Helicobacter pylori: friend or foe?

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium that is present in nearly half the world's population. It is the major cause of peptic ulcer disease and a recognized cause of gastric carcinoma. In addition, it is linked to non-ulcer dyspepsia, vitamin B12 deficiency, iron-deficient anemia and immune thrombocytopenic purpura. These conditions are indications for testing and treatment according to current guidelines. An additional indication according to the guidelines is "anyone with a fear of gastric cancer" which results in nearly every infected person being eligible for eradication treatment. There may be beneficial effects of H. pylori in humans, including protection from gastroesophageal reflux disease and esophageal adenocarcinoma. In addition, universal treatment will be extremely expensive (more than $32 billion in the United States), may expose the patients to adverse effects such as anaphylaxis and Clostridium difficile infection, as well as contributing to antibiotic resistance. There may also be an as yet uncertain effect on the fecal microbiome. There is a need for robust clinical data to assist in decision-making regarding treatment of H. pylori infection.