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Two teams of scientists have found the strongest evidence yet that intestinal bacteria play a role in multiple sclerosis, an incurable disease in which the body’s immune system attacks the myelin coating on neurons, causing tremors, fatigue, cognitive problems, and more.

Gut germs that were unusually abundant in people with MS changed white blood cells in a way that made them more likely to attack the body’s own cells, including neurons, one study reported on Monday; the other experiment found that gut germs from people with MS made mice more likely to develop the disease than did gut germs from their identical but healthy twins.


You’ll want to know:

Although it might seem crazy that gut bacteria could affect neurons, evidence for that has been steadily accumulating, so much so that an international consortium is devoted to understanding which microbes protect against or promote MS.

The new studies strengthen the case for an MS-microbiome link.

In one, scientists led by Sergio Baranzini of the University of California, San Francisco, analyzed the microbiomes of 71 MS patients and 71 healthy people. Bacteria called Acinetobacter and Akkermansia were very rare in healthy people but more abundant in the MS patients.


That was in line with earlier studies finding, for instance, that people with one form of MS have different gut bacteria than healthy people. But the earlier work didn’t show whether having MS changes the gut microbiome or vice versa. The UCSF team therefore took the next step, running what Baranzini called “the most stringent test of causality.”

They put Acinetobacter and Akkermansia bacteria into samples of healthy blood. The microbes increased the kind of cells that activate immune attack (they’re called T helper cells) and decreased the kind (regulatory T cells) that suppress excessive immune responses, including autoimmune attacks as in MS.

There was another intriguing connection: at least one species of Acinetobacter has molecules on its surface that mimic myelin, the nerve cell coating that the immune system attacks in MS. That suggests the bacteria might trigger immune attacks that hit myelin, too, as when soldiers who inadvertently resemble the enemy get hit by friendly fire. The discoveries, the UCSF team wrote in Proceedings of the National Academy of Sciences, suggest “a previously unknown environmental contributor to MS.”

In the second study, scientists led by Hartmut Wekerle of Germany’s Max Planck Institute of Neurobiology examined 34 pairs of twins in which only one of each had MS. Transplanting gut microbes from the twins into lab mice that develop MS, they found that more of the mice receiving the MS microbiome developed a mouse version of MS than did mice receiving transplants from the healthy twin.

Why it matters:

If the results are right, and if certain gut bacteria are necessary for MS, they could serve as the basis for microbiome-based therapy or even prevention of the disease. Much as fecal transplants from healthy donors treat life-threatening infections of the bacterium C. difficile, so they might be used to treat MS — or, if given before someone with a genetic risk develops MS, prevent it.

Alternatively, probiotics that preferentially nourish bacteria that compete with the MS-causing kinds might keep the latter in check, Baranzini said, though he cautioned that probiotics have not yet been shown to cause the wholesale microbiome changes that might be needed to prevent or cure disease.

What they’re saying:

Scientists not involved in the new studies used phrases such as “unique insights” and “major advance” to describe the results. Together, the experiments show that bacteria in the guts of people with MS promote disease-causing immune activity, said immunologist Francisco Quintana, of the Ann Romney Center for Neurologic Diseases at Brigham and Women’s Hospital in Boston, who said these were “landmark papers.” Ashutosh Mangalam, of the University of Iowa Carver College of Medicine, who led a 2016 study finding that people with MS have a microbiome different from healthy people’s, was more cautious, however. Because both of the new studies transplanted the entire community of gut bacteria from people into mice, they couldn’t show which particular bugs played necessary or sufficient roles in MS.

But keep in mind:

The explosion of microbiome research has led to inflated claims. It’s too soon to know how important the microbiome is in increasing the risk of MS compared to the 200 genetic variants that have been linked to the disease, or compared to the Epstein-Barr virus, smoking, and low levels of vitamin D, which also seem to play a role. Even the new studies clashed somewhat: Unlike the UCSF study, the German research found no major differences between the overall microbiomes of twins with and without MS. Finally, mouse models of MS are not perfect analogues of the human disease, and mouse immune systems aren’t identical to people’s.

The bottom line:

Together, the two studies advance the idea that gut microbes play a role in turning the immune system against nerve cells, causing MS. It will take a lot more work to develop cures or preventive strategies based on that, but the research raises the intriguing possibility of treating an often-devastating disease with something as low-tech as fecal transplants or probiotics.

  • We have seen a common pattern with microbes, leading to inflammation and finally some sort of chronic disease. In each case, the offending bacteria may not necessarily be “bad”, but more so “in the wrong neighborhood”. What we keep seeing is a phenomenon of gram-negative bacteria “snuggling up to” the epithelium and the LPS initiating an inflammatory response. Depending on the location and organism, different diseases emerge. In most cases, there is a mucosal barrier function issue. In the colon we find that insufficient soluble fiber feeding bacteria that produce butyrate may be at the root. In the upper GI it is insufficient fiber feeding the bacteria that fend off a type of gram-negative “infection” at the LES. Hence, the title of the article should have been “Gut germs play role in multiple sclerosis, studies show. Are [prebiotics/fiber/microFood] for MS next?” since this appears to be about microbial malnutrition and not about insufficient microbial populations.

  • Hello my name ia Larry and I have MS. I would like to communicate more about therapy for MS… In perticular I am interested in which bacteria may be helpful in curing MS… Thanks for your interesting work!

  • Search harder, including international research literature. I personally have met a half dozen people who recovered from clinical diagnoses of MS through removing amalgam safely working with biologic dentists who have special equipment and controls. Their testimony (along with dentists, physicians and researchers) is on the record at FDA hearings, which were quickly archived so not easy to find. If it was not MS, their specialists and specialty clinics were wrong. What matters most is that they recovered their health. Mercury is not the only trigger, but it is for some. Safe removal will not work for everyone, but it helps for some. Unsafe removal will increase exposure and make it worse for those with genetic susceptibilities.

    The myth you are referring regarding amalgam safety is propagated by the ADA. It was founded to promote amalgam nearly 160 years ago, its affiliates have held patents on it (the AMA holds no patents to avoid conflicts), has gag orders in its code of ethics on it, and spends millions each year on campaign contributions, lobbying, PR, legal, sponsored research, and advertising to keep the myth alive in the United States.

    You might be interested to learn that the FDA twice overruled a majority of its own expert dental products panels by declining to require disclosure to patients of health risks of dental amalgam for vulnerable subpopulations. You might be interested to learn that a growing number of other nations ban, restrict, or are working to phase down use of dental amalgam consistent with the International Minamata Treaty on Mercury.

  • For some MS patients, such as Nashville FoxNews reporter Stacy Case, recovery can be as low-tech as safe dental amalgam removal by a biologic dentist and reducing the body burden of neurotoxic mercury, which harms the gut lining, nervous system, brain, kidneys and more. MS has multiple triggers, and mercury is one of them for people with weaker methylation pathways due to genetic factors. Our nation’s health and healthcare costs would benefit if we focused as much attention on triggers as treatments.

    • This response is to Bethany. Thank you for mentioning my miraculous recovery & eventually me being undiagnosed of MS. Facts are important. I have never taken any MS pharmaceutical treatments. The dr wouldn’t give me any because I kept getting better instead of worse as I continued down the path to restored health through safe removal of my mercury fillings using the IAOMT specific protocol for safe removal, followed by IV chelation of DMPS & EDTA alternating with IV minerals and vitamins, an anti inflammatory diet, hyperbaric O2 treatment to repair nerve connections & multiple oral supplements and oral vitamins to help rebuild my CNS from the inside out. The studies are well documented on mercury and its effect on the central nervous system. There’s simply no debate to be had. Thank you for sharing your thoughts… though yours are all inaccurate as they relate to me personally. Again, facts are important. Be Vigilant, Be Well

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