植物乳杆菌对2型糖尿病大鼠的影响及影响机制

On the Effect of Lactobacillus plantarum on Type 2 Diabetic Rats and Its Mechanism

探究植物乳杆菌对2型糖尿病大鼠的影响及影响机制。对雄性SD大鼠采用高脂饮食和腹腔注射链脲佐菌素(STZ)的方法诱导其建立2型糖尿病动物模型,将建模成功的大鼠随机分为糖尿病组、高剂量干预组(1.016×10^(8)CFU/100 g·BW)和低剂量干预组(2.4×10^(7)CFU/100 g·BW),将由普通饲料喂养的大鼠作为对照组。干预过程中对大鼠的体重、空腹血糖(FBG)、餐后两小时血糖(2hPBG)以及糖耐量等数据进行测定。第15周后检测血脂和血清胰岛素(INS)水平,评估胰岛素抵抗指数(HOMA-IR),对大鼠粪便进行高通量测序,利用Western Blot方法测定糖脂代谢通路及胰岛素信号传导通路中相关蛋白的表达。植物乳杆菌显著提高了糖尿病大鼠体内的糖耐量、胰岛素耐量水平和HOMA-IR,改善了血脂水平异常的情况;增加了大鼠肠道菌群的多样性及丰富度,优化了大鼠肠道菌群的结构及组成,使有害菌减少,有益菌增多;显著上调PI3K、AKT蛋白表达;下调PCK1、GSK-3β蛋白表达;显著上调P-AMPK、P-ACC1蛋白表达,下调SREBP1蛋白表达,其中低剂量植物乳杆菌的干预效果更显著。适量的植物乳杆菌可以调节肠道菌群的组成及结构,激活糖脂代谢通路及胰岛素信号传导通路,改善2型糖尿病大鼠体内糖脂代谢紊乱和胰岛素信号传导异常的情况。

The objective of this study was to investigate the effect and mechanism of Lactobacillus plantarum on type 2 diabetic rats.Male SD rats were induced to establish animal models of type 2 diabetes by high-fat diet and intraperitoneal injection of streptozotocin(STZ).The rats were randomly divided into diabetic group and high-dose bacteriocin intervention group(1.016×10^(8) CFU/100 g·BW)and low-dose bacterial agent intervention group(2.4×10^(7) CFU/100 g·BW);rats fed with ordinary diet were used as the control group.Body weight,fasting blood glucose(FBG),two-hour postprandial blood glucose(2 hPBG)and tolerance were measured during the intervention.After the 15th week,the levels of blood lipid and serum insulin(INS)were detected;the insulin resistance index(HOMA-IR)was evaluated;the feces of rats were sequenced with high-throughput,and the expression of related proteins in glucose and lipid metabolism pathway and insulin signal transduction pathway were measured by Western blot.Lactobacillus plantarum significantly increased glucose tolerance,insulin tolerance and HOMA-IR in diabetic rats,and improved lipid levels;increased the diversity and richness of rat gut microbiota,improved the structure and composition of rat gut microbiota,reduced harmful bacteria,and increased beneficial bacteria;Significantly upregulated the expression of PI3K and AKT proteins;lowering PCK1 and GSK-3β Protein expression;Significantly up-regulated the expression of P-AMPK and P-ACC1 protein,down regulated the expression of SREBP1 protein,and the intervention effect of low-dose Lactobacillus plantarum was more significant.The appropriate dose of Lactobacillus plantarum can regulate the composition and structure of intestinal flora,activate the glucose and lipid metabolic pathway and insulin signaling pathway,and improve the glucose and lipid metabolism disorder and insulin signal conduction abnormalities in type 2 diabetic rats.