大豆异黄酮对2型糖尿病小鼠脂代谢及肠道菌群结构的影响

IMPROVEMENT OF LIPID METABOLISM AND INTESTINAL FLORA STRUCTURE BY SOYBEAN ISOFLAVONES IN TYPE 2 DIABETIC MICE

目的利用2型糖尿病小鼠模型,评估不同剂量大豆异黄酮对T2DM小鼠生理生化、血液指标、及肠道菌群的影响。方法建造2型糖尿病小鼠模型,成功后,随机分为2型糖尿病模型对照组(type 2 diabetes model control group,T2DM)、二甲双胍阳性对照组(metformin positive control group,PC)、大豆异黄酮不同剂量干预组(75、150、300mg/kg)(soybean isoflavones 75、150、300 mg/kg,SI75、SI150、SI300)。每周监测饮水量、摄食量、空腹血糖(fasting blood glucose,FBG)及体重(body weight,BW)。灌胃6w后,测定小鼠血清甘油三酯(triglycerides,TG)、胆固醇(cholesterol,CHO)、高密度脂蛋白胆固醇(high-density lipoprotein-cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol-cholesterol,LDL-C)、白介素-1β(interleukin-1β,IL-1β)含量。HE染色观察肝、肾病理学变化。采用高通量测序技术分析空肠菌群结构变化。结果大豆异黄酮干预使小鼠体重呈现整体增加趋势,且高剂量组上升态势较低剂量组明显(P<0.05);大豆异黄酮高剂量干预能显著降低T2DM模型小鼠的血清TG(P<0.01)、CHO(P<0.01)、LDL-C(P<0.01)和IL-1β(P<0.01)的水平;相比T2DM组,大豆异黄酮干预组的肝重和肾重指数均有所降低;对各组小鼠肠道菌群结构分析,相比正常对照组(normal control group,NC),在其他各组中乳酸菌属比例升高;Allobaculum在其他各组中含量极低;苏黎世杆菌属在T2DM组、SI75组几乎消失,但在SI150、SI300中比例升高;Faecalibaculum比例降低;相比NC组,T2DM组的拟杆菌属S24-7群-norank相对增加,而大豆异黄酮干预后明显降低。对各组小鼠空肠菌群结构进行PCA分析,NC组、T2DM组、SI干预组有明显不同的聚类,但SI各组之间聚类差异不明显。结论大豆异黄酮高剂量干预6w可以有效降低T2DM模型小鼠的空腹血糖、TG、LDL-C、炎症因子—IL-1β水平,改善T2DM小鼠"多食"和"多饮"症状,相对增加体重,并可能通过减少炎症的发生从而对肝、肾产生保护作用;大豆异黄酮也可升高T2DM小鼠乳酸菌属比例,降低拟杆菌属S24-7群-norank,降低Allobaculum。

Objective To evaluate the effects of soybean isoflavones on lipid metabolism,and intestinal flora in type 2 diabetes(T2DM mice).Methods After successful development of T2DM mice were randomly divided into model control group(T2 DM),metformin positive control group(PC),and soybean isoflavones intervention groups(soybean isoflavones 75,150,300 mg/kg,SI75,SI150,SI300).Food intake and water intake were measured once a week.Body weight and fasting blood glucose(FBG)were measured every week.After intragastric administration of soybean isoflavones for 6 weeks,serum triglycerides(TG),cholesterol(CHO),high-density lipoprotein-cholesterol(HDL-C),and low-density lipoprotein-cholesterol(LDL-C),interleukin-1β(interleukin-1β,IL-1β)were examined.HE staining was used to observe pathological changes of the liver,kidney and pancreas.High-throughput sequencing technology was used to analyze the structural of the jejunal flora.Results The intervention of soybean isoflavones showed an overall increase in body weight,and the increase in the high-dose group was statistically significant higher than in the lower-dose group(P<0.05).High-dose intervention of soybean isoflavones could significantly reduce serum triglycerides cholesterol(P<0.01),LDL-C(P<0.01)and IL-1β(P<0.01)levels in T2DM mice(P<0.01).Compared with the T2DM group,the soybean isoflavone intervention group had smaller liver weight and kidney weight indexes.Compared with the normal control group(NC),the proportion of lactic acid bacteria were higher in the other groups;the abundance of Allobaculum in the other groups was extremely low.The Zurich bacterium in the T2DM group and SI75 group almost disappeared,but the proportion of SI150 and SI300 increased,and the proportion of Faecalibaculum decreased.Compared with the NC group,the Bacteroides S24-7 group-norank of the T2DM group increased relatively,and reduced after the soy isoflavone intervention.PCA analysis of the structure of the jejunal flora found that the NC group,T2DM group,and SI intervention groups had significantly different clusters,but the clustering difference between different SI groups was not obvious.Conclusion High-dose soybean isoflavone intervention for6 weeks can effectively reduce the levels of fasting blood glucose,TG,LDL-C,and inflammatory factor-IL-1βin T2DM mice,and improve the symptoms of"polyphagia"and"polydipsia".It may also protect the liver and kidneys by reducing inflammation.Soy isoflavones can also increase the proportion of Lactobacillus,reduce Bacteroides S24-7 group-norank and Allobaculum in T2DM mice.