Autoimmune Flare-Ups in Multiple Sclerosis May Be Influenced by Dietary Fat

Results from a recent study published in the journal Immunity indicate that dietary fat has an influence in the duration and severity of autoimmune flare-ups in a mouse model of multiple sclerosis. The team of researchers also showed that adjusting the length of the fatty acids consumed by mice caused an alteration in the function of gut T helper cells — either increasing or lessening the multiple sclerosis symptoms.

Growing empirical evidence suggests that nutrition and bacterial metabolites might impact the systemic immune response in the context of disease and autoimmunity. In the study entitled “Dietary Fatty Acids Directly Impact Central Nervous System Autoimmunity via the Small Intestine,” Dr. Ralf Linker, of Friedrich-Alexander-University Erlangen-Nuremberg, and his colleague, Aiden Haghikia, from the Ruhr-University Bochum, both in Germany, conducted a comparative analysis in mice assessing the effects of short-chain fatty acids and long-chain fatty acids.

Results revealed that the long-chain fatty acids stimulated the development and release of proinflammatory T cells from the intestinal wall to other areas in the body, such as the brain, which led to a more severe disease in the animals. Short-chain fatty acids, in contrast, stimulated the development and propagation of regulatory T cells that kept the immune response in check, which was found to ameliorate the disease in mice.

None of the effects of dietary fatty acids were observed in mice who had their intestines germ-free, implying that gut bacteria are involved in this mechanism.

In sum, the results showed that:

• Dietary fatty acids have profound influence on T cell differentiation in the gut
• Middle- and long-chain fatty acids support Th1 and Th17 cell differentiation
• Short-chain fatty acids lead to increased Treg (regulatory T cell) differentiation
• Long-chain fatty acids worsen disease in a multiple sclerosis animal model; short-chain fatty acids exert the opposite effect.

“Most approved immunotherapies weaken or block proinflammatory components of the immune system, but by strengthening regulatory pathways, for example by using propionate [a short-chain fatty acid] as a supplement to established drugs, therapies could be further optimized,” noted Dr. Linker in a recent news release.

“It is now our plan to employ our gained insights to develop innovative dietary add-on therapies to established immunotherapies in multiple sclerosis,” added Dr. Haghikia, the study’s first author.

Concluded the research team, “These data demonstrate a direct dietary impact on intestinal-specific, and subsequently central nervous system-specific, Th cell responses in autoimmunity, and thus might have therapeutic implications for autoimmune diseases such as multiple sclerosis.”