H. pylori infection, both in man and in the laboratory animal, has become a standard model to investigate fundamental problems in biology, such as microbial-host interactions, intracellular signalling, modulation of inflammation, mucosal atrophic metaplasia, and microbial resistance, to name just a few. The issues addressed in this book are grouped according to their leading theme. Topics include: the new Helicobacters, strain differences of H. pylori and their consequence on microbial-host interactions and the effects of H. pylori infection on the gastric mucosa. The role of H. pylori is explained in relation to: gastric carcinogenesis; gastroesophageal reflux disease; dyspepsia and long-term acid suppression. Eradication therapies are reviewed