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.