Effects of Dietary Calcium on Helicobacter pylori-induced Gastritis in Mongolian Gerbils

Background and Aims: Helicobacter pylori (Hp) infection causes gastritis and is considered a gastric cancer risk factor. We have previously reported that codfish meal markedly enhanced Hp-induced gastritis in Mongolian gerbils. In the present study, we sought the responsible components in codfish meal. Materials and Methods: Codfish were divided into three parts (meat, viscera and 'other parts', including bone), and administered to Hp-infected gerbils. Subsequently, cod bone, sardine bone and prawn shell were tested, along with major calcium components, hydroxyapatite and calcium carbonate, in bone and shell, respectively. Results: 'Other parts' and cod bone enhanced Hp-induced gastritis, as was observed for whole codfish. Similarly, sardine bone and prawn shell, as well as 0.22-0.88% hydroxyapatite and calcium carbonate, enhanced gastritis. In contrast, administration of a higher dose of the calcium compounds exerted protective effects. Conclusion: Intake of calcium compounds may contribute to enhancement of Hp-induced gastritis.