Helicobacter pylori and respiratory diseases: Update for pneumologist

Helicobacter pylori (H. pylori) infection is one of the main causes of gastric diseases; moreover, it has been associated to the pathogenesis of some extradigestive disorders, including those of the respiratory system. Non conclusive findings of H. pylori direct involvement have been found in patients with obstructive diseases like asthma and chronic obstructive disease, lung cancer, pulmonary tuberculosis infection, cystic fibrosis, bronchiectasis and interstitial lung diseases. Scientific evidences are limited to case-control studies and some meta-analysis but, up to now, there is not a clear and definite evidence of a causal relationship between H. pylori infection and development of respiratory diseases. In this narrative review we have analyzed the possible role and the underlying mechanisms of H. pylori infection in development of respiratory diseases, reporting the main results of the principal studies published on the matter.