The Effect Of PTE On Lipid Metabolism And Inflammation Of Obese Mice Studying Based On Gut Microbiota

Studies show there are many factors are accountable for obesity,and even though the primary reason is an imbalance between dietary energy intake and expenditure.And recent studies show that obesity is closely related to the gut microbiota.The disorganized gut microbiota can trigger obesity by causing low-grade systemic inflammation and abnormal lipid metabolism.Diet is a main factor that can affect gut microbiota.Therefore,it is important to develop a safe and effective dietary supplement that can improve obesity.Pu-er tea is from the leaves of Camellia sinensis,which has many biological activities and is beneficial for health,like anti-inflammatory,anti-oxidant,anti-obesity properties and so on.However,the relationship among pu-er tea extract(PTE),obesity and gut microbioat is still unclear,so we explore that through the following aspects:1.First animal experiment : 8 weeks old male C57BL/6J mice was used to examine the preventive effect of PTE on obesity under a high-fat diet.Body weight and food intake were assessed weekly.At the end of the study,liver and fat pads(epididymal adipose tissues and subcutaneous fat)were measured after which they were killed.The results showed that PTE can significantly reduce body weight gain,fat accumulation,adipocyte volume,hepatic fat infiltration,and the 0.4% PTE have most significant effect on body weight losing,which achieved an effect of reducing body weight by 23%.The mRNA level expression of FAS and SREBP in the liver of the mice closely related to lipid metabolism,which were determined by quantitative Real-time PCR(qRT-PCR).The results showed that PTE can significantly reduce these two genes at the mRNA levels expression under high-fat diet conditions.The concentration of free fatty acid in the blood of mice of each group was detected by enzyme linked immunosorbent assay(ELISA).The results showed that PTE can significantly reduce the lipid levels under high-fat diet conditions,and the improvement effect was most significant with 0.4% PTE.By measuring the fasting blood glucose and glucose tolerance test before the mice were killed,the results showed that PTE can significantly improve glucose metabolism and lipid metabolism under high-fat diet conditions,and the most significant improvement was achieved with 0.4% PTE.Through the measurement of food intake and caloric intake of mice in each group,the results showed that PTE did not cause significant differences on the food intake of mice in each group.2.The ileal permeability and the inflammation of adipose tissue were detected by qRT-PCR.ELISA was used to detect the concentration of Lipopolysaccharides(LPS)in blood.The results showed that PTE could significantly improve the permeability of ileum and reduce serum LPS concentration under high-fat diet.And the level of inflammatory factors in adipose tissue were also reduced and dose-dependent PTE concentration under high fat diet,the 0.4% PTE being the most significant improvement under high fat diet.3.Second animal experiment: In order to confirm whether the effect of PTE on body weight loss is related to gut microbiota,a fecal transplant experiment was performed.The fecal donor mice were 8 weeks old C57BL/6J mice that had been treated with 4 weeks under the corresponding experimental conditions.The fecal recipient mice were 8 weeks old C57BL/6J mice under a high-fat diet condition,and the entire experimental period was 8 weeks.Body weight were assessed weekly.After the end of the experiment,the mice were sacrificed.The weight of subcutaneous fat,epididymal fat and liver were assessed,the HE staning of the fat and liver were observed.The results showed that compared with the feces of donor mice under high fat diet,the feces of donor mice were fed under control diet,or the feces of donor mice under high fat diet administration with PTE can significantly reduce body weight gain,fat accumulation,adipocyte volume,and hepatic fat infiltration in recipient mice.By measuring the fasting blood glucose and glucose tolerance test before the mice were killed,the results also showed that compared with the feces of donor mice under high fat diet,the feces of donor mice were fed under control diet,or the feces of donor mice under high fat diet administration with PTE can significantly improve glucose metabolism of recipient mice under the high-fat diet.4.By collecting the feces of the mice at the end of the first animal experiment,and then performing 16 S rRNA sequencing,the results showed that PTE can increase the abundance of the following bacterium at the corresponding classification level: Segetibacter(genus),Armatimonadetes(phylum),JG30-KF-CM45(order),OPB35 soil group(class),Subgroup 22(class),Gemmatimonas(genus),Haliangium(genus),unidentified Cyanobacteria(class),Allobaculum(genus),unidentified Acidobacteria(class),Anaerolineaceae(family),Clostridiales vadinBB60 group(family),DA111(family),Nitrosomonadaceae(family),Gaiellales(order),Clostridiales(order),Mollicutes RF9(order),Latescibacteria(phylum),Micromonosporaceae(family).Therefore,our results indicate that PTE may prevent HFD-induced obesity by modulating the composition of the gut microbiota in multiple ways.Our results imply that PTE maybe as a supplementation to modulate gut microbiota,improves gut barrier integrity,reduces endotoxemia,and decreases inflammation in fat tissues,and final to protect body from obesity.