| Objective: Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease in the world,involving a series of liver phenotypes from simple hepatic steatosis,non-alcoholic steatohepatitis and cirrhosis,but there is no effective treatment drug at present.Previous studies have proved that xylo-oligosaccharide is a prebiotic that can regulate intestinal flora to improve non-alcoholic fatty liver disease,but the mechanism is not clear.We studied the effect of xylo-oligosaccharide on intestinal flora of non-alcoholic fatty liver disease,and further explored the changes of intestinal metabolites in mice.The correlation between microflora and metabolites and its possible effect on nonalcoholic fatty liver disease were analyzed.Methods: The 5-week-old SPF male C57/BL6 J mice were randomly divided into 3 groups according to statistical methods: Control group(CK),high fat diet group(HFD)and xylooligosaccharide treatment group(XOS),the control group was given ordinary clean feed,and the other two groups were given special feed containing 60% fat to establish nonalcoholic fatty liver model.XOS group was given xylooligosaccharide 0.35 g/kg daily,HFD group was given the same amount of normal saline.Collect excrement in mice after16 weeks,blood,liver,blood biochemical analysis,liver H.E staining and oil red staining,the severity of the disease by scoring system,at the same time,through the analysis of the16 s microbial sequencing technology distribution,structure of intestinal flora in mice,through targeted metabolomic analysis of the change of intestinal metabolites.Results: Blood biochemical analysis showed that ALT,AST and TG in HFD group increased significantly compared with control group,but decreased significantly after xylooligosaccharide treatment(P<0.05);By observing H.E staining and oil red staining of the liver of the three groups of mice,compared with the MICE in the CK group,there were obvious lipid droplets in the liver cells of the XOS group and HFD group,but the lipid droplets in the XOS group were significantly reduced compared with the HFD group,and no obvious necrosis of liver cells or inflammatory cell infiltration was found in all of them.According to 16 S r DNA microbial sequencing analysis,α diversity index Shannon index showed that the microbial abundance in HFD and XOS groups was higher than that in CK group,but there was no significant difference between HFD and XOS group.PCo A analysis and Adonis analysis(P<0.001)showed that there were significant differences in the structure and distribution of microflora among the three groups.K-w analysis could be used to determine the difference of bacterial flora between the three groups at different levels(P< 0.05),4 different species were detected at phylum level,37 different species were detected at family level,and 92 different species were detected at genus level among 3groups.LEf Se analysis revealed a total of 15 distinguishing features in XOS and HFD groups,and 34 distinguishing features in CK and HFD groups(P<0.05 LDA> 3);PICRUSt pathway analysis predicted the composition of microbial gene functions,including sphingomyelin metabolism,glycerophospholipid metabolism,PPAR signaling pathway,etc.In metabolomics,a total of 371 differentially varied metabolites were identified in XOS group and HFD group by OPLS-DA and T test,while 775 differentially varied metabolites were identified in HFD group and CK group,and KEGG functional enrichment analysis was performed for the differentially varied metabolites.In XOS group and HFD group,11 metabolic pathways(P<0.05),13 metabolic pathways were obtained in CK group and HFD group.Spearman analysis showed that sphingine,sphingine1-phosphate and Glycerophosphocholine were associated with various intestinal flora.Conclusion: Non-alcoholic fatty liver can cause changes in intestinal flora and metabolites.After xylo-oligosaccharide intervention,the abundance of differential intestinal flora of model group mice was closer to that of control group.In addition,LEf SE analysis obtained biomarkers of different class levels of non-alcoholic fatty liver and predicted the function of differential microorganisms.It provides an important reference for xylo-oligosaccharide to improve NAFLD from the perspective of bacterial community.Changes in sphingine,sphingine1-phosphate and Glycerophosphocholine may affect the progression of nonalcoholic fatty liver disease,and the mechanism remains to be further studied. |
