Published online Dec 26, 2015. doi: 10.5662/wjm.v5.i4.203
Peer-review started: May 12, 2015
First decision: June 18, 2015
Revised: September 18, 2015
Accepted: October 16, 2015
Article in press: October 19, 2015
Published online: December 26, 2015
Processing time: 223 Days and 18.1 Hours
Recently a lot of literature has been published about the possible preventive action of Helicobacter pylori (H. pylori) against allergy. The present review summarizes research data about the association between H. pylori and allergic diseases, as well as discusses possible hypotheses about the preventive action of H. pylori against atopy. There is evidence from observational studies to support a weak inverse association between prevalence of H. pylori infection and allergy. However, confounders like some unidentified socioeconomic factors, antibiotic use and others could bias the association. Although data from cohort studies point to a possible association of H. pylori with some of the allergic diseases, no definite proof for causal relationship has been clearly demonstrated yet. A biological mechanism proposed to explain the preventive action of H. pylori to allergy is reduced exposure to a major stimulus for the generation of Treg cells in individuals without H. pylori infection. In addition, H. pylori could be an indicator for changes in gut microbiome, reflecting the complex interaction between microbes and immune system.
Core tip: Review summarizes research data about the association between Helicobacter pylori (H. pylori) and allergic diseases. Results from observational studies support a weak inverse association between prevalence of H. pylori and allergy. However, different confounders like unidentified socioeconomic factors, antibiotic use and others could bias the observed association. Further, no definite proof for causal relationship has been clearly demonstrated yet, although data from cohort studies point to a possible association of H. pylori with some of the allergic diseases. Finally, microbiological studies show that H. pylori could be an indicator for changes in gut microbiome during recent decades, reflecting the complex interaction between microbes and immune system.