Abstract

Associations of intestinal dysbiosis and T cell dysfunctions in patients with collagen related diseases, such as Behcet's disease and relapsing polychondritis

Author(s): Jun Shimizu & Noboru Suzuki

Much attention has been focused on the relationships between gut microbiota and innate/adaptive immune systems in human diseases. We investigated bacterial composition and gene functions of the gut microbiota in two human immune disorders, "Behcet's Disease (BD)" and "Relapsing Polychondritis (RP)", with a metagenomic analysis by using a next generation sequencer. We found that distinctive features of gut microbiota existed in patients with BD, patients with RP, and normal individuals, suggesting a potential impact of the microbes to the intestine, as so called "dysbiosis" (unfavorable change of gut microbiota). We observed skewed T cell differentiation in both of the human diseases and speculated that there was a causal relationship between gut microbiota and T cells. To date, it was thought that some of the most important factors of T cell differentiation in the intestine were Short-Chain Fatty Acids (SCFAs). Several gut microbes provide SCFAs to the intestinal epithelial cells by the fermentation of dietary fibers. It is possible that characteristic and distinctive gut microbes lead to similar T cell dysfunctions in the intestine, contributing to development of both BD and RP.