Epidemiological study for association between Helicobacter infection and gastrointestinal diseases

本研究探讨了幽门螺杆菌（H. pylori和H. suis）和胃肠道疾病。H.幽门螺杆菌是人类I类致癌物。CagA是H. pylori与胃癌相关。东亚CagA在胃癌患者中的患病率显著高于慢性胃炎患者。东亚CagA阳性H。幽门感染因此，携带东亚CagA阳性H.幽门螺杆菌感染者比感染西方CagA阳性菌株的人患胃癌的风险更高。H. suis与H.幽门螺杆菌，在各种动物的胃中发现，包括猫、狗和猪，以及人类。H.猪感染引起胃粘膜相关淋巴组织（MALT）淋巴瘤。H.幽门感染与此相反，在H.猪感染。

In this study, we investigated the relationship between Helicobacterinfection (H. pylori and H. suis) and gastrointestinal diseases in Asian and African countries. H. pyloriis a group I carcinogen in human. CagA is a most important virulent factor of H. pyloriassociate with gastric cancer. The prevalence of East Asian CagA was significantly higher in patients with gastric cancer than in patients with chronic gastritis. The much greater magnitude of risk observed with East Asian CagA-positive H. pyloriinfection. Therefore, patients harboring East Asian CagA-positive H. pylori are at a higher risk for developing gastric cancer than those infected with Western CagA-positive strains. H. suis, which belongs to the Helicobacterfamily just like H. pylori, was found in the stomachs of various animals including cats, dogs and pigs, and furthermore humans. H. suis infection caused gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Th1 host response was predominant in H. pyloriinfection. In contrast, both Th1 and Th2 host response were up-regulated in H. suisinfection.