Effects of shenling baizhu powder herbal formula on intestinal microbiota in high-fat diet-induced NAFLD rats

Worldwide, non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease closely associated with obesity, diabetes and other metabolic diseases. Shenling Baizhu powder (SLBZP), a formulation of a variety of natural medicinal plants, has hepatoprotective properties and clinical efficacy in treating non-infectious intestinal disease. SLBZP has improved NAFLD symptoms; however, its mechanism of action is unknown. We established an NAFLD model in rats given a high-fat diet (HFD), administered different interventions and measured serum biochemical indices and inflammatory factors. Liver tissues were stained with hematoxylin and eosin (HE) and oil red O, and colon tissues were analyzed by immunohistochemistry. The expression profiles of liver TLR4 pathway related protein was confirmed by western blotting. Changes in intestinal microbiota composition were analyzed using a 16S rDNA sequencing technique. Of note, SLBZP effectively reduced body weight in HFD-fed rats (p < 0.05). Serum biochemical analysis indicated that SLBZP decreased the serum level of total cholesterol (TC) and improved liver function. Additionally, SLBZP decreased the serum level of endotoxin, tumor necrosis factor α (TNF-α), interleukin-1β (IL-β) (p < 0.05), and decreased the expression of TLR4 pathway related protein. Pathological examination showed that SLBZP alleviates hepatic steatosis and repairs colon mucosa. Microbiome analysis revealed that SLBZP improved the abundance of intestinal microbiota. In taxonomy-based analysis, compared with control rats, SLBZP-treated rats showed obvious changes in intestinal microbiota composition. Moreover, SLBZP increased the relative abundance of short-chain fatty acid (SCFA)-producing bacteria, including Bifidobacterium and Anaerostipes. Taken together, these results suggest that the effects of SLBZP against NAFLD may be related to the increased abundance of beneficial gut microbiota and decreased levels of LPS in the portal vein.