Ethanol intake preceding Helicobacter pylori inoculation promotes gastric mucosal inflammation in Mongolian gerbils

BACKGROUND: Mongolian gerbils have been reported to be a suitable model for Helicobacter pylori-associated gastric mucosal injury, including gastric cancer. Although ethanol is known to be one of the harmful substances in the gastric mucosa, the relationship between ethanol and H. pylori infection remains unknown. The aim of the present study is to investigate the effect of ethanol treatment prior to H. pylori inoculation on associated gastric mucosal injury. METHODS: Male Mongolian gerbils were used for the study. Helicobacter pylori was orally inoculated after 15 h fasting (Hp group). Thirty minutes prior to H. pylori inoculation, a group of gerbils was orally treated with 40% ethanol (20 mL/kg; E + Hp group). Another group of animals was treated either with H. pylori culture media alone (controls) or with 40% ethanol plus culture media (E group). Gerbils were killed 2, 4 or 12 weeks after H. pylori inoculation. Helicobacter pylori infection was confirmed by both histological examination and serological tests. Mucosal damage was evaluated histologically according to the modified Sydney system. RESULTS: Although in the controls and E group no significant change to the gastric mucose was observed, persistent H. pylori infection was seen in the mucosa and mucosal leucocyte infiltration and severe epithelial damage was observed in the Hp and E + Hp groups after 4 weeks. The histological scores for polymorphonuclear cell infiltration and myeloperoxidase activity were higher in the E + Hp group at 4 weeks than in the Hp group (P < 0.05). CONCLUSIONS: Ethanol intake preceding H. pylori inoculation could promote the progression of gastric mucosal inflammation in Mongolian gerbils.