It is well known that helicobacter pylori are the major cause of chronic gastritis world-wide. The association of helicobacter pylori infection included duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. Helicobacter pylori have been established as a risk factor for hastric adenocarcinom. Helicobacter eradication is associated with an increase in distal esophagitis and gastro-esophageal reflux disease.