OMEPRAZOLE INDUCES ALTERED BILE-ACID METABOLISM

Background-It has been reported that the acidity of gastric contents c ould be an important factor in regulating jejunal flora. Aims-To inves tigate the effects of omeprazole induced changes in gastric pH on jeju nal flora and bile acid metabolism. Methods-Twenty one patients with g astric ulcer and 19 healthy volunteers were studied. Deconjugation of bite acids was detected using a bile acid breath test. Jejunal fluid w as aspirated using a double lumen tube with a rubber cover on the tip and deconjugation was examined using thin layer chromatography. Fat ma labsorption was detected by a triolein breath test. Results-In the bil e acid breath test, expired breath samples from all patients and healt hy volunteers showed significantly greater (CO2)-C-14 specific activit y after omeprazole treatment (20 mg/day) than before treatment. Bacter ial overgrowth was found in the jejunal fluid and gastric juice of bat h. ulcer patients and healthy volunteers after omeprazole treatment. T he following species were identified: Escherichia coli, Candida albica ns, enterococcus, Lactobacillus bifidus, Bacteroides vulgatus, B unifo rmis, Eubacterium lentum, Eu parvum, and Corynebacterium granulosum. A ll of these species, except E coli and C albicans, deconjugate bile ac ids. There was a significant correlation between (CO2)-C-14 activity a nd gastric pH, both before and after omeprazole treatment in both grou ps. The triolein breath test revealed impaired fat absorption in both groups after omeprazole treatment. Conclusions-Both patients with gast ric ulcer and healthy volunteers exhibited increased deconjugation of bile acids caused by bacterial overgrowth in the jejunum and fat malab sorption after omeprazole treatment. The bacterial overgrowth consiste d of both anaerobes and aerobes with deconjugation ability and was pro bably associated with an omeprazole induced shift to neutral pH in the gastric juice.