Helicobacter pylori感染スナネズミにおける魚粉の胃炎促進作用

Epidemiological and laboratory animal studies have suggested a positive association between Helicobacter pylori infection and gastric carcinogenesis. In Japan, gastric cancer is the most common and leading cause of cancer death. This study was designed to investigate the effects of fish meal on H. pyloriinduced gastritis in Mongolian gerbils in order to find dietary factors associated with gastric carcinogenesis. Male 7 week-old Mongolian gerbils were inoculated with H. pylori (ATCC43504) 0.5 ml (0.5×10^9CFUs) by gavage and a dietary regimen maintained as follows for 4 weeks : 0% fish meal (casein instead of fish meal in conventional diet); 10% fish meal (conventional diet); 20% fish meal (conventional diet plus 10% fish meal). All animals were sacrificed at 4 weeks after inoculation with H. pylori. In all gerbils inoculated with H. pylori, about 10^5 viable bacteria were counted, without any significant intergroup differences. In macroscopic findings, gastric edema and hemorrhage were observed in 10 and 5, 95 and 55, and 95 and 85% of animals in the 0, 10, and 20% fish meal diet groups, respectively. Histopathological examinations indicated that a fish meal diet significantly increased activity and inflammation indices of the stomach in a dose-dependent manner. These results suggest that some dietary factors in a fish meal diet enhance H. pylori-induced gastritis and may be dietary factors which enhance gastric carcinogenesis.