Helicobacter pylori in the oral cavity reflects handling of contaminants but not gastric infection

Helicobacter pylori colonises the gastric mucosa, but can also be found within the oral cavity. The presence of H. pylori was monitored in the oral cavity of 22 patients with duodenal ulcer, before and after antibiotic treatment and of 24 hospital employees who were or were not professionally exposed to H. pylori, Gastric infection was determined by breath test. Bacteria in the oral cavity were detected by nested PCR of samples containing saliva and dental plaque, using primers specific for 16S rRNA and ureC genes. Before treatment, 9 out of 22 infected ulcer patients harbored H. pylori in their oral cavity. Bacteria disappeared from the oral cavity of 3 of 7 cured patients. Twelve of 17 exposed subjects harbored H, pylori in their oral cavity, while no bacteria could be detected in the mouths of the 7 nonexposed subjects. Presence of bacteria in the oral cavity reflects handling of contaminants; it does not correlate with gastric infection and does not seem to promote it.