Correlations Among Gastric Juice pH and Ammonia, Helicobacter Pylori Infection and Gastric Mucosal Histology

BACKGROUND To assess the relationships among gastric pH and ammonia level, H. pylori infection, and gastric mucosal histology, we determined the gastric juice pH and ammonia concentration in H. pylori gastritis. METHODS The pH levels and ammonia concentrations were determined in gastric juice collected from 143 patients with dyspepsia during an endoscopy and compared according to a H. pylori infection. We also looked for correlations between two chemical parameters, between each of these parameters and H. pylori density, and histology. RESULTS Gastric pH levels and ammonia concentrations were higher in 94 infected patients than in the uninfected (3.16 vs. 1.55, p = 0.0001; 5.58 +/- 2.69 vs. 2.00 +/- 1.49 mol/L, p = 0.0001). Among 28 patients who received eradication therapy, 19 (67.9%) were successful, and their gastric pH levels and ammonia concentrations were significantly lower than those in the eradication failure group (1.60 vs. 2.33, p = 0.007; 1.77 +/- 1.28 vs. 4.02 +/- 1.20 micromoL/L, p = 0.0001). Gastric pH was significantly associated with intragastric ammonia concentration (p = 0.025) and gastritis activity (p = 0.018). Gastric pH and the ammonia level were significantly correlated with each other (rs = 0.495, p < 0.01), and with H. pylori density (rs = 0.467; rs = 0.735, p < 0.01), gastritis severity (rs = 0.343; rs = 0.478, p < 0.01), and gastritis activity (rs=0.418; rs = 0.579, p < 0.01). CONCLUSION Gastric juice pH and ammonia concentration reflect well the status of a H. pylori infection, and significantly correlate with each other and with H. pylori density, gastritis severity and activity. These findings suggest that intragastric ammonia produced by H. pylori may have a partial role in an increased gastric juice pH, and has a pathogenic role in H. pylori gastritis.