[https://www.technologynetworks.com/neuroscience/news/gut-immune-cells-are-recruited-to-fight-multiple-sclerosis-313487]
__Gut microbes trigger blood ((Circulatory - Lymphatic System|plasma cells)) to counteract inflammation in the brain, that lead to ((Nervous - Myelin Sheath|demyelination)):__

"Researchers at the University of Toronto and UC San Francisco have discovered that the intestine is the source of immune cells that reduce brain inflammation in people with multiple sclerosis (MS), and that increasing the number of these cells blocks inflammation entirely in a preclinical model of the disease.

The cells in question are plasma cells — white ((Circulatory - Blood|blood))  cells that originate as B cells in the ((Musculoskeletal - Bones|bone)) marrow but change their behavior when triggered by microbes in the gut. Studying mice and samples from human MS patients, __the researchers found that plasma cells that reside in the gut and produce Immunoglobulin A (IgA) antibodies appear to migrate to the central nervous system and produce an anti-inflammatory effect during MS flare-ups__.
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A key next step for the researchers is to figure out what microbes in the gut promote the generation of immunosuppressive IgA plasma cells. “If we can understand what these cells are reacting to, we can potentially treat MS by modulating our gut commensals,” said Gommerman, referring to the bacteria that live in the healthy gut. “That might be easier than getting drugs into the brain, which is a strategy that hasn’t always worked in MS.”

The study also raises questions about the microbiome and lifestyle choices. Do certain lifestyles nudge some people toward a gut microbiome that allows immunosuppressive plasma cells to flourish? Are specific foods conducive to creating that environment and if so, might a drug or supplement mimic the effect? Genetics are just one factor that affect susceptibility to MS; the current study highlights how non-genetic factors may confer disease resistance."