Urinary Antibiotics and Bile Acid Homeostasis in Chinese Adults

Bile acid homeostasis plays a key role in human health. Environmental exposure to antibiotics may influence bile acid homeostasis, but relevant data remain limited in human. We investigated 4247 adults in Shanghai, East China, and measured 31 antibiotics (six human antibiotics (HAs), 10 veterinary antibiotics (VAs), and 15 human/veterinary antibiotics (H/VAs)) and 10 typical bile acids transformed or untransformed microbially (chenodeoxycholic acid, cholic acid, lithocholic acid, ursodeoxycholic acid, and deoxycholic acid, and their respective species conjugated with glycine) in morning fasting urine. Eight concentration ratios of transformed to untransformed bile acids were constructed to indicate the microbial transformations of the bile acids. HAs, VAs, and H/VAs were, respectively, detected in 10.0%, 28.3%, and 58.1% urine samples with the 99th percentiles of creatinine-adjusted concentrations being 2.6 × 102 ug/g, 7.5 ug/g, and 3.2 × 102 ug/g, respectively. Multiple linear regression analysis showed that creatinine-adjusted concentrations of HAs, VAs, and H/VAs as well as eight typical antibiotics, including chlortetracycline, enrofloxacin, ciprofloxacin, ofloxacin, azithromycin, trimethoprim, chloramphenicol, and florfenicol, were associated with bile acids or decreased bile acid ratios. Environmental exposure to antibiotics was likely to disturb bile acid homeostasis in adults by affecting the microbial transformations of the bile acids.