Enhanced bile acid detection and analysis in liver fibrosis with pseudo-targeted metabolomics

Bile acids (BAs) are essential signaling molecules that engage in host and gut microbial metabolism, playing a crucial role in maintaining organismal stability. Liquid chromatography-mass spectrometry (LC-MS) is a widely employed technique for metabolite analysis in biological samples due to its high sensitivity, excellent specificity, and low detection limits. This method has emerged as the mainstream approach for the detection and analysis of BAs. Pseudo-targeted analysis combines the advantages of both untargeted and targeted metabolomics methodologies. In this study, we developed a comprehensive and rapid method for detecting and analyzing BAs using LC-MS technology, applied to liver samples from bile duct-ligated (BDL) mice exhibiting liver fibrosis. A self-constructed database containing 488 BAs was established, and raw data from universal metabolome standard (UMS) were acquired using UHPLC-Q/TOF-MS. A total of 172 BA compounds were characterized, including 74 free BAs and 158 BAs were successfully detected using the high-coverage assay established with UHPLC-QQQ-MS. This assay was employed in the BDL liver fibrosis mouse model, where statistical analysis tools identified 20 differential BAs in the livers of affected mice. The development of this rapid method signifies a substantial advancement in the field, illustrating its utility in identifying differential BAs and enhancing our understanding of liver fibrosis. Furthermore, the high-coverage assay's ability to accurately analyze a diverse range of BAs could substantially aid in diagnosing and treating liver diseases.