Helicobacter pylori in vivo causes structural changes in the adherent gastric mucus layer but barrier thickness is not compromised

Abstract

Background - It has been proposed that a pathogenic effect of Helicobacter pylori is a weakening of the protective mucus barrier; however, this remains controversial. Aims - To clarify the effects of H pylori infection on the mucus gel barrier in vivo. Methods - Mucus gel polymeric structure and the thickness of the adherent mucus barrier were measured in endoscopic biopsy samples in subjects with and without H pylori infection. Results - There was a significant 18% reduction in the proportion of polymeric gel forming mucin in the adherent mucus layer in H pylori positive compared with negative subjects. There was no change in the adherent mucus thickness between H pylori positive and negative subjects without gastric atrophy (mean (SD): 104 (26) μm, 106 (30) μm respectively). There was however a significant reduction in mucus thickness in those H pylori positive subjects with underlying gastric atrophy (84 (13) μm, p=0.03) compared with those without atrophy. Conclusions - A partial breakdown in gel forming structure of the gastric mucus barrier does occur in H pylori infection per se but this is insufficient to cause a collapse of the mucus barrier.