Intestinal IgA, which is regulated by gut microbiota, has a crucial role in maintenance of
intestinal homeostasis and in protecting the intestines from inflammation. However, the
means by which microbiota promotes intestinal IgA responses remain unclear. Emerging
evidence suggests that the host can sense gut bacterial metabolites in addition to pathogen-
associated molecular patterns and that recognition of these small molecules influences host
immune response in the intestines and beyond. We reported here that microbiota metabolite …