Helicobacter pylori, which persistently colonizes the stomachs of ~50% of the world's human population, is the main risk factor for peptic ulceration (Chap. 287) as well as for gastric adenocarcinoma and gastric MALT (mucosa-associated lymphoid tissue) lymphoma (Chap. 87). Treatment for H. pylori has revolutionized the management of peptic ulcer disease, providing a permanent cure in many cases. The prevention of H. pylori colonization could potentially represent primary prevention of gastric malignancy and peptic ulceration. However, controversial but increasing evidence indicates that H. pylori may in fact offer some protection against recently emergent diseases—most notably gastroesophageal reflux disease (GERD).
