slightly increase your predisposition toward IBS-D. However, this doesn't necessarily reflect your overall risk of IBS-D, just one gene related to it. Stress reduction, probiotics, and herbal supplements may help. Keep scrolling to find out more.
117 | content_recommendation_4334528778929969_key == 4334528778929969
117 | content_recommendation_4334528778929969_blur == True
117 | content_recommendation_4334528778929969_hidden == False
rsIDs = rs1062613
rsStatus = rs1062613,HTR3A,chr11,113975284,T,C,,,13,20,HET
