Crosstalk along the gut-liver axis in liver disease: Clinical and mechanistic aspects

The gut and liver are anatomically and physiologically interconnected, forming a dynamic axis that plays a central role in the pathogenesis of many liver diseases. Gut-derived factors can influence hepatic injury, inflammation, and fibrosis, acting both as disease modifiers and, in some cases, as primary drivers of aetiology. Conversely, liver-derived factors including bile acids shape microbial ecology, epithelial barrier function, and intestinal immune homeostasis. In this review, we provide an overview of the clinical and mechanistic aspects of the gut-liver axis in hepatology. Using autoimmune, metabolic, and toxic hepatobiliary disorders as model conditions, we highlight recent advances in understanding how intestinal permeability, microbiota composition, and immune signalling contribute to disease initiation and progression. Emphasis is placed on the bidirectional nature of gut-liver interactions and their implications for disease stratification, prevention, and therapy. Finally, we identify key knowledge gaps and outline priorities for future research in this rapidly evolving field.