Summary: New research reveals that when gut bacteria closely resemble the myelin sheath that protects nerve fibers, the immune system can become confused and attack both \u2014 accelerating multiple sclerosis. In mouse experiments, bacteria engineered to mimic myelin triggered faster disease progression by activating aggressive immune cells that infiltrated the nervous system.<\/p>\n
Remarkably, non-inflammatory bacteria carrying the same myelin-like features produced the opposite effect, slowing disease progression and hinting at the possibility of microbiome-based immune training. These findings highlight both the therapeutic promise and potential risks of manipulating gut microbes in autoimmune conditions.<\/p>\n
Key Facts:<\/p>\n
Molecular Mimicry: Gut bacteria with surface structures resembling myelin can trigger immune attacks on the nervous system.Disease Acceleration: Myelin-like inflammatory bacteria sped up MS progression in mouse models, while non-inflammatory versions slowed it.Therapeutic Potential: Modified bacteria may one day train immune cells to tolerate myelin, offering new microbiome-based treatment strategies.<\/p>\n
Source: University of Basel<\/p>\n
If gut bacteria are too similar to the protective layer of nerves, they can misdirect the immune system and cause it to attack its own nervous system. This mechanism can accelerate the progression of multiple sclerosis, as researchers at the University of Basel have shown in trials with mice. However, their results also open up opportunities for treatments that make use of the microbiome.<\/p>\n
When the immune system confuses friend and foe, autoimmune diseases develop. In the case of multiple sclerosis (MS), it mistakenly attacks the body\u2019s protective layer of nerve fibers, known as the myelin sheath. Those affected can experience exhaustion and numbness in their limbs, develop walking problems and may even become paralyzed.<\/p>\n
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The study shows that not only the composition of the intestinal flora plays a role in MS, but that specific myelin-like surface structures on certain bacteria could contribute to the initiation and progression of the disease. Credit: Neuroscience News<\/p>\n
Researchers have spent decades investigating the question of how this fatal error in our defenses occurs. More recent hypotheses also focus on the intestinal flora. This is because people with MS have a different composition of microorganisms in their intestines than healthy people.<\/p>\n
\u201cWe know that the intestinal flora influences the immune system, but the mechanisms related to MS are not fully understood,\u201d says Professor Anne-Katrin Pr\u00f6bstel from the Universities of Basel and Bonn. With her research group at the University of Basel and at the University Hospital Bonn, the neurologist investigates the role of the microbiome in neuroinflammatory diseases.<\/p>\n
Dangerous look-alikes<\/p>\n
One hypothesis suggests that pro-inflammatory gut bacteria, which have similar surface structures to the myelin sheath of the nerves, upset the immune system. The immune cells then attack both the harmful bacteria and the body\u2019s own myelin sheath. Experts refer to this likeness between bacteria and myelin sheath as \u201cmolecular mimicry\u201d.<\/p>\n
In a study published in the journal\u00a0Gut Microbes, Pr\u00f6bstel\u2019s research team, with lead authors Dr. Lena Siewert and Dr. Kristina Berve, has provided new evidence for this hypothesis.<\/p>\n
Using molecular biological methods, they modified pro-inflammatory\u00a0Salmonella\u00a0bacteria so that they had a surface structure similar to that of the myelin sheath. They used bacteria of the same species without a self-structure as controls.<\/p>\n
In genetically modified mice, which can serve as a disease model for MS, the myelin-like\u00a0Salmonella\u00a0bacteria caused a markedly faster progression of the disease than the control bacteria.<\/p>\n
\u201cThe pro-inflammatory bacteria alone only fuel the disease to a limited extent,\u201d explains Anne-Katrin Pr\u00f6bstel.<\/p>\n
\u201cBut the combination of an inflammatory environment and molecular mimicry activates specific immune cells. These multiply, migrate into the nervous system and attack the myelin sheath there.\u201d<\/p>\n
Training the immune system to tolerate rather than attack<\/p>\n
The research team conducted the same trials with\u00a0E. coli\u00a0bacteria, which are part of the normal intestinal flora and are non-inflammatory. When they implanted the myelin-like\u00a0E. coli\u00a0bacteria into the mice, the progression of the disease was milder.<\/p>\n
\u201cIn the future, if we work with different bacteria that actively calm the immune system instead of triggering it, we might be able to train immune cells to tolerate the myelin sheath and not attack it,\u201d says Pr\u00f6bstel.<\/p>\n
The study shows that not only the composition of the intestinal flora plays a role in MS, but that specific myelin-like surface structures on certain bacteria could contribute to the initiation and progression of the disease.<\/p>\n
It also provides valuable insights into the potential of microbiome-based treatments in MS. These could train the immune system with the help of specifically modified bacteria so that it no longer targets the myelin sheath.<\/p>\n
However, the results also call for caution: \u201cSome cancer treatments use the microbiome to stimulate the immune system to combat the tumor,\u201d says Anne-Katrin Pr\u00f6bstel. \u201cHowever, this may also create an environment in the intestine in which molecular mimicry can trigger autoimmune reactions or even diseases.\u201d<\/p>\n
The study was conducted in collaboration with the University Hospital Bonn, the Cluster of Excellence ImmunoSensation2\u00a0at the University of Bonn, the German Center for Neurodegenerative Diseases (DZNE), and other partner institutions.<\/p>\n
Funding: The study received financing from the University Hospital Basel\u2019s Propatient Foundation, the Swiss National Science Foundation and the State Secretariat for Education, Research and Innovation (SERI), among others.<\/p>\n
Key Questions Answered:Q: How can gut bacteria influence the progression of multiple sclerosis?<\/p>\n
A: The study shows that certain gut bacteria can carry surface structures that closely resemble the myelin sheath. When the immune system reacts to these bacteria, it may mistakenly attack myelin as well, accelerating MS progression through a mechanism known as molecular mimicry.<\/p>\n
Q: Why did myelin-mimicking bacteria worsen MS symptoms in the mouse model?<\/p>\n
A: In mice exposed to pro-inflammatory bacteria engineered to look like myelin, the immune system activated specific T cells that then migrated into the nervous system. This led to faster and more aggressive attacks on the myelin sheath compared to control bacteria.<\/p>\n
Q: Could the microbiome eventually be used to treat or prevent MS?<\/p>\n
A: Yes. The study suggests that using non-inflammatory bacteria engineered to resemble myelin might train the immune system to tolerate the myelin sheath rather than attack it. This opens the door to microbiome-based therapies designed to reduce autoimmune activity.<\/p>\n
Editorial Notes:This article was edited by a Neuroscience News editor.Journal paper reviewed in full.Additional context added by our staff.About this microbiome and multiple sclerosis research news<\/p>\n
Author: Angelika Jacobs<\/a> Original Research: The findings will appear in Gut Microbes<\/p>\n","protected":false},"excerpt":{"rendered":"Summary: New research reveals that when gut bacteria closely resemble the myelin sheath that protects nerve fibers, the…\n","protected":false},"author":2,"featured_media":351939,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[1334,33184,69345,97,686,14377,33186,5004,2471,1337,79,175182],"class_list":["post-351938","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-brain-research","tag-gut-bacteria","tag-gut-brain-axis","tag-health","tag-medicine","tag-microbiome","tag-microbiota","tag-multiple-sclerosis","tag-neurology","tag-neuroscience","tag-science","tag-university-of-basel"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/351938","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=351938"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/351938\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/351939"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=351938"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=351938"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=351938"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Source: University of Basel<\/a>
Contact: Angelika Jacobs \u2013 University of Basel
Image: The image is credited to Neuroscience News<\/p>\n