Thus, to more fully define the gerbil gastric mucosal microbiota within the context of microbial and environmental risk factors for cancer, we investigated the roles of (i) CagA in gastric dysbiosis associated with H. pylori infection, (ii) dysbiosis associated with iron deficiency within the context of H. pylori infection, and (iii) dysbiosis associated with the severity of gastric lesions along the carcinogenesis cascade. The gene discussed is S100A8; the disease is cancer.