Targeting the gut-liver axis with dietary polyphenols to ameliorate metabolic dysfunction-associated steatotic liver disease: advances in molecular mechanisms

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a condition that results from metabolic disorders. In addition to genetic factors, irregular and high-energy diets may also significantly contribute to its pathogenesis. Dietary habits can profoundly alter the composition of gut microbiota and metabolites. Metabolites can be absorbed into the blood and liver via the gut-liver axis in MASLD. Dietary polyphenols are important bioactive compounds in daily diets that can effectively promote human health. Dietary polyphenols have beneficial effects on MASLD of host, but their mechanism of action is still unclear, and clinical translation is difficult and also affected by individual differences. Accumulating evidence suggest that dietary polyphenols can effectively ameliorate MASLD via the gut-liver axis. In this review, the effects of dietary polyphenols on the gut-liver axis in MASLD models were systematically summarized. Dietary polyphenols can affect the gut microbiota and its metabolites, which can effectively restore the damaged gut barrier. Dietary polyphenols can regulate lipid metabolism, inflammation, autophagy, apoptosis-related signaling pathways, and key gene expression in the liver, thereby alleviating MASLD-induced liver damage. These findings broadens our understanding of how polyphenols improve metabolic disorders, and provides valuable insights for future studies of dietary polyphenols.