{"id":82,"date":"2025-11-20T20:44:24","date_gmt":"2025-11-21T01:44:24","guid":{"rendered":"https:\/\/resources.aspergerworks.org\/?p=82"},"modified":"2025-12-10T15:43:08","modified_gmt":"2025-12-10T20:43:08","slug":"connection-between-the-microbiome-and-autism","status":"publish","type":"post","link":"https:\/\/resources.aspergerworks.org\/?p=82","title":{"rendered":"Connection Between the Microbiome and Autism"},"content":{"rendered":"\n[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; custom_margin=&#8221;-27px|||||&#8221; custom_padding=&#8221;7px||0px|||&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_row _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; custom_margin=&#8221;1px|auto||auto||&#8221; custom_padding=&#8221;9px|35px||||&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_heading title=&#8221;once you account for weak methods and flawed assumptions, \u201cthere\u2019s nothing there.\u201d&#8221; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; custom_padding=&#8221;||7px|||&#8221; global_colors_info=&#8221;{}&#8221;][\/et_pb_heading][et_pb_text _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; custom_margin=&#8221;-31px|||||&#8221; global_colors_info=&#8221;{}&#8221;]<p>The idea that autism is closely linked to gut bacteria has recently gotten a lot of attention. A major research funder (<a href=\"https:\/\/wellcomeleap.org\/\" target=\"_blank\" rel=\"noopener\" title=\"Wellcome Leap\">Wellcome Leap<\/a>) just announced a $50 million call for projects, and a 2024 Netflix documentary suggests that fecal transplants could help with autism traits.<\/p>\n<p>But <a href=\"https:\/\/www.tcd.ie\/research\/profiles\/?profile=KEMITCHE\" target=\"_blank\" rel=\"noopener\" title=\"Kevin Mitchell\">Kevin Mitchell<\/a>, a genetics and neuroscience professor in Dublin, says he\u2019s been skeptical for years. He and several colleagues were so frustrated by the hype that they reviewed more than 30 studies on the topic\u2014mouse studies, human observational research, and clinical trials\u2014and published their findings in <em><a href=\"https:\/\/www.cell.com\/neuron\/home\" target=\"_blank\" rel=\"noopener\" title=\"Neuron\">Neuron<\/a><\/em>. Their conclusion: once you account for weak methods and flawed assumptions, \u201cthere\u2019s nothing there.\u201d<\/p>\n<p>Despite this, U.S. federal agencies have been investing about $20\u2013$25 million per year in autism\u2013microbiome research since 2018. Mitchell worries that funders assume the field rests on solid science when it doesn\u2019t.<\/p>\n<p>Mitchell walked <em><a href=\"https:\/\/www.thetransmitter.org\/\" target=\"_blank\" rel=\"noopener\" title=\"The Transmitter\">The Transmitter<\/a><\/em> through the major problems he sees in this research:<\/p>\n<ul>\n<li><strong> \u201cQuasi-replication\u201d:<\/strong><br \/>Different studies claim to show microbiome differences in autistic people, but the actual results often contradict each other. Referring to broad \u201cdysbiosis\u201d (an imbalance of microorganisms in the body, particularly in the gut, where beneficial microbes are reduced and harmful ones may increase) masks the fact that findings don\u2019t align, which should <em>lower<\/em> confidence, not raise it.<\/li>\n<li><strong> Too much analytical freedom:<\/strong><br \/>With hundreds of bacterial species and many ways to slice the data, researchers can almost always find <em>something<\/em> different, even by accident. Such exploratory findings should be treated as preliminary, not as proof.<\/li>\n<li><strong> Better-designed sibling studies show no differences:<\/strong><br \/>The strongest observational studies compare autistic people to their neurotypical (describes\u00a0a brain that functions and develops in a way considered standard within society) siblings, who share genes, diet, and home environment. These studies find little to no differences in microbiomes (communities of microorganisms, such as bacteria, fungi, and viruses, that live in a specific environment, including the human body). Machine-learning studies also fail when siblings are used as controls, suggesting that earlier \u201csignals\u201d may have come from confounding factors such as diet.<\/li>\n<li><strong> Sample sizes are far too small:<\/strong><br \/>Extensive microbiome studies on other conditions require thousands of participants to detect real effects. Many autism\u2013microbiome studies include only 10\u201320 people\u2014numbers that generate noise rather than reliable results.<\/li>\n<li><strong> Mouse models are unreliable:<\/strong><br \/>Germ-free mice already show \u201cautism-like\u201d behaviors, making it unclear what\u2019s being tested. Human gut bacteria usually do not survive in mouse guts. And the idea of \u201cautistic-like\u201d mouse behavior isn\u2019t well validated in the first place.<\/li>\n<li><strong> Clinical trials don\u2019t support fecal transplants:<\/strong><br \/>Three small, uncontrolled studies reported significant improvements, but these designs can\u2019t rule out placebo effects or natural development over time. A larger, well-controlled study found no benefit.<\/li>\n<\/ul>\n<p><strong>Why does the idea persist? <\/strong><\/p>\n<p>Mitchell says people want a simple, treatable explanation for autism\u2014a clean story that makes a complex condition feel manageable.<\/p>\n<p>His advice for researchers, journalists, and funders: <strong>read the actual studies, not just the headlines<\/strong>, and be cautious about investing time, attention, and money in a field with so little solid evidence. (For the interview, see <a href=\"https:\/\/www.thetransmitter.org\/spectrum\/going-against-gut-qa-kevin-mitchell-autism-microbiome-theory\/\" target=\"_blank\" rel=\"noopener\" title=\"Going against the gut: Q&amp;A with Kevin Mitchell on the autism-microbiome theory\"><strong><em>Going against the gut: Q&amp;A with Kevin Mitchell on the autism-microbiome theory<\/em> <\/strong><\/a>by <a href=\"https:\/\/www.thetransmitter.org\/contributor\/lauren-schenkman\/\" target=\"_blank\" rel=\"noopener\" title=\"Lauren Schenkman\">Lauren Schenkman<\/a>, contributing writer at The Transmitter.)<\/p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]\n","protected":false},"excerpt":{"rendered":"<p>The idea that autism is closely linked to gut bacteria has recently gotten a lot of attention. A major research funder (Wellcome Leap) just announced a $50 million call for projects, and a 2024 Netflix documentary suggests that fecal transplants could help with autism traits. But Kevin Mitchell, a genetics and neuroscience professor in Dublin, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":178,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","_crdt_document":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6,27,28,12],"tags":[],"class_list":["post-82","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-autism","category-genetics","category-neuroscience","category-scientific-studies","et-has-post-format-content","et_post_format-et-post-format-standard"],"jetpack_featured_media_url":"https:\/\/resources.aspergerworks.org\/wp-content\/uploads\/2025\/11\/Mitchell-Microbiome-autism-1200.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/posts\/82","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=82"}],"version-history":[{"count":9,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/posts\/82\/revisions"}],"predecessor-version":[{"id":216,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/posts\/82\/revisions\/216"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=\/wp\/v2\/media\/178"}],"wp:attachment":[{"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=82"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=82"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resources.aspergerworks.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=82"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}