Exposure to a social stressor alters the structure of the intestinal microbiota: Implications for stressor-induced immunomodulation

► Exposure to the social stressor, called social disruption, significantly changed the community structure of the intestinal microbiota. ► Stressor-induced increases in circulating IL-6 and MCP-1 were significantly correlated with stressor-induced changes in three members of the microbiota, Dorea spp., Coprococcus spp., and Pseudobutyrivibrio spp. ► Administration of a broad spectrum antibiotic cocktail to reduce the microbiota prevented the stressor-induced increase in IL-6 and splenic inducible nitric oxide synthase gene expression.