Histological changes of gastric mucosa after Helicobacter pylori eradication: a systematic review and meta-analysis.

AIM: To systematically review pathological changes of gastric mucosa in gastric atrophy (GA) and intestinal metaplasia (IM) after Helicobacter pylori (H. pylori) eradication. METHODS: A systematic search was made of PubMed, Web of Science, EMBASE, ClinicalTrials.gov, OVID and the Cochran Library databases for articles published before March 2013 pertaining to H. pylori and gastric premalignant lesions. Relevant outcomes from articles included in the meta-analysis were combined using Review Manager 5.2 software. A Begg’s test was applied to test for publication bias using STATA 11 software. χ2 and I2 analyses were used to assess heterogeneity. Analysis of data with no heterogeneity (P > 0.1, I2 < 25%) was carried out with a fixed effects model, otherwise the causes of heterogeneity were first analyzed and then a random effects model was applied. RESULTS: The results of the meta-analysis showed that the pooled weighted mean difference (WMD) with 95%CI was 0.23 (0.18-0.29) between eradication and non-eradication of H. pylori infection in antral IM with a significant overall effect (Z = 8.19; P <0.00001) and no significant heterogeneity (χ2 = 27.54, I2 = 16%). The pooled WMD with 95%CI was -0.01 (-0.04-0.02) for IM in the corpus with no overall effect (Z = 0.66) or heterogeneity (χ2 = 14.87, I2 =0%) (fixed effects model). In antral GA, the pooled WMD with 95% CI was 0.25 (0.15-0.35) with a significant overall effect (Z = 4.78; P < 0.00001) and significant heterogeneity (χ2 = 86.12, I2 = 71%; P < 0.00001). The pooled WMD with 95% CI for GA of the corpus was 0.14 (0.04-0.24) with a significant overall effect (Z = 2.67; P = 0.008) and significant heterogeneity (χ2 = 44.79, I2 = 62%; P = 0.0003) (random effects model). CONCLUSION: H. pylori eradication strongly correlates with improvement in IM in the antrum and GA in the corpus and antrum of the stomach.