Helicobacter pylori infection and inflammatory bowel disease: Is there a link?

Abstract

Helicobacter pylori (H. pylori) infection is one of the most widely spread infectious diseases in humans. It can cause chronic gastritis, peptic ulcer disease and gastric malignancies and has been associated with extra-gastric disorders. H. pylori elicit a chronic systemic inflammatory response which, under certain conditions, may trigger autoimmune reactions and may be implicated in the pathogenesis of autoimmune diseases. Although the pathogenesis of inflammatory bowel disease (IBD) is unknown, it is thought to result from complex interactions between environmental factors and microbiota in the gut of individuals who are genetically susceptible. Several bacterial and viral agents have been implicated in the aetiology of IBD. In theory, H. pylori infection could be involved in the pathogenesis of IBD by inducing alterations in gastric and/or intestinal permeability or by causing immunological derangements resulting in absorption of antigenic material and autoimmunity via various immunological pathways. Similar mechanisms may also be responsible for the co-existence of IBD with other autoimmune diseases and/or extra-intestinal manifestations. However, the epidemiological data fail to support this association. In fact, various studies indicate that the prevalence of H. pylori infection is low in patients with IBD, suggesting a protective role for this infection in the development of IBD. In this report, we aim to shed light on proposed mechanisms and confounding factors underlying the potential link between H. pylori infection and IBD.

Keywords: Helicobacter pylori; Inflammatory bowel disease; Ulcerative colitis; Crohn’s disease; Colorectal cancer

Core tip: By gathering a large volume of published data, this review attempts to shed light on the mechanisms and confounding factors underlying the potential link between Helicobacter pylori (H. pylori) infection and Inflammatory Bowel Disease (IBD). However, whether the link between H. pylori and IBD is coincidental, epiphenomenal or mechanistic remains to be elucidated as there are contradictory data regarding both the causative and the protective role of H. pylori infection against IBD. This review provides a tool for researchers in this field to use as they perform further research to find the missing links.