雌激素缺乏对高脂饮食引发非酒精性脂肪肝小鼠肠道菌群调控的宏基因组学研究OA

Objective To draw an intestinal microbiota map of estrogen deficiency on non-alcoholic fatty liver disease(NAFLD)caused by high-fat diet through metagenomic sequencing.Methods Eighteen C57/6 female mice were randomly divided into a control group(common maintenance feed),a model group(high-fat feed),and an ovariectomy group(ovariectomy+high-fat feed).After 10 weeks of feeding,serum,liver and feces were collected,body weight,liver weight was measured and serum estradiol(E2),alanine aminotransferase(ALT)and aspartate aminotransferase(AST)and liver triglyceride were detected.HE and oil red O staining were used to evaluate the pathological changes and accumulation of lipid droplet of liver tissue.Metagenomic sequencing was performed to analyze the changes of intestinal microbiota.Results The serum E2 level in the ovariectomy group was significantly lower than that in the control group and the model group(P＜0.001),indicating suc-cessful construction of the estrogen deficiency model.Compared with the control group,the body weight,liver weight,serum ALT,AST,and liver TG of the model group significantly increased(P＜0.05);whereas ovariec-tomy significantly exacerbated these changes(P＜0.05).Histological observations showed that a high-fat diet induced hepatic steatosis in the model group,while ovariectomy further exacerbated this pathological process.According to metagenomics analysis,both the model group and the ovariectomy group showed a significant de-crease in the alpha diversity of intestinal microbiota(P＜0.05),and the abundance of Bacillota,which is the main colonizing bacterium in the intestine,decreased in model group and further decreased after ovariectomy.The analysis of the intestinal microbiota species composition showed significant differences among the groups.Combined with LEfSe analysis,it was identified that the abundance of Thioalkalivibrio increased and Akkermansia_muciniphila decreased in model group,while Akkermansia_muciniphila increased after ovariectomy.Pathway prediction analysis identified that lipid metabolism pathway,energy metabolism pathway in ovariectomy group were upregulated compared with the control group and model group.Spearman correlation analysis revealed that the relative abundance of Odoribacter genus was positively correlated with indicators related to liver injury and steatosis,while Lepagella genus was negatively correlated(P＜0.05).Only Akkermansia genus showed a nega-tive correlation with estrogen level(P＜0.05).Conclusion Estrogen deficiency exacerbate hepatic steatosis in-duced by high-fat diet and it is related to exacerbating intestinal microbiota imbalance.Akkermansia_muciniphila may be a key bacterial species responsible for characteristic changes in the gut microbiota of NAFLD mice under estrogen deficiency.