[Gastroduodenal ulcer before and after Helicobacter pylori].

Before the discovery of Helicobacter pylori, ulcer disease was considered as the result of a conflict between gastric acid and pepsin, on one side, and protection afforded by gastric mucosal barrier, on the other side. The discovery of H. pylori by Marshall and Warren in 1982 overthrew this conception and revealed ulcer disease mainly as an infectious disease. H. pylori eradication with an appropriate triple therapy is now considered as the gold standard treatment of gastroduodenal ulcer. The pathogenic role of H. pylori lies far beyond ulcer disease since H. pylori is looked as involved in nonulcer dyspepsia, nonsteroidal anti-inflammatory drug ulcers, gastric cancer, MALT lymphoma and, eventually, oesophageal adenocarcinoma, and nondigestive diseases as cardiovascular diseases. The pandemic nature of the H. pylori infection, particularly within developing countries, combined with emerging resistances to antibiotics make the development of a vaccine a public health necessity. The relationships between the human host and the bacterium remains mostly unknown, some of which could be beneficial.