EGCG and Taurine Synergistically Ameliorate Lipid Metabolism Disorder by Modulating Gut Microbiota and PPARα/FAS Signaling Pathway

Background/Objectives: The synergistic effects of epigallocatechin gallate (EGCG) and taurine in modulating lipid metabolism abnormalities in rats were investigated, and along with their potential mechanisms. Methods/Result: Compared to intervention with EGCG/taurine alone, EGCG combined with taurine (1:3) not only reduced triglyceride (TG) generation in HepG2 cells (46.2%, 75.2%, respectively), but also significantly decreased the total cholesterol (TC) (33.3%, 41.8%), low-density lipoprotein cholesterol (LDL-C) (32.3%, 29.2%) in rats, while the high-density lipoprotein cholesterol (HDL-C) increased by 12.7% and 33.5%. In addition, the combination of EGCG and taurine not only inhibited lipogenic enzyme activity, but also enhanced the levels of lipid catabolic enzymes and antioxidant enzymes, and alleviated hepatic injury. Furthermore, it significantly modulated gut microbiota composition by altering the abundances of Bacteroidetes, Firmicutes, and Proteobacteria, improving intestinal flora balance. Metabolomic profiling showed that reducing N-linoleoyl proline, cortisol, and 3-isocholanolic acid, and increasing phospholipid metabolites are the main ways methods for normalizing lipid metabolism in rats. The combination also elevated short-chain fatty acid (SCFA) synthesis, preserving intestinal barrier integrity; it also promoted lipid catabolism and energy expenditure via activating Peroxisome proliferator- activated receptor alpha (PPARα) and suppressing hepatic fatty acid synthase (FAS)- mediated lipogenesis. Conclusion: These findings indicated that EGCG and taurine can synergistically regulate lipid metabolism abnormalities, which may offer a strategy for regulating lipid metabolism anomalies.