Studies have consistently found people with MS to have markedly different gut microbiomes from those who don’t have the disease, although what this means for people living with MS isn’t fully understood. Here’s what researchers do know.

The relationship between the gut and MS is complex, according to J. William Lindsey, MD, director of the division of multiple sclerosis and neuroimmunology at the University of Texas Health Science Center at Houston. “It involves interactions between diet, nutritional status, the bacteria in the gut, and the activity of the immune system,” he explains. How does all this intertwine? For starters, “diet affects nutritional status, and it also changes the composition and activity of the bacteria in the gut microbiome,” says Dr. Lindsey. This disruption in the gut bacteria can set off a chain reaction. “The microbiome can affect the activity of the white blood cells in the intestine, and these white blood cells can migrate to other parts of the body, including the brain,” explains Lindsey. “The microbiome also produces metabolites such as short chain fatty acids and altered bile acids that get into the blood and affect immune system activity.” Because MS is an autoimmune disease of the central nervous system, these disruptions, which lead to an increase in pro-inflammatory bacteria in the gut, are thought to impact the condition.

Can Modifying Bacteria in the Gut Change the Course of MS?

Maintaining a consistently healthy diet can impact the gut microbiome. And findings from various small studies done both in people and in mice suggest a healthy diet can reduce MS disease activity, especially in combination with disease-modifying therapy and other healthy lifestyle habits. However, these aren’t definitive studies — more research consisting of larger studies is needed to help clarify the role diet plays in modifying the gut microbiome and managing MS.

MS-Friendly Diet Tips to Promote Gut Health

Regardless of what we know — and still don’t know — about the link between the gut microbiome and MS, research has shown that taking steps to eat a healthy diet is considered an important part of an overall MS management plan. “And a healthy diet can lead to a healthier microbiome,” adds Lindsey. That said, studies are limited by a focus on MS outcomes, and there aren’t many analyses specifically looking at microbiome composition in response to diet. While there are no dietary guidelines specific to MS, the same eating plans known to support cardiovascular health and promote healthy aging — such as the DASH and Mediterranean diets — are also good for MS, explains Lindsey. That means eating a diet focused on:

FruitsVegetablesWhole grainsLegumesNutsSeedsHealthy fats

And limiting:

Processed foodsAdded sugarsRefined grains

Can Probiotics Help?

The terms “gut health” and “probiotics” often go hand in hand. That’s because increasing your intake of probiotics, or “good” bacteria, can help reduce inflammation in your gut. Unmanaged inflammation is what triggers the overactive immune response. Studies have shown that consuming probiotics may help prevent MS to begin with. And for people who develop MS, probiotics may help reduce its severity, delay progression, and improve certain MS symptoms. Though larger, more comprehensive research is needed on this topic as well. Probiotics can be found in fermented foods such as:

KefirKimchiKombuchaMisoPicklesSauerkrautTempehYogurt

Probiotics also come in the form of supplements for people who don’t care for the signature sour, yeasty flavor of food sources. That said, only certain strains of Lactobacillus and Bifidobacterium have been proven to be beneficial for MS. It’s important to note probiotic supplements are not regulated by the U.S. Food and Drug Administration, so before you stock up, check with your doctor. Given the link between the gut microbiome and MS isn’t yet fully understood, it’s best to err on the side of caution. That said, it’s probably fine to dine on all the kimchi and yogurt you like.