Liver Disease: From Gut Microbiota Dysbiosis and Metabolic Dysfunction to Inflammation, Fibrosis, and Hepatocellular Carcinoma

ABSTRACT BACKGROUND Liver diseases represent a major global health challenge, encompassing a broad spectrum of conditions ranging from metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) to chronic hepatitis, hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Increasing evidence suggests that liver disease progression involves complex interactions among metabolic disturbances, intestinal microbiota, immune responses, oxidative stress, and alterations in cellular homeostasis. The gut–liver axis represents an important biological interface through which intestinal microbial communities, microbial metabolites, and intestinal barrier integrity may influence hepatic physiology and disease progression. In particular, gut microbiota dysbiosis, increased intestinal permeability, and microbial-derived inflammatory mediators may contribute to chronic hepatic inflammation, metabolic dysfunction, and progressive tissue remodeling. Understanding these interconnected mechanisms may provide new perspectives on liver disease pathogenesis, prevention, and therapeutic strategies.