Social stress-responsive microbiota

Stressful life events are considered a risk factor for autoimmune disorders, though the mechanisms are unclear. Here we demonstrate that chronic social stress induced virulence- associated transcriptional patterns in the murine gut microbiota. The stress-influenced microbiota increased the presence of effector-T-helper cells in the mesenteric lymph nodes, including myelin-auto-reactive cells. Inhibition of the bacterial quorum-sensor QseC, which is also responsive to norepinephrine, diminished the presence of effector-T-helper cells and bacteria such as Acinetobacter in the mesenteric lymph nodes, without remarkably affecting the gut microbial composition. Together our results delineate a model in which the immune reaction to stress-responsive microbiota may compromise tolerance to self, and therefore may increase the risk for autoimmune diseases in susceptible individuals.