Microflora of gastric biopsies from patients with duodenal ulcer and gastric cancer: a comparative study of patients from Korea, Colombia, and the United States.

It remains unclear why the spectrum of H. pylori-related diseases differs among different geographic regions. We examined the non-H. pylori contamination rates of the stomach in patients with duodenal ulcer or gastric adenocarcinoma from three different regions with different spectra of H. pylori-related diseases. Gastric biopsies were cultured from patients with duodenal ulcer or histologically proven gastric cancer from Seoul, Korea; Bogota, Colombia; and Houston, Texas. The frequency of non-H. pylori contamination was tallied in relation to the clinical diagnosis. Cultures from 247 duodenal ulcer patients and 165 patients with gastric cancer had bacterial growth. H. pylori was isolated from 207 (73.7%) patients with duodenal ulcer and 90 (47.1%) patients with gastric cancer (P < 0.001). In patients with duodenal ulcer (DU) or gastric cancer (GC), the rate of positive cultures for H. pylori were not statistically different (P > 0.143 for DU, P > 0.190 for GC) between regions. The frequency of isolation ranged from 69% to 79% for DU patients and from 39% to 50% for gastric cancer patients. Non-H. pylori bacterial contamination was found more frequently (63%) in Colombian duodenal ulcer patients compared to 30% ulcer patients from the United States or Korea (P < 0.001). Non-H. pylori growth occurred in 50.8-75.5% of cancer patients and was significantly lower in US patients than in patients from either Colombia or Korea (P < 0.01). The geographic location as well as disease status affects the rate of H. pylori recovery and non-H. pylori contamination of the stomach and may play a role in the geographic differences in manifestation of H. pylori infection. The fact that the proportion of gastric cancer patients in the United States with non-H. pylori contamination was significantly less than that of Korea or Colombia shows that the notion of an almost universal increase in gastric microbial content in gastric adenocarcinoma should be reconsidered.