[Helicobacter pylori as a new paradigm in the pathogenesis of upper GI diseases].

Discovery of H. pylori from human gastric mucosa have induced an evolution in the concepts of upper GI diseases, especially in those of gastritis, peptic ulcer and gastric cancer. A new classification of gastritis, Sydney system and updated Sydney system, are proposed and commonly used in worldwide. Eradication treatment against H. pylori infection can completely improve the histologic gastritis, which is defined by the infiltration of inflammatory cells. In gastric and duodenal ulceration, the eradication of H. pylori accelerates the ulcer healing without acid suppression, and prevents the ulcer recurrence without any maintenance therapy. These accumulating data suggest that H. pylori could have an etiologic relation to ulcer diseases, because these are a kind of intervention study on etiology. Thus, in ulcer diseases, H. pylori is proven to play an etiologic role. On the basis of these studies, a new treatment strategy is proposed in upper GI diseases. This is a new paradigm on upper GI diseases.