Bile acid malabsorption in inflammatory bowel disease.

Area of Science:

• Gastroenterology
• Immunology
• Metabolic Disorders

Background:

• Bile acid malabsorption (BAM) is a common yet underestimated complication in inflammatory bowel diseases (IBD), particularly affecting the ileum.
• BAM can occur even in IBD patients without ileal disease or in remission, with its clinical significance often unappreciated.
• Impaired reabsorption of conjugated bile acids (BAs) via the apical sodium/bile acid cotransporter is the primary cause of BAM in IBD.

Purpose of the Study:

• To review the pathophysiological mechanisms of BAM-related diarrhea in IBD.
• To discuss the role of BAM in IBD pathogenesis and its impact on intestinal health.
• To explore novel findings on bile acid signaling pathways and their influence on immune function and intestinal metabolism in IBD.

Main Methods:

• Literature review of pathophysiological mechanisms of BAM in IBD.
• Analysis of the role of bile acid metabolism and signaling in IBD pathogenesis.
• Discussion of diagnostic challenges and novel findings in bile acid research.

Main Results:

• BAM leads to steatorrhea, altered intestinal motility, and changes in gut microbiota.
• BAM is prevalent in Crohn's ileitis and post-ileal resection, but also occurs in other IBD contexts.
• Bile acid signaling pathways interact with immune functions and intestinal metabolism, influencing IBD.

Conclusions:

• BAM is a significant but often neglected factor in IBD management.
• Routine laboratory assessment of BAM in IBD is limited by cost and logistical barriers.
• Understanding BA signaling is crucial for unraveling IBD pathogenesis and developing new therapies.