[Bacterial colonization of the stomach caused by acid neutralization and inhibition of stomach emptying].

Gastric bacterial overgrowth was studied in 8 healthy volunteers. Total bacterial counts, nitrate-reducing bacteria and nitrite concentration were determined in fasting gastric juice before and after 4 weeks of treatment with a strong or with a mild antacid drug, a placebo preparation and the spasmolytic agent papaverine which is known to inhibit gastric evacuation. Placebo therapy and the mild antacid did not change any of the above parameters studied. The strong antacid caused a significant increase in the pH of gastric contents which was accompanied by an enormous increase in total bacterial counts, nitrate-reducing bacteria and nitrite concentration. Papaverine which did not cause a significant elevation of pH also definitely increased bacterial counts and nitrite concentration of gastric juice. Four weeks following termination of each treatment procedure, however, all changes outlined above had returned to pretreatment values. These results indicate that reversible gastric bacterial overgrowth under therapeutical conditions may occur when acidity of the stomach is reduced or gastric evacuation is retarded.