Helicobacter pylori and Respiratory Diseases: 2021 Update.

Marilena Durazzo,Giorgio Maria Saracco,Sharmila Fagoonee,Rinaldo Pellicano,Alessandro Adriani

doi:10.3390/microorganisms9102033

Abstract

Helicobacter pylori (H. pylori) is a Gram-negative bacterium involved in the development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue. Unexplained iron deficiency anemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency have also been related to H. pylori infection, whereas for other extra-gastric diseases, the debate is still open. In this review, we evaluate and discuss the potential involvement of H. pylori infection in the pathogenesis of several respiratory diseases. A MEDLINE search of all studies published in English from 1965 to 2021 was carried out. Controversial findings have been reported in patients with bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, lung cancer, tuberculosis, cystic fibrosis, and sarcoidosis. Most of the available literature is concerned with case-control studies based on seroprevalence, with a small sample size and low consideration of confounders, which represents a potential issue. So far, there is no clear evidence of a causal association between H. pylori infection and respiratory diseases, and larger studies with appropriate epidemiological design are required.

Highlights

Helicobacter pylori (H. pylori) infection is globally widespread, usually acquired during childhood, and often related to low socio-economic class [1]
It is well known that H. pylori infection may lead to gastritis, peptic ulcer disease (PUD), gastric adenocarcinoma and gastric mucosaassociated lymphoid tissue (MALT) lymphoma [5], most infected subjects remain asymptomatic
The authors associated the reduction of H. pylori prevalence with the rise in asthma cases as well as other allergic disorders in children, assuming a possible relationship [16]

Summary

Introduction

Helicobacter pylori (H. pylori) infection is globally widespread, usually acquired during childhood, and often related to low socio-economic class [1]. The precise mode of transmission remains unproven, it has been shown that such a microorganism spreads directly from one person to another, mainly by fecal-oral or oral-oral routes [2] This microaerophilic, Gram-negative bacterium is usually located within the mucus layer of the stomach, and certain ultrastructural details found on its surface (sheathed flagella and urease) are involved in its ability to survive in the surrounding hostile environment [3]. This disproves the ancient conception of the impossibility for microorganisms to survive in the gastric compartment due to acidity [4]. Only unexplained iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B12 deficiency have been associated with the latter infection, as reported in the fifth edition of the Maastricht/Florence

Results

Discussion

Conclusion