Bile acid disease: the emerging epidemic.
OBJECTIVE
Our objective was to review advances in bile acids in health and disease published in the last 2 years. Bile acid diarrhea (BAD) is recognized as a common cause of chronic diarrhea, and its recognition has been facilitated by development of new screening tests.


RESULTS
Primary BAD can account for 30% of cases of chronic diarrhea. The mechanisms leading to BAD include inadequate feedback regulation by fibroblast growth factor 19 (FGF-19) from ileal enterocytes, abnormalities in synthesis or degradation of proteins involved in FGF-19 regulation in hepatocytes and variations as a function of the bile acid receptor, TGR5 (GPBAR1). SeHCAT is the most widely used test for diagnosis of BAD. There has been significant validation of fasting serum FGF-19 and 7 α-hydroxy-cholesten-3-one (C4), a surrogate measure of bile acid synthesis. Bile acid sequestrants are the primary treatments for BAD; the farnesoid X-receptor-FGF-19 pathway provides alternative therapeutic targets for BAD. Bile acid-stimulated intestinal mechanisms contribute to the beneficial effects of bariatric surgery on obesity, glycemic control and the treatment of recurrent Clostridium difficile infection.


CONCLUSIONS
Renewed interest in the role of bile acids is leading to novel management of diverse diseases besides BAD.
Division of Gastroenterology and Hepatology, Mayo Clinic, Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), Rochester, Minnesota, USA.
Ibironke
I
Oduyebo
Michael
M
Camilleri
D000930:Antidiarrheals / Q000627:therapeutic use; D001647:Bile Acids and Salts / Q000502:physiology*; D002908:Chronic Disease; D003967:Diarrhea / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism* / Q000628:therapy; D004764:Enterohepatic Circulation / Q000502:physiology; D005346:Fibroblast Growth Factors / Q000378:metabolism; D015390:Gastric Bypass; D006801:Humans; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery
D000930:Antidiarrheals; D001647:Bile Acids and Salts; C117476:FGF19 protein, human; D005346:Fibroblast Growth Factors