Objective: MUC1, a membrane-bound mucin, is one of the important components of the gastric mucus unstirred layer, protecting the mucosa from the enzymatic attack of acid and pepsin, as well as from toxins and microorganisms. The aim of the study is to investigate the relationship between H. pylori and MUC1 expression in gastric mucosa.

Materials and Methods: English Medical literature searches were conducted for gastric MUC1 expression in H. pylori-infected patients vs. uninfected people. Searches were performed up to August 31, 2023, using PubMed, EMBASE, Scopus, and CENTRAL. Meta-analysis was performed by using Comprehensive meta-analysis software (Version 4, Biostat Inc., Englewood, NJ, USA). Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Heterogeneity was evaluated using Cochran Q-test, and it was considered to be present if the Q-test p-value was less than 0.10. I2 statistic was used to measure the proportion of inconsistency in individual studies, with I2 > 50% representing heterogeneity. We also calculated a potential publication bias.

Results: 6 studies, which represent 9 sub-studies, were selected according to the inclusion criteria. The odds ratio of MUC1 expression in random effect analysis was 0.625, 95% CI 0.178-2.196, 37.5% lower in H. pylori gastritis than in normal mucosa. Heterogeneity and inconsistency were moderate, and no publication bias was demonstrated.

Conclusions: This meta-analysis showed that MUC1 expression is lower in H. pylori infected mucosa, which may have a significant effect on the survival of the bacterium and persistent chronic mucosal inflammation.