Gut microbiota and metabolic-associated steatosis liver disease: Unveiling mechanisms and opportunities for therapeutic intervention.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become a leading cause of chronic liver disease, closely linked with metabolic syndrome. Recent evidence spotlights the gut-liver axis as a major player in MASLD pathogenesis. Dysbiosis of gut microbiota alters the intestinal barrier and enhances endotoxemia, hepatic inflammation, insulin resistance and fibrosis. Microbial metabolites including short-chain fatty acids, bile acids and ethanol impact host metabolism and immunity, and their dysregulation contributes to disease progression. This review summarises the mechanistic associations between dysbiosis and MASLD involving altered microbial composition, leaky gut, toll-like receptor signalling and immune dysregulation. It also reviews microbially targeted therapeutic strategies, such as probiotics, prebiotics, synbiotics, faecal microbiota transplantation, diet changes, and postbiotic metabolites. Although these interventions may have clinical potential, the heterogeneity of outcomes highlights the interindividual nature of the microbiome and warrant personalized interventions. Developments in multi-omics and precision medicine provide possibilities to discover microbial biomarkers and customize therapeutic approach. Resolving methodological heterogeneity and providing a clear definition of MASLD-related dysbiosis are key for translating microbiome science into the clinic. In conclusion, modulation of gut microbiota is an emerging strategy for the adjunctive treatment of MASLD alongside lifestyle and pharmacologic therapies.