Multiple Sclerosis

The Gut's Role in Multiple Sclerosis

Multiple sclerosis is an autoimmune condition where the immune system attacks the protective coating around nerve fibres, and gut bacteria have been proposed as one environmental factor shaping who develops it. A large, carefully designed study has found real, specific bacterial differences tied to both disease risk and disease course. This matters because MS has no single known cause, and understanding another piece of the puzzle could eventually open up new treatment angles beyond the immune-suppressing drugs used today.

A large, careful study with a genuine signal

The International Multiple Sclerosis Microbiome Study compared the gut bacteria of 576 MS patients against their own healthy household members, 1,152 people in total. This is a genuinely careful design. Household members share diet, environment, and often genetics, which isolates the disease-specific signal more precisely than comparing strangers. The study found significantly higher levels of Akkermansia muciniphila and significantly lower levels of Faecalibacterium prausnitzii, a beneficial, butyrate-producing bacterium, in people with untreated MS.

Source: Gut microbiome of multiple sclerosis patients and paired household healthy controls reveal associations with disease risk and course

Confirmed in the animal model of MS, and reducing inflammation in a real trial

That association raises the next question: does the gut bacteria itself actually cause any of this, or just track alongside it? Researchers have long studied MS using a mouse model called experimental autoimmune encephalomyelitis, which mimics the disease's nerve damage. Studies in this model have found that disturbing the gut bacteria of mice directly changes their vulnerability to developing this MS-like condition, adding a genuinely causal layer of evidence beyond the human association study above.

Building on that, a randomised controlled trial gave 40 people with MS either the probiotic yeast Saccharomyces boulardii or a placebo for four months. The probiotic group showed a significant reduction in hs-CRP, a blood marker of inflammation, and a significant increase in total antioxidant capacity compared with placebo. Both groups showed a reduction in a separate oxidative stress marker, with no significant difference between them, an honest, partial result rather than a uniform win.

Source: The effect of probiotic supplementation on the clinical and para-clinical findings of multiple sclerosis

As with any probiotic, these effects depend on the bacteria being properly fed. A strain given to help manage MS-related inflammation still needs fibre and plant compounds to establish itself well enough to keep influencing inflammatory markers over months of use.

Separate trials show improvements in daily symptoms

Beyond inflammation markers, other trials have looked at how gut-focused treatment affects everyday life with MS. A 12-week randomised controlled trial found that probiotics improved disability scores and mental health measures in people with MS, including reduced depressive symptoms, anxiety, and stress. A separate feasibility trial compared prebiotics with probiotics directly. Both were well tolerated, with only minor side effects, and probiotics specifically improved bowel control after six weeks, a genuinely practical symptom improvement for many people living with MS, where bowel problems are common but rarely discussed.

What this means for you

Multiple sclerosis needs ongoing management by a neurologist, and disease-modifying medication remains essential for controlling relapses and progression. Given the genuine trial evidence above, a specific probiotic strain is a reasonable, low-risk addition to discuss with a doctor alongside standard treatment, particularly for inflammation, mood, or bowel symptoms. A varied, plant-rich diet supports the same gut bacteria this research ties to a calmer immune response. That's the same idea behind GutLab, everyday gut health starts with regularly feeding the microbiome a broad range of plant-rich ingredients.