High concentration and retained amidation of fecal bile acids in patients with active ulcerative colitis.

Fecal bile acid profiles of 14 patients with ulcerative colitis in the active phase were analyzed to study the potential significance of bile acids in the pathophysiology of this disease, and the results were compared with those in 12 healthy controls. The excretion levels of total bile acids (mean +/- SD) in patients were higher than in controls, 445.1 +/- 392.1 vs 215.5 +/- 148.0 mumol/day, 3.1 +/- 1.7 vs 1.6 +/- 1.0 mumol/g wet feces (P less than 0.05), and 17.2 +/- 9.2 vs 12.4 +/- 13.3 mumol/g dry feces. Fecal profiles of individual bile acids showed higher levels of primary bile acids (52 +/- 27%) in patients compared to those (26 +/- 21%) in controls. Proportions of glycine and taurine conjugates in patients (26 +/- 24%) were higher than in controls (5 +/- 2%) (P less than 0.05), whereas proportions of unconjugates and sulfates were lower in patients than in controls. Accordingly the extent of deconjugation and dehydroxylation of bile acids was lower in patients than in controls. These trends were prominent in patients with more severe disease activity. A high concentration of bile acids in the intestine may have a significant role in the pathophysiology of ulcerative colitis at active phase.