The influence of Helicobacter pylori infection on postprandial duodenal acid load and duodenal bulb pH in humans.

BACKGROUND & AIMS: Recently, we postulated a new concept of duodenal ulcer pathogenesis suggesting that antral Helicobacter pylori infection blocks inhibitory pathways to the gastrin and parietal cells, resulting in an increased and prolonged postprandial acid secretion. the aim of this study was to examine duodenal acid load and duodenal bulb pH after a meal before and after eradication of H. pylori.

METHODS

Using a marker-dilution method and a pH electrode in the duodenal bulb, gastric emptying, acid secretion, gastrin release, duodenal acid load, and duodenal bulb pH were studied during 2 hours after peptone meals of pH 7.0 and 2.0 in 8 H. pylori-negative controls and 8 H. pylori-infected subjects before and 6 months after eradication.

RESULTS

The H. pylori-infected subjects had an increased gastric emptying, gastrin release, and acid secretion, higher duodenal acid load, and lower duodenal bulb pH after the meals. These responses were normalized after eradication.

CONCLUSIONS

H. pylori-infected subjects have an increased and prolonged postprandial acid secretion, partly caused by an impaired low pH inhibition of acid secretion, gastrin release, and gastric emptying, resulting in an increased duodenal acid load and a prolongation of low pH in the duodenal bulb, as a general prerequisite for the development of duodenal ulcer disease.