title: New insights into bile acid malabsorption.
abstract: Bile acid malabsorption occurs when there is impaired absorption of bile acids in the terminal ileum, so interrupting the normal enterohepatic circulation. The excess bile acids in the colon cause diarrhea, and treatment with bile acid sequestrants is beneficial. The condition can be diagnosed with difficulty by measuring fecal bile acids, or more easily by retention of selenohomocholyltaurine (SeHCAT), where this is available. Chronic diarrhea caused by primary bile acid diarrhea appears to be common, but is under-recognized where SeHCAT testing is not performed. Measuring excessive bile acid synthesis with 7α-hydroxy-4-cholesten-3-one may be an alternative means of diagnosis. It appears that there is no absorption defect in primary bile acid diarrhea but, instead, an overproduction of bile acids. Fibroblast growth factor 19 (FGF19) inhibits hepatic bile acid synthesis. Defective production of FGF19 from the ileum may be the cause of primary bile acid diarrhea.
authors.affiliation: Section of Hepatology & Gastroenterology, Department of Medicine, Imperial College London, Du Cane Road, London W12 0HS, UK. i.johnston@imperial.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Johnston
authors.forename: Jonathan
authors.initials: J
authors.lastname: Nolan
authors.forename: Sanjeev S
authors.initials: SS
authors.lastname: Pattni
authors.forename: Julian R F
authors.initials: JR
authors.lastname: Walters
mesh_terms: D000837:Anion Exchange Resins / Q000627:therapeutic use; D002793:Cholic Acids / Q000096:biosynthesis* / Q000378:metabolism; D003967:Diarrhea / Q000175:diagnosis* / Q000209:etiology* / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000378:metabolism; D006801:Humans; D008286:Malabsorption Syndromes / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D015398:Signal Transduction; D013656:Taurocholic Acid / Q000031:analogs & derivatives
chemical_list: D000837:Anion Exchange Resins; D002793:Cholic Acids; C117476:FGF19 protein, human; D013656:Taurocholic Acid; D005346:Fibroblast Growth Factors; C033638:23-seleno-25-homotaurocholic acid