Dissecting Molecular Mechanisms in Bile Acid Diarrhea.

It was previously demonstrated that patients with bile acid (BA) diarrhea have low fasting serum levels of the ileal hormone--fibroblast growth factor-19 (FGF-19). In this paper, the authors demonstrate a positive correlation between ileal transcripts of FGF-19 and (75)SeHCAT retention, providing further evidence of FGF-19 deficiency as an explanation for BA diarrhea. Variants in KLB and FGFR4 genes (that determine the functional re-uptake of BA in the portal circulation by hepatocytes) are also demonstrated to be associated with (75)SeHCAT retention, confirming a second potential mechanism for the development of BA diarrhea.