BACKGROUND AND AIMS To date, data on the effects of anti-Helicobacter therapy on the improvement of atrophic gastritis (AG) and intestinal metaplasia (IM) have been conflicting. This study was performed to investigate whether eradication of H. pylori could lead to the improvement of AG and IM, and the prognostic factors associated with the improvement of AG and IM.

METHODS Four hundred patients consisting of H. pylori-negative (n = 116) and H. pylori-positive (n = 284) groups were followed up 1 and 3 years after initial H. pylori tests. Serum levels of pepsinogen (PG), bacteria, environmental factors, and genetic polymorphisms were determined.

RESULTS The grade of corpus atrophy decreased at 1 and 3 years after successful eradication (p < .001 and p = .033, respectively). However, there was no significant change in the IM in the antrum and in the corpus. Prediction factors for the improvement of corpus AG by H. pylori eradication were baseline low PG I/II ratio (≤3), high salt intake, and corpus-predominant gastritis. IM improvement was also associated with spicy food intake and high baseline grade of IM, in addition to these factors. In addition, IL-1B-511 C/T and IL-6-572 C/G alleles were found to inhibit IM improvement. However, H. pylori-negative and noneradicated group did not show any significant change in AG or IM.

CONCLUSION Corpus AG was reversed by H. pylori eradication, and improvement of IM by H. pylori eradiation was more definite in patients with severe IM, low PG I/II ratio, and corpus-predominant gastritis, suggesting that H. pylori eradication is valuable even in severe cases.