Altered Bile Acid Transport in Liver Disease

Background/Objectives: Bile acids, synthesized from cholesterol in the liver, are amphipathic molecules that play an integral role in lipid digestion and absorption, while also serving as systemic endocrine hormones. They continuously undergo enterohepatic circulation, where they interact with various transporter proteins. Dysregulated bile acid transport is associated with the pathogenesis of liver disease. This review summarizes the key findings relating to bile acid transport expression and activity in the pathogenesis of liver disease. Methods: A review of the literature was performed using PubMed and relevant terms including, but not limited to, "bile acid transporters", "liver disease", and "bile acid uptake and efflux". Studies published in peer-reviewed journals relevant to this review were considered and reviewed. Results: Within the gut and liver, several key bile acid and xenobiotic transporters within the enterohepatic circulation are dysregulated. The directionality and extent of changes are cell- and disease-specific. Many of the regulatory processes are driven by changes in bile acid signaling, although further work is needed to expand on post-translational modification of bile acid transporters in liver disease. Conclusions: Bile acid transporters are dynamically regulated in liver diseases with distinct etiologies. Therefore, restoring BA transporter function represents an actionable therapeutic approach to liver disease.