Lithocholic Acid Species: Metabolism, Signaling Pathways, and Clinical Significance in Enterohepatic Diseases

Secondary bile acids are generated from the metabolism of primary bile acids by intestinal flora and play important roles in lipid digestion, regulation of metabolic homeostasis, and intestinal-hepatic axis signaling. Recent studies indicate that lithocholic acid (LCA) and its derivatives (e.g., 3-oxoLCA and isoLCA) are significantly dysregulated in inflammatory bowel disease, nonalcoholic fatty liver disease, and hepatocellular carcinoma. Consequently, LCA species are emerging as promising biomarkers and potential targets for early diagnosis. This review systematically summarizes the metabolic pathways of LCA species, their distribution and concentrations in human blood, urine, and fecal samples, as well as the progress of recent research studies on enterohepatic disorders, which will serve as a reference for the development of new diagnostic and therapeutic methods in the future.