目的:探究二甲双胍对2型糖尿病合并肥胖患者肠道细菌群落结构和功能的影响。方法:选取2型糖尿病合并肥胖患者30例，借助高通量测序手段比较二甲双胍治疗前后肠道菌群多样性、群落结构和功能的差异。结果:二甲双胍能够显著增加肠道菌群群落多样性和丰富度，调节肠道菌群群落结构，增强氨基酸代谢、碳水化合物代谢、脂质代谢、丙酸代谢和丁酸代谢等多种代谢功能，同时显著抑制2型糖尿病、胰岛素抵抗以及胰高血糖素信号通路等功能基因的表达。结论:二甲双胍可通过影响肠道菌群结构和功能参与降糖过程。“,”Objective:To explore the effect of metformin on intestinal bacterial community structure and function in obese patients with type 2 diabetes mellitus.Method:Thirty obese patients with type 2 diabetes mellitus were selected to compare the differences of intestinal flora diversity, community structure and function before and after metformin treatment by means of high-throughput sequencing.Result:Metformin could significantly increase the diversity and richness of intestinal flora community, regulate the structure of intestinal flora community, enhance a variety of metabolism functions such as amino acid metabolism, carbohydrate metabolism, lipid metabolism, propanoic acid metabolism and butanoate metabolism, and significantly inhibit the expression of functional genes such as type 2 diabetes mellitus, insulin resistance and glucagon signaling pathway.Conclusion:Metformin can participate in the hypoglycemic process by affecting the structure and function of intestinal flora.