Abstract

A vast number of micro-organisms within the human gut play a crucial role in maintaining human health. Intestinal microbiota maintains the intestinal homeostasis and function by mutually interacting with the host's epithelial cells and mucosal immune system; and the immune tolerance towards intestinal commensals should be permitted for such interactions to occur. In recent years, the prevalence of inflammatory bowel diseases has greatly increased, and the pathogenic pathway behind is considered to be related to an aggressive immune response which is a subset of commensal enteric bacteria in a genetically susceptible host. The abnormal host-microbial interactions play an important role in the pathophysiology of inflammatory bowel diseases, which have been proved through numerous studies in the field of genetics, molecular microbiology, immunology, and experimental rodent models, as well as various translational researches and clinical trials. This review briefly summarizes the composition and function of intestinal microbiota, interactions between the microbiota and the immune system, and the possible roles of the intestinal microbiota in the pathogenesis of inflammatory bowel diseases. (Intest Res 2013;11:161-168)

• Keywords: Microbiota; Inflammatory bowel diseases; Host-pathogen interaction