ABSTRACT
This study aimed to investigate the recovery effect of Zuogui Jiangtang Qinggan Prescription on intestinal flora homeostasis control and intestinal mucosal barrier in type 2 diabetes mellitus(T2DM) with nonalcoholic fatty liver disease(NAFLD) induced by a high-fat diet. NAFLD was established in MKR transgenic mice(T2DM mice) by a high-fat diet(HFD), and subsequently treated for 8 weeks with Zuogui Jiangtang Qinggan Prescription(7.5, 15 g·kg~(-1)) and metformin(0.067 g·kg~(-1)). Triglyceride and liver function were assessed using serum. The hematoxylin-eosin(HE) staining and Masson staining were used to stain the liver tissue, while HE staining and AB-PAS staining were used to stain the intestine tissue. 16S rRNA sequencing was utilized to track the changes in the intestinal flora of the mice in each group. Polymerase chain reaction(PCR) and immunofluorescence were used to determine the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-1. The results demonstrated that Zuogui Jiangtang Qinggan Prescription increased the body mass of T2DM mice with NAFLD and decreased the hepatic index. It down-regulated the serum biomarkers of liver function and dyslipidemia such as alanine aminotransferase(ALT), aspartate transaminase(AST), and triglycerides(TG), increased insulin sensitivity, and improved glucose tolerance. According to the results of 16S rRNA sequencing, the Zuogui Jiangtang Qinggan Prescription altered the composition and abundance of the intestinal flora, increasing the relative abundances of Muribaculaceae, Lactobacillaceae, Lactobacillus, Akkermansia, and Bacteroidota and decreasing the relative abundances of Lachnospiraceae, Firmicutes, Deslfobacteria, Proteobacteria, and Desulfovibrionaceae. According to the pathological examination of the intestinal mucosa, Zuogui Jiangtang Qinggan Prescritpion increased the expression levels of the tight junction proteins ZO-1, Occludin, and Claudin-1, promoted intestinal mucosa repair, protected intestinal villi, and increased the height of intestinal mucosa villi and the number of goblet cells. By enhancing intestinal mucosal barrier repair and controlling intestinal microbiota homeostasis, Zuogui Jiangtang Qinggan Prescription reduces intestinal mucosal damage induced by T2DM and NAFLD.