Helicobacter pylori in Japan.

Recent international consensus statements have concluded that Helicobacter pylori is a causal factor in peptic ulcer disease and a Group 1 carcinogen in humans, and that all patients with peptic ulcer associated with H. pylori infection should receive eradication therapy. There are marked differences in the presentation of peptic ulcer disease between Japanese patients and those from other countries, however, and thus a committee of the Japanese Society of Gastroenterology has been set up to develop guidelines for clinical trials in patients with gastric or duodenal ulcers associated with H. pylori. According to these guidelines, eradication therapy should normally consist of dual therapy with a proton pump inhibitor, such as omeprazole, and an antibiotic; a nitroimidazole can be added, however, if necessary. The diagnosis of H. pylori should be made on the basis of a positive culture of the organism or histological examination of gastric biopsies, together with a positive urease test or 13C-urea breath test. Eradication should be confirmed by the same means 4-6 weeks after treatment. Other research is investigating the relationship between H. pylori and gastric cancer, an important issue in view of the high incidence of this condition in Japan. There is evidence that the Mongolian gerbil may be a useful animal model to investigate this question.