肠道菌群及代谢产物对高脂饮食介导的非酒精性脂肪肝的潜在影响

The Potential Effect of Intestinal Flora and Metabolites on High-Fat Diet-Mediated Nonalcoholic Fatty Liver Disease

摘要: 目的：非酒精性脂肪肝目前是世界范围内最常见的慢性肝病，发病机制尚未明了。有研究表明肠道菌群及代谢产物可通过门静脉循环影响疾病的发生发展，但目前没有定论，本次研究了非酒精性脂肪肝小鼠中肠道菌群及代谢产物的改变，并探讨了其可能对非酒精性脂肪肝的影响。方法：将小鼠随机分为高脂饮食组(HFD组)和对照组(CK组)，通过高脂饮食诱导非酒精性脂肪肝模型，检测小鼠谷丙转氨酶(ALT)、谷草转氨酶(AST)、甘油三脂(TG)水平，通过H.E染色和油红染色观察肝脏病理。通过16S微生物测序技术及代谢组学分析小鼠体内肠道菌群和代谢产物的变化，推测可能的作用。结果：与CK组比较，HFD组中ALT、AST、TG水平明显降低(P < 0.05)，观察肝脏病理发现有明显脂肪变性。通过PCoA分析及Adonis分析(P < 0.001)发现两组菌群结构及分布有显著差异；通过Wilcoxon分析得到两组在不同分类阶元的差异菌群(P < 0.05)，Lactobacillus及Coriobacteriaceae_UCG_002在CK组中升高，而Prevotellaceae在HFD组中升高。代谢组学分析发现两组间有明显差异，在CK组中有156种产物升高。两组学联合分析，肠道代谢产物如甘油磷酸胆碱，鞘氨醇与部分细菌有显著相关性，可能影响非酒精性脂肪肝的进展。结论：高脂饮食诱导的非酒精性脂肪肝可以引起肠道菌群及代谢产物的紊乱，可能通过鞘脂代谢、甘油磷酸胆碱代谢等途径影响非酒精性脂肪肝的进展，其中机制有待于进一步研究。

Abstract: Objective: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The pathogenesis is unclear. Some studies have shown that intestinal flora and metabo-lites can affect the occurrence and development of disease through portal vein circulation, but there is no conclusion at present. This study studied the changes of intestinal flora and metabolites in mice with non-alcoholic fatty liver disease, and discussed their possible effects on non-alcoholic fatty liver disease. Methods: Mice were randomly divided into high-fat diet group (HFD group) and con-trol group (CK group). Non-alcoholic fatty liver model was induced by high-fat diet, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride (TG) were de-tected. Liver pathology was observed by H.E staining and oil red staining. The changes of intestinal flora and metabolites in mice were analyzed by 16S microbial sequencing technology and metabo-nomics, and the possible effects were predicted. Results: Compared with CK group, the levels of ALT, AST and TG in HFD group were significantly lower (P < 0.05), liver pathology showed obvious steato-sis. According to PCoA analysis and Adonis analysis (P < 0.001) significant differences were found in the structure and distribution of bacteria between the two groups. Wilcoxon analysis was used to determine the difference of flora between the two groups in different taxonomic order (P < 0.05), Lactobacillus and Coriobacteriaceae_UCG_002 were increased in CK group, while Prevotellaceae was increased in HFD group. Metabolomics analysis revealed significant differences between the two groups, with 156 products elevated in the CK group. Combined with analysis of the two groups, it showed that intestinal metabolites such as glycerophosphorine and sphingosphenol were signifi-cantly correlated with some bacteria, which may affect the progression of non-alcoholic fatty liver disease. Conclusion: Non-alcoholic fatty liver disease induced by high fat diet can cause disturbance of intestinal flora and metabolites, which may affect the progress of non-alcoholic fatty liver disease through sphingolipid metabolism, glycerophosphatecholine metabolism and other pathways, and the mechanism remains to be further studied.