Hp and pH: implications for the eradication of Helicobacter pylori

Helicobacter pylori infection causes inflammation of the gastric and duodenal mucosae, which results in a disturbance of the regulatory mechanisms for gastrin, gastric acid and pepsin secretion. Acid secretion may be decreased, normal or increased, depending on the stage of infection, although the meal-stimulated gastrin response is invariably elevated. The exact mechanisms involved are not known but may be due to the release of cytokines in response to bacterial toxins. H. pylori colonization is reduced by effective acid suppression with proton pump inhibitors, although it is not eradicated. In combination with amoxycillin, omeprazole, up to 40 mg twice daily, eradicated the organism in up to 82% of cases. This synergistic effect may be due to a direct effect of omeprazole on the organism, the protection of amoxycillin from acid degradation, or enhancement of host defence mechanisms accompanying acid suppression.