Marked enhancement by fish meal of Helicobacter pylori-induced gastritis in Mongolian gerbils

In a search for dietary factors influencing Helicobacter pylori-induced gas tritis, the effects of fish meal in the diet were examined in Mongolian ger bils, When a conventional diet containing 10% fish meal was given to Mongol ian gerbils for 4 weeks after inoculation of H. pylori, edematous thickenin g with severe neutrophil and mononuclear cell infiltration in both the muco sa and submucosa was observed in the glandular stomach of 19 out of the 20 animals, and hemorrhagic spots were evident in 11 cases. These gastric lesi ons were enhanced by a 20% fish meal supplement, and edema and hemorrhage i n the gastric mucosa were observed in 19 and 17 out of 20 animals, respecti vely. Although almost the same levels of viable bacteria were detected inde pendent of the diet, edema and hemorrhage were seen In only 2 and 1 of 20 g erbils fed a diet containing 10% casein, instead of 10% fish meal, respecti vely, Neither edema nor hemorrhage was observed in 10% beef diet animals. T hese results suggest that fish meal contains factors which greatly enhance H. pylori-induced gastritis in Mongolian gerbils, Since the incidences of g astritis and gastric cancer are very high throughout the world, it is very important to identify these gastritis-enhancing factors.