Where Does H. pylori Go in Microscopic Colitis? Lower Helicobacter pylori Infection and Risk of Microscopic Colitis: A Meta-Analysis

Introduction: The prevalence of helicobacter pylori (H. pylori)-negative gastritis is rare in the general population, but it was reported to be as high as 30% or 70% of patients with ulcerative colitis or Crohn's disease, respectively. Recently, it was reported that H. pylori was found significantly less common in celiac disease, inflammatory bowel disease, eosinophilic esophagitis patients. However, observational studies inconsistently reported the relationship between H. pylori infection and risk of microscopic colitis, with case series reported resolution of collagenous colitis after treatment for H. pylori. This systematic review and meta-analysis was conducted to explore their association. Methods: Potentially relevant studies were carried out through a search of Pubmed, medline and bibliographic secondary sources to identify all eligible articles through June of 2016. The search terms include but not limited to: “microscopic colitis”, “collagenous colitis” “lymphocytic colitis”, and “helicobacter pylori”. Results: The initial composite search identified 31 studies. From 4 studies selected for this study (3 studies were published studies, 1 author's unpublished study on microscopic colitis patients), a total of 3202 patients with microscopic colitis were included in the pooled study. Endoscopically biopsied tissue was used to detect the H. pylori in all studies. Overall meta-analysis favor a significant inverse association between Helicobacter pylori infection and microscopic colitis (cumulative OR 0.64, 95% CI 0.56 to 0.74, P < 0.0001). The pooled prevalence of stomach H. pylori infection in microscopic colitis patients was 6.5%. There was significant heterogeneity among studies and obvious publication bias. In USA study, patient age mean 61.8 ±14.8 years. Female: male: 3.6:1. There were significant inverse association between Helicobacter pylori gastritis and microscopic Colitis (OR 0.61. 95% CI: 0.52-0.70.) Conclusion: Although this study support possible inverse association between Helicobacter pylori infection and microscopic colitis. There is insufficient evidence to conclude any relationship between H. pylori infection and risk of microscopic colitis. Future prospective studies of H. pylori infection and this unique type of colitis with unknown etiology are needed. It is likely to be H. pylori negative, ab initio or after antibiotic treatment seem to be a risk factor for the onset of microscopic colitis.