Abstract: There are tens of thousands of microbiota in the intestine, and the balance of these microbiota is essential to maintain intestinal stability and body metabolism. Once the intestinal flora structure is disordered, a variety of metabolic diseases will follow. In recent years, the international scientific researches focus on the relationship between intestinal flora and metabolic diseases, especially type 2 diabetes mellitus (T2DM). And the probiotics, as a kind of active microorganism that regulate the micro-ecological balance of the host's gut, can change the intestinal flora and their metabolites, and thus improve the host energy metabolism and reduce low level chronic inflammation and oxidative stress. Therefore, its intake has gradually become an usual method of preventing and controlling T2DM. This review provides an overview of the effects of probiotics on host intestinal flora and the mechanisms of improving T2DM, as well as a theoretical reference for the clinical application of probiotics.

Key words:  type 2 diabetes mellitus, probiotics, intestinal flora, short chain fatty acids, bile acids