ALTERATIONS IN GASTRIC PHYSIOLOGY IN HELICOBACTER-PYLORI INFECTION - CAUSES OF DIFFERENT DISEASES OR ALL EPIPHENOMENA

Helicobacter pylori infection exerts variable effects on gastric acid secretion. It may increase acid secretion, decrease acid secretion or produce no overall change. The effect of the infection on acid secreti on depends upon the relative extent to which the Helicobacter pylori g astritis affects the antral and body mucosa of the stomach. When there is antral predominant, body-sparing gastritis, there is increased gas trin release and this is accompanied by increased acid secretion. When there is a significant body gastritis, acid secretion is reduced and subjects may be completely achlorhydric. The majority of subjects have both antral gastritis and body gastritis and this results in no overa ll change in gastric acid secretion. There is now increasing evidence that the alteration which Helicobacter pylori infection exerts upon ga stric acid secretion is a pivotal factor in determining the clinical o utcome of the infection. Subjects in whom the infection produces acid hypersecretion develop duodenal ulcer disease due to the increased duo denal acid load. In subjects in whom the infection induces marked hypo chlorhydria, there is an increased risk of gastric cancer The hypochlo rhydria probably plays an important role in the carcinogenic process a s high intragastric pH markedly mises intragastric nitrite levels, pro foundly lowers gastric juice ascorbic acid and allows colonization by nitrosating bacteria. The reason for the different functional response s to Helicobacter pylori infection is unclear but may be related to th e host's pre-morbid acid secretory status.