Bile salt hydrolase: a key player in gut microbiota and its implications for metabolic dysfunction-associated steatotic liver disease.

Abstract

The rising prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) poses a significant global public health challenge. Bile acids (BAs), synthesized in the liver and further metabolized in the gut, are essential in maintaining host metabolic homeostasis. Bile salt hydrolase (BSH), an enzyme produced by the gut microbiota, catalyzes the hydrolysis of conjugated BAs, thus regulating the balance between primary and secondary BAs. Growing evidence suggests that BSH activity is intricately linked to the pathogenesis of MASLD. This review comprehensively examines the structural and functional properties of BSH enzymes, their distribution among gut microbial communities, and current methodologies for assessing BSH expression and activity. Furthermore, it highlights the alterations in BSH observed in MASLD and explores the potential mechanistic pathways involved, offering a foundation for the development of novel diagnostic and therapeutic strategies.