Abstract: Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease that mainly affects the rectum, colonic mucosa and submucosa. UC has recently attracted growing research interest because of its increased incidence. With the development of 16S rDNA sequencing technology and metabolomics, intestinal flora structure and metabolites have been found to be closely related to the occurrence and development of UC. As a group of intestinal beneficial bacteria, probiotics have the functions of enhancing intestinal barrier, regulating intestinal immunity and maintaining intestinal balance, and play a significant role in the treatment of UC. This article reviews the mechanism of action of intestinal flora on ulcerative colitis and recent progress in understanding the effect of probiotics on UC.

Key words: ulcerative colitis, gut microbiota, probiotics