Development and Validation of a Risk Prediction Model for Cardiac Surgery-associated Acute Kidney Injury Based on the Gut-Kidney Axis, Incorporating Gut Microbiota and Their Metabolites

This is a single-center prospective observational cohort study enrolling adult patients scheduled for cardiac surgery. Multi-timepoint clinical indicators, stool samples for gut microbiota and metabolomics profiling and artery blood will be collected before and after surgery. We aim to construct and validate a multi-dimensional preoperative predictive model for CSA-AKI based on clinical, microbial and metabolic signatures. Meanwhile, this research will explore the potential mediating role of the gut-kidney axis in the pathogenesis of cardiac surgery-associated acute kidney injury, and provide novel mechanistic evidence for early risk stratification and intervention of CSA-AKI.