Association of gastric hypoacidity with opportunistic enteric infections in patients with AIDS.

To determine the relation and possible significance of gastric hypoaciditity to chronic diarrhea in AIDS, patients with and without chronic (greater than 1 month) diarrhea underwent fasting gastric juice pH measurement and microbiologic study and upper and lower endoscopy with biopsy. All 8 patients with diarrhea and high gastric pH (greater than 3; mean, 6.1 +/- 1.0) had gastric bacterial overgrowth (greater than 10(4) bacteria/mL) along with opportunistic enteropathogens in the duodenum or rectosigmoid, but only 1 of 6 patients with diarrhea and gastric pH in the normal range (less than or equal to 3; mean, 1.9 +/- 0.7) had overgrowth or an opportunistic enteropathogen. By contrast, all but 1 of 9 controls (AIDS patients without diarrhea) had normal fasting gastric pH (mean, 2.9 +/- 1.5). Overall, the presence of gastric hypoacidity was associated with identification of opportunistic enteropathogens (P = .035). Thus, gastric hypoacidity is associated with quantitative bacterial overgrowth and opportunistic enteric infections and may be etiologically important in the pathophysiology of the chronic diarrhea seen in some AIDS patients.