Helicobacter pylori and allergy: Update of research

Core Tip

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.