Alteration of histological gastritis after cure of Helicobacter pylori infection

Background: It is still disputed whether gastric atrophy or intestinal metaplasia improves after the cure of Helicobacter pylori infection. Aim: To clarify the histological changes after the cure of H. pylori infection through a literature survey. Methods: Fifty-one selected reports from 1066 relevant articles were reviewed. The extracted data were pooled according to histological parameters of gastritis based on the (updated) Sydney system. Results: Activity improved more rapidly than inflammation. Eleven of 25 reports described significant improvement of atrophy. Atrophy was not improved in one of four studies with a large sample size (> 100 samples) and in two of five studies with a long follow-up period (> 12 months), suggesting that disagreement between the studies was not totally due to sample size or follow-up period. Methodological flaws, such as patient selection, and statistical analysis based on the assumption that atrophy improves continuously and generally in all patients might be responsible for the inconsistent results. Five of 28 studies described significant improvement of intestinal metaplasia. Conclusions: Activity and inflammation were improved after the cure of H. pylori infection. Atrophy did not improve generally among all patients, but improved in certain patients. Improvement of intestinal metaplasia was difficult to analyse due to methodological problems including statistical power.