Background: Recent reports have indicated that Helicobacter pylori (H. pylori) might have an effect on gastrointestinal flora; moreover, gastric commensual bacteria have been observed in the development of duodenal ulcer (DU). Aims: In our study, we aimed to evaluate the effect of H. pylori eradication on gastrointestinal flora in DU patients.

Methods: A case-control study was performed at Jiangsu Shengze Hospital between December, 2013 and April, 2014. The patients received antibiotic eradication therapy if H. pylori testing was positive. At least four weeks after cessation of the eradication therapy, a repeat gastroscopy was performed to collect biopsies again in the same position. Gastric mucosa samples and feces specimens were collected to extract bacteria DNA and then to quantify by real-time polymerase chain reaction (PCR).

Results: After the eradication of H. pylori, an increase of Lactobacillus group, Clostridium leptum subgroup, Enterobacteria and a decrease of Clostridium coccoides subgroup were found in the antrum. In the corpus, the number of bacteria in the Lactobacillus group was increased and the expression of Clostridium coccoides subgroup was significantly down-regulated. In the feces samples, only the number in the Lactobacillus group was increased. Moreover, the distribution was significantly different between female and the male patients.

Conclusions: The presence of H. pylori in the stomach suppressed the colonization with Lactobacillus group, Clostridium leptum subgroup and Enterobacteria. Gender might affect the distribution and/or recolonization of the bacteria in DU patients.

Abbreviations: DU: duodenal ulcer; GI: gastrointestinal; GIN: gastrointestinal neoplasia; GU: gastric ulcer; PPI: proton pump inhibitors; UBT: urea breath test.


gastrointestinal micro-ecology, Helicobacter pylori, Duodenal ulcer, Lactobacillus