Helicobacter pylori in Human Oral Cavity and Stomach

Helicobacter pylori is the primary cause for gastritis, peptic ulcers and may also be responsible for gastric cancer. Ample evidence has accumulated from recent studies, suggesting that H. pylori may also be present in the human oral cavity. There is, however, disagreement about the frequency of occurrence of this bacterium in the oral environment and the relation to a colonization of the stomach. Objective: in the present clinical study, it was investigated whether there is a coincidence of occurrence of H. pylori in the oral cavity with an infection of the stomach by this bacterium. Methods: Samples from four different areas of the oral cavity (interdental, sub-gingival, tongue, saliva), two gastric biopsies (corpus, antrum), and serum were collected from 94 gastric patients. The identification of H. pylori was performed by nested light cycler real-time PCR and by conventional nested PCR with two different pairs of primers. All positive PCR-products were further proven by DNA-sequencing. Results: H. pylori was identified in the oral cavity of 16 (17%) and in the stomach of 29 (31%) patients. 40 patients (43%) were serum-positive. In the oral cavity, no particular area stood out that was preferentially colonized. In only 6 of the 29 patients that were colonized in the stomach, the bacterium was also found in the oral cavity (in 4 cases recovered from the tongue, in one case from saliva, in one case from sub-gingival plaque). Only in 5 of the 40 serum-positive patients H. pylori was found also in the oral cavity. These 5 patients were also colonized in the stomach. Conclusion: In summary, these findings do not support the theory that the occurrence of H. pylori in the oral cavity depends on a colonization of the stomach. This study was supported from the DFG (SFB-585, Project B5).