A Comprehensive Analysis of Serum and Urine Bile Acid Profiles in Chronic Kidney Disease: An Exploratory Study of Clinical Associations

AIM: Dysbiosis contributes to systemic inflammation and the accumulation of uremic toxins, leading to end-stage kidney disease. However, the role of bile acids (BAs), key metabolic products of the gut microbiota, in the pathophysiology of chronic kidney disease (CKD) remains incompletely understood. Profiling BA metabolism may provide valuable insights into CKD pathophysiology and help in identifying novel therapeutic targets. METHODS: This cross-sectional study recruited 29 patients with advanced CKD and 30 sex- and age-matched individuals with normal renal function (NRF). Serum and urine BA profiles were compared between the two groups. RESULTS: Total BA levels in serum did not differ significantly between the CKD and NRF groups. However, patients with CKD exhibited lower serum levels of unconjugated BAs and significantly higher levels of sulfate-conjugated BAs than those with NRF. In contrast, urinary total BA levels and most BA subgroups were significantly lower in patients with CKD. Additionally, the serum levels of ursodeoxycholic, chenodeoxycholic acid and sulfated-conjugated BAs were associated with a decline in the estimated glomerular filtration rate, even after adjusting for demographic factors and diabetes status. CONCLUSION: This study provides a comprehensive analysis of serum and urinary BAs in patients with advanced CKD. Our findings highlight the association between specific BAs and CKD, suggesting a distinct pathophysiological role of BA metabolism in CKD progression.