The Meta Analysis Of The Relationship Between High Fat Diet And The Changes Of Intestinal Microecology In Mice And Rats

Objective A Meta analysis was made to review systematically the relationship between high fat diet and the changes of intestinal microecology in mice/rats.Methods Databases included Pub Med,EMbase,the Cochrane Library,China Biology Medicine disc(CBM),China National Knowledge Infrastructure(CNKI),VIP database(VIP)and Wanfang database were searched from inception to January 2017 to collect the randomized controlled studies on the correlation between high fat diet and intestinal microecology.Languages were Chinese and English.The Meta analysis was performed using the Rev Man 5.3.The quality of the included literatures was evaluated by using a predetermined protocol,established according to the Cochrane Handbook's recommendations.Heterogeneity analysis was made by Q statistics and I2 test.The standardized mean difference(SMD)and its 95% confidence interval(CI)were used to analyze the continuous variables.Subgroup analysis was made to test for heterogeneity sources.Results All of the 15 studies were randomized controlled trials.The results of Meta analysis showed there were 8 studies about the change of intestinal bifidobacteria in mice/rats after high-fat diet.Subgroup analysis was performed according to the source of samples(fecal or cecal contents): the group of fecal sources:SMD:-4.45,95% CI:-7.63~-1.27,P=0.006,and the group of cecal contents:SMD:-3.51,95% CI:-6.03~-0.99,P=0.006,it showed that intestinal bifidobacteria decreased after high fat diet.There were 8 studies about the change of intestinal Bacteroides in mice/rats after high-fat diet,subgroup analysis was performed according to the different subjects(mice or rats):the group of mice:SMD:-0.5,95% CI:-1.73~0.72,P=0.42,the group of rats:SMD:-1.46,95% CI:-2.58~-0.35,P=0.01,it showed that intestinal Bacteroides decreased after high fat diet.There were 4 studies about the change of intestinal enterococci in mice/rats after high-fat diet,SMD:-3.99,95% CI:-11.08~3.10,P=0.27,it showed that intestinal enterococci decreased after high fat diet.There were 6 studies about the change of intestinal Enterobacteriaceae in mice/rats after high-fat diet,SMD:3.93,95% CI:0.53~7.32,P=0.02,it showed that intestinal Enterobacteriaceae decreased after high fat diet.There were 8 studies about the change of intestinal Lactobacillus in mice/rats after high-fat diet,subgroup analysis was performed according to different subjects:the group of mice:SMD:-3.26,95% CI:-5.86~-0.65,P=0.01,the group of rats:SMD:-6.53,95% CI:-11.55~-1.52,P=0.01,it showed that intestinal Lactobacillus decreased after high fat diet.There were 7 studies about the change of body weight in mice/rats after high-fat diet,SMD:3.74,95% CI :2.81~4.67,P<0.00001,the results showed that the weight of mice/rats increased after high-fat diet.There were 9 studies about the change of plasma total cholesterol in mice/rats after high-fat diet,subgroup analysis was performed according to different subjects:the group of mice:SMD:4.67,95% CI:3.05~6.29,P<0.00001,the group of rats:SMD:1.96,95% CI:1.27~2.66,P<0.00001,the results showed that the plasma total cholesterol of mice/rats increased after high-fat diet.There were 8 studies about the change of plasma triglyceride levels in mice/rats after high-fat diet,subgroup analysis was performed according to different subjects:the group of mice:SMD:2.12,95% CI:1.14~3.10,P<0.0001,the group of rats:SMD:1.26,95% CI:0.48~2.03,P=0.002,the results showed that the plasma triglyceride levels of mice/rats increased after high-fat diet.Conclusion High fat diet can lead to the change of intestinal micro ecological structure in mice/rats.The change of intestinal micro ecological structure may play an important role in the pathogenesis of metabolic diseases such as obesity and hyperlipidemia.