Liver Metabolomics Reveals The Effect Of Lactobacillus Reuteri On Alcoholic Liver Disease

Objective: To study the effect and potential mechanism of Lactobacillus reuteri on alcoholic liver disease,and to explore a new therapeutic target for alcoholic liver diseaseMethods: 1.Animal experiment: 18 male C57 BL / 6 mice(8-10 week old)were randomly divided into three groups: control group,ethanol group and probiotic group,with 6 mice in each group.Ethanol diet was induced after adaptive feeding for 5 days.The control group was fed with control diet for 8 weeks,the ethanol group and probiotic group were fed with ethanol diet for 8 weeks,and the probiotic group was fed with quantitative Lactobacillus reuteri DSM17938 every day.H&E staining and oil red O staining were used to observe liver inflammation and lipid accumulation of liver.The levels of serum AST,ALT,triglyceride and total cholesterol were measured by biochemical instrument.Serum LPS and TNF-α were detected by enzyme-linked immunosorbent assay(ELISA).Immunohistochemical staining was induced to detect the expression of intestinal tight junction protein ZO-1 and occludin.2. Liver Metabolomics: Ultra-high liquid chromatography and quadrupole time-of-flight tandem mass spectrometry were used to perform liver metabolomics analysis.Mass Hunter qualitative analysis,principal component analysis and orthogonal partial least squares analysis were induced to screen potential biomarkers.The differential metabolites were determined by comparison in HMDB database.KEGG pathway enrichment analysis was induced to find the involved pathway.Results: 1 The body weight,liver weight and liver / body weight ratio of mice in probiotic group were significantly lower than those in alcohol group;2.The inflammatory cell infiltration and lipid accumulation were reversed in probiotic group compared ethanol group;3.The level of serum AST,ALT,triglyceride,total cholesterol,LPS and TNF in probiotic group were reduced than that in alcohol group;4.The expression of intestinal tight junction protein ZO-1 in probiotic group was higher than that in alcohol group;5.23 potential biomarkers were found by metabonomics,and 5 different metabolites were determined by comparison in HMDB database.Several fatty acid metabolic pathways such as linoleic acid metabolism and glycerolipid metabolism were involved.Conclusion: L.reuteri treatment reversed the phenotype of ethanol-induced hepatitis and disorders of fatty acid metabolism(Figure 5C).We speculate that L.reuteri might exert a protective effect on ALD by ameliorating fatty acid metabolism.These findings provide evidence that L.reuteri may serve as a new therapeutic strategy for ALD.