Health Questions and Answers

Question: Where in the gastrointestinal (GI) tract does Helicobacter pylori live?


The organism lives within or beneath the gastric mucous layer, somewhat protected from stomach acid. H. pylori has potent urease activity, which hydrolyzes urea to ammonia and bicarbonate and increases its resistance to the stomach’s low pH environment. H. pylori recognizes and binds to specific receptors expressed by gastric epithelial cells and, therefore, is able to adhere tightly to the epithelial cell surface. This attachment process may morphologically or functionally alter the epithelial cell. The organism has been found adherent to ectopic gastric epithelium throughout the GI tract, that is, esophagus (Barrett’s), duodenum (gastric metaplasia), small intestine (Meckel’s diverticulum), and rectum (ectopic patches of gastric mucosa).


  • McColl L, El-Omar E, Gillen D: Helicobacter pylori gastritis and gastric physiology. Gastroenterol Clin North Am 29:687-703, 2000.

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