Trending this week in the world of the biome are two new papers[i] that definitively show that not only does multiple sclerosis starts in the gut but also, how the gut bacteria make the immune system turn against brain nerve cells.
The first paper, out of the University of California, San Francisco, showed that two particular bacterial groups, Acinetobacter and Akkermansia, were four times more abundant in MS patients than in normal controls. Also, another group of bacteria, Parabacteroides, was four times higher in healthy controls than in those with MS.
The researchers took naive immune cells (which turn into different types of immune cells depending on what they encounter) from those without MS and exposed them to the bacteria found in the guts of the MS patients, and these cells “…became a particular type of T helper cell, which trigger inflammation and help the immune system kill off invaders or infected cells…” Amazingly too, Acinetobacter also “…ramped down the production of regulatory T cells, which help prevent autoimmune diseases by dampening the immune response.”
When the researchers transferred the bacteria from the MS patients into germ-free mice, they induced severe brain inflammation within 20 days.
The 2nd amazing paper was just published in the Proceedings of the National Academy of Sciences. They looked at 34 sets of identical twins, only one of whom had MS, and found that Akkermansia was significantly more abundant in those with MS than in their healthy twins. These researchers then transferred the gut microbes from the twins into mice and found that after 12 weeks, “…three times as many mice receiving bacteria from MS patients developed brain inflammation as those receiving microbes from healthy donors.” And again, incredibly importantly, “Gut bacteria from MS patients also seemed to block the production of molecules, like the cytokine IL-10, that reduce inflammation.” (IL-10 is one of the most important components of the regulatory system.)
Really amazing stuff, this.