Abstract: Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory condition. Although the etiology of IBD is unknown， the dominant hypothesis suggests the inflammation results from sustained immune response towards altered microbiota within a genetically susceptible host. Gut microbiota plays a significant role in  pathogenesis of IBD. In this article， we describe a healthy microbiota，review the important microbiome studies of IBD and talk about the related therapy， such as probiotics and fecal microbiota transplantation.

Key words: inflammatory bowel diseases, gut microbiota, probiotics; , transplantation