薯蓣粥对T2DM大鼠肠道微生物、血糖、胰岛素的影响

目的:探讨薯蓣粥对2型糖尿病（type 2 diabetes mellitus，T2DM）大鼠肠道微生物、短链脂肪酸（short-chain fatty acids，SCFAs）血糖、胰岛素分泌的影响。方法:将60只SPF级Wister大鼠随机抽取10只为空白组，剩余50只腹部注射链脲佐菌素（STZ）制作T2DM模型，成模后大鼠随机分为模型组、薯蓣粥组、二甲双胍组、联合组；空白组和模型组每日用生理盐水灌胃5 mL，薯蓣粥组每日用薯蓣粥灌胃5 mL，二甲双胍组每日用二甲双胍水溶液灌胃，联合组用薯蓣粥+二甲双胍灌胃，共干预6周；干预期间每周检测大鼠空腹血糖（FBG），干预后检测大鼠肠道菌群构成以及FBG、空腹胰岛素（FINS）水平、粪便内SCFAs的含量。结果:与空白组相比，模型组大鼠空腹血糖、空腹胰岛素含量、胰岛素抵抗指数均升高（P<0.05），粪便中乙酸、丙酸、丁酸含量，以及OTUs（Operational Taxonomic Units）、Chao1指数、Shannon指数明显降低（P<0.05），厚壁菌门、疣微菌门、颤螺菌、阿克曼氏菌、梭菌的相对丰度降低（P<0.05），变形菌门相对丰度增加（P<0.05）。干预4周，薯蓣粥组大鼠空腹血糖出现明显降低（P<0.05）。干预结束后薯蓣粥组大鼠的空腹血糖、空腹胰岛素含量、胰岛素抵抗指数均低于模型组（P<0.01），空腹胰岛素含量、胰岛素抵抗指数与二甲双胍组、联合组相比没有统计学差异（P>0.05）。薯蓣粥组与模型组相比，粪便中乙酸、丙酸、丁酸的含量均升高（P<0.01）；OTUs指数升高，厚壁菌门、疣微菌门、阿克曼氏菌、梭菌的相对丰度升高，变形菌门的相对丰度降低（P<0.05）。结论:薯蓣粥可能通过改善T2DM大鼠肠道微生物失调，增加SCFAs含量，从而改善胰岛素抵抗，降低血糖。

Effects of Yam Gruel on Gut Microflora,Blood Glucose and Insulin in T2DM Rats

Objective: To investigate the effect of yam gruel on gut microflora, short chain fatty acids (SCFAs), blood glucose and insulin secretion in type 2 diabetic rats. Methods: 60 SPF Wister rats were randomly selected as blank group, and the remaining 50 rats were injected with streptozotocin (STZ) to make T2DM model. The rats were randomly divided into model group, yam gruel group, metformin group and combination group. The blank group and model group were given 5 mL normal saline, the yam gruel group was given 5 mL yam gruel every day, the metformin group was given metformin aqueous solution every day, and the combination group was given yam gruel and metformin for six weeks. The fasting blood glucose (FBG) of rats was detected every week. After the intervention, the blood glucose, fasting insulin (FINS), gut microflora composition and the content of SCFAs in feces were detected. Results: Compared with the blank group, the FBG, FINS and insulin resistance index of the model group were increased (P<0.05), the contents of acetic acid, propionic acid, butyric acid, OTUs, Chao1 index and Shannon index were significantly decreased (P<0.05), the relative abundance of Firmicutes, Verrucomicrobia, Oscellospira, Akkermansia and Clostridium decreased (P<0.05), and the relative abundance of Proteobacteria increased (P<0.05). After 4 weeks of intervention, blood glucose of rats in Yam gruel group decreased significantly (P<0.05). The FBG, FINS and HOMA-IR of the yam gruel group were significantly lower than those of model group (P<0.05). The FINS and HOMA-IR of the yam gruel group were no significant difference between metformin group, combination group. Compared with the model group, the contents of acetic acid, propionic acid and butyric acid of the yam gruel group increased (P<0.01), the OTUs, Firmicutes, Verrucomicrobia, Akkermansia and Clostridium of the yam gruel group increased, and Proteobacteria of the yam gruel group decreased (P<0.05). Conclusion: Yam gruel might improve insulin resistance and reduce blood glucose by improving intestinal microbial imbalance and increasing SCFAs content in T2DM rats.