Helicobacter pylori and Other Gastric Helicobacter Species

Helicobacter pylori is a motile, curved gram-negative rod that lives within the mucus layer overlying gastric epithelium in about half of the human population. Essentially all persons colonized with H. pylori have an inflammatory infiltrate in the gastric lamina propria. H. pylori typically does not cause any adverse effects, but its presence is associated with an increased risk of peptic ulcer disease and noncardia gastric adenocarcinoma. H. pylori may also confer health benefits, including a decreased risk of esophageal reflux and its consequences and protection against childhood asthma and related disorders. With the development of effective therapies to eradicate H. pylori, physicians are faced with the challenge of determining which patients will benefit from therapy and which may be harmed.