Update on Bile Acid Malabsorption: Finally Ready for Prime Time?

Area of Science:

• Gastroenterology
• Hepatology
• Internal Medicine

Background:

• Bile acids (BAs) play crucial roles in digestion and metabolism.
• Bile acid malabsorption (BAM) is increasingly recognized as a significant clinical entity.
• Understanding BA homeostasis is vital for various gastrointestinal and liver diseases.

Purpose of the Study:

• To review the current understanding of bile acid malabsorption (BAM).
• To cover prevalence, pathophysiology, disease associations, and emerging treatments for BAM.
• To highlight recent advancements in the field of bile acid research.

Main Methods:

• Literature review of recent studies on bile acid malabsorption.
• Analysis of molecular mechanisms underlying BAM.
• Evaluation of new diagnostic and therapeutic strategies.

Main Results:

• Bile acids influence water transport through intracellular mediators and aquaporin channels.
• Novel molecular mechanisms of BAM are identified in inflammatory bowel disease, even without ileal disease.
• BAM is implicated as a causative mechanism in microscopic colitis.
• New diagnostic tests, including serum C4 and fecal 48-h BA excretion, have been introduced.
• Stimulated FGF19 levels show higher sensitivity for BAM detection than fasting samples.
• Investigational farnesoid X receptor (FXR) agonists present a potential daily oral treatment alternative to bile acid sequestrants.

Conclusions:

• Bile acid malabsorption is a complex condition with diverse underlying mechanisms.
• Advancements in diagnostics are improving the detection of BAM.
• Emerging therapeutic targets, such as FXR agonists, promise novel treatment approaches for BAM.
• The biological significance of bile acids extends across multiple medical disciplines.