Glycyrrhizic acid improving the liver protective effect by restoring the composition of Lactobacillus

Glycyrrhizic acid (GL) and its deglycosylated metabolite glycyrrhetinic acid (GA) have been recognized as effective drugs for liver diseases. However, the underlying molecular mechanism of GL and GA remains unclear. Here, CCl4 was used to induce the liver cirrhosis in rat, GL and GA both significantly alleviate the liver fibrosis by decreasing the ALT, AST level in serum. While, only GL was observed to significantly down-regulate the TLR4 and LBP gene expression, which indicated that GL could have direct impact on the intestinal flora. Additionally, 16S rRNA gene sequencing showed that GL especially restore the abundance of Lactobacillus compared with the model group, however, GA has no effect on the cirrhosis-induced gut dysbiosis. Furthermore, PICRUSt analysis showed that GL could improve the relative abundance of phosphotransferase systems and phosphor-glucosidases which may promote the bioavailability of GL. These results may provide novel strategies for prevention and treatment of liver cirrhosis.