Suppression of gastric acid secretion in patients with gastroesophageal reflux disease results in gastric bacterial overgrowth and deconjugation of bile acids
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The aim of this study was to test the hypothesis that gastric bacterial overgrowth is a side effect of acid suppression therapy in patients with gastroesophageal reflux disease (GERD) and that the bacteria-contaminated gastric milieu is responsible for an increased amount of deconjugated bile acids. Thirty patients with GERD who were treated with 40 mg of omeprazole for at least 3 months and 10 patients with GERD who were off medication for at least 2 weeks were studied. At the time of upper endoscopy, 10 ml of gastric fluid was aspirated and analyzed for bacterial growth and bile acids. Bacterial over-growth was defined by the presence of more than 1000 bacteria/ml. Bile acids were quantified via high-performance liquid chromatography. Eleven of the 30 patients taking omeprazole had bacterial over-growth compared to one of the 10 control patients. The median pH in the bacteria-positive patients was 5.3 compared to 2.6 in those who were free of bacteria and 3.5 in the control patients who were off medication. Bacterial overgrowth only occurred when the pH was >3.8. The ratio of conjugated to unconjugated bile acids changed from 4:1 in the patients without bacterial overgrowth to 1:3 in those with bacterial growth greater than 1000/ml. Proton pump inhibitor therapy in patients with GERD results in a high prevalence of gastric bacterial overgrowth. The presence of bacterial overgrowth markedly increases the concentration of unconjugated bile acids. These findings may have implications in the pathophysiology of gastroesophageal mucosal injury.
Key wordsBacterial overgrowth omeprazole deconjugation
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- 7.Hill M. Normal and pathological microbial flora of the upper gastrointestinal tract. Scand J Gastroenterol (Suppl) 1985; 111:1–6.Google Scholar
- 15.Bergey DH. Bergey’s Manual of Determinative Bacteriology. Baltimore: Williams & Wilkins, 1994.Google Scholar
- 18.Kivilaasko E, Fromm D, Silen W. Effect of bile acids and re- lated compounds on isolated esuphageal mucosa. Surgery 1989;87:280–285.Google Scholar
- 22.Theisen J, Danenberg K, DeMeester TR, et al.. Effect of acid and bile salts on COX-2 gene expression on an esophageal adenocarcinoma cell line [abstr]. Proc Am Assoc Cancer Res 1999;40:505.Google Scholar