Gut microbiota: a novel key player in urinary stone formation - from oxalate metabolism to systemic regulation.

Kidney stones represent a globally prevalent disease with a rising incidence associated with multiple factors, including obesity and metabolic syndrome. While traditional research has primarily focused on dietary nutrition and metabolic abnormalities, recent years have seen growing recognition of the gut microbiota as a key novel regulator in stone formation. Accumulating cross-sectional evidence suggests that kidney stone patients are often associated with alterations in gut microbiota composition and function compared with healthy individuals. The gut microbiota may influence kidney stone formation risk through multiple potential mechanisms, including affecting oxalate metabolism, calcium-phosphorus absorption, short-chain fatty acid and bile acid pathways, and regulating systemic inflammatory and immune states. More importantly, this "gut-kidney axis" function of the gut microbiota holds clinical translational potential, suggesting that targeted microbial interventions may emerge as novel strategies for preventing and treating kidney stones. This review explores the association between gut microbiota and kidney stones, discussing clinical evidence, underlying mechanisms, and intervention strategies while analyzing current challenges and outlining future research directions.