gram-negative_bacterial_infectious_disease obsolete Helicobacter pylori gastritis true A commensal Helicobacter infectious disease that involves inflammation of the stomach lining caused by Helicobacter pylori, which contributes to ulcer formation by increasing acid production, interfering with the normal defenses against stomach acid, and producing toxins. The symptoms include indigestion and pain or discomfort in the upper abdomen. DOID:4036 Helicobacter gastritis disease_ontology Helicobacter-associated gastritis (disorder)