Pediatric metabolic dysfunction-associated steatotic liver disease and the gut microbiome: from research landscape to targeted modulation.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease, has become the most common form of chronic liver disease in children. The spectrum of pediatric MASLD ranges from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and in rare cases, hepatocellular carcinoma. Its pathogenesis involves a complex interplay among genetic, epigenetic, and environmental factors, along with alterations in the gut microbiota and its associated metabolites. Given the staggering prevalence and the distinct etiopathogenesis of pediatric MASLD, characterization of the gut microbiota and microbial products could facilitate the development of diagnostic tools and inform targeted therapeutic strategies. Current research on the gut microbiome in the context of pediatric MASLD is limited by small sample size, inadequate use of liver biopsy, methodological inconsistencies in sequencing, and confounding effects from metabolic comorbidities. In this review, we summarize clinical studies on alterations in the gut microbiota and microbial products (short-chain fatty acids, bile acids, and ethanol) that impact the pathogenesis of pediatric MASLD. We discuss the therapeutic potential of dietary modification, pharmacological treatments, and probiotics in improving disease progression by summarizing current clinical studies. Enhancing our understanding of the gut-liver axis may aid in the development of effective therapeutic strategies for pediatric MASLD.