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

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 a-he 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 farming 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) mu m, 106 (30) pm respectively). There was however a significant reduction in mucus thickness in those H pylori positive subjects with underlying gastric atrophy (84 (13) Pm, 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.