Effects of dietary calcium on Helicobacter pylori-induced gastritis in Mongolian gerbils

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. 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. '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. Intake of calcium compounds may contribute to enhancement of Hp-induced gastritis.