Advancements in Laboratory Testing for Bile Acid Profiling and Clinical Implications

Abstract

Bile acids are a diverse family of amphipathic sterols synthesized from cholesterol, primarily in the liver. They play crucial roles in digestion, lipid absorption, and various signaling pathways. Bile acid synthesis and metabolism involve complex processes, including the classical and alternative pathways, conjugation, and biotransformation by gut microbiota. Bile acids undergo enterohepatic circulation, and their homeostasis is maintained through a delicate balance of synthesis, reabsorption, and excretion. Receptors such as FXR and TGR5 are key regulators of bile acid signaling and metabolism. Profiling bile acids has become increasingly important for understanding their roles in health and disease. Liquid chromatography-mass spectrometry (LC-MS) is the most widely used technique for bile acid detection and quantification. However, challenges such as high costs and complex sample preparation have limited its clinical adoption. Bile acid profiles exhibit significant alterations in various diseases, including type 2 diabetes mellitus, non-alcoholic fatty liver disease, cholestatic liver disease, inflammatory bowel disease, Alzheimer's disease, and cancer. These changes often precede conventional diagnostic markers, highlighting the potential of bile acid profiling as a tool for early disease detection and monitoring. Despite the promise of bile acid profiling, translating research findings into clinical practice faces several barriers, such as interspecies differences in bile acid metabolism and inconsistencies in study design and methodology. Overcoming these challenges and leveraging advances in technology and artificial intelligence could pave the way for personalized medicine approaches based on comprehensive bile acid profiling.