Microbiota in human alimentary tract plays important roles for homeostatic maintenance of the body. Compositional difference of gut microbiota is tightly associated with susceptibility of many diseases,including infla...Microbiota in human alimentary tract plays important roles for homeostatic maintenance of the body. Compositional difference of gut microbiota is tightly associated with susceptibility of many diseases,including inflammatory diseases,obesity,diabetes mellitus,cancer,and atherosclerosis. "Dysbiosis" refers to a state of imbalance among the colonies of microorganisms within the body,which brings abnormal increase of specific minor components and decrease in the normally dominant species. Since stomach secrets strong acid for its digestive role,this organ has long been thought a sterile organ. However,the discovery of Helicobacter pylori(H. pylori) has changed the concept. This bacterium has proven to cause gastritis,peptic ulcer,and gastric cancer. However,recent cross-sectional studies revealed that H. pylori carriers had a decreased risk of developing immunological diseases,such as asthma. H. pylori coinfection also suppresses inflammatory bowel diseases. This review describes human gastric microbiota by discussing its mutual interaction and pathogenic enrollment. Gastric "dysbiosis" may affect host inflammatory response and play important role for gastric pathogenesis. We will topically discuss enrollment of dysbiosis for genesis of gastric cancer as well as for disruption of immunological homeostasis affecting oncogenic resistance.展开更多
Epstein-Barr virus(EBV)-associated gastric cancer(EBVaGC)cells originate from a single-cell clone infected with EBV.However,more than 95%of patients with gastric cancer have a history of Helicobacter pylori(H.pylori)i...Epstein-Barr virus(EBV)-associated gastric cancer(EBVaGC)cells originate from a single-cell clone infected with EBV.However,more than 95%of patients with gastric cancer have a history of Helicobacter pylori(H.pylori)infection,and H.pylori is a major causative agent of gastric cancer.Therefore,it has long been argued that H.pylori infection may affect the development of EBVaGC,a subtype of gastric cancer.Atrophic gastrointestinal inflammation,a symptom of H.pylori infection,is observed in the gastric mucosa of EBVaGC.Therefore,it remains unclear whether H.pylori infection is a cofactor for gastric carcinogenesis caused by EBV infection or whether H.pylori and EBV infections act independently on gastric cancer formation.It has been reported that EBV infection assists in the oncogenesis of gastric cancer caused by H.pylori infection.In contrast,several studies have reported that H.pylori infection accelerates tumorigenesis initiated by EBV infection.By reviewing both clinical epidemiological and experimental data,we reorganized the role of H.pylori and EBV infections in gastric cancer formation.展开更多
基金Supported by(in part)Grant-in-Aid for Scientific Research from the Ministry of EducationCulture,Science and Technology of Japan,No.26460546(to Yoshiyama H)
文摘Microbiota in human alimentary tract plays important roles for homeostatic maintenance of the body. Compositional difference of gut microbiota is tightly associated with susceptibility of many diseases,including inflammatory diseases,obesity,diabetes mellitus,cancer,and atherosclerosis. "Dysbiosis" refers to a state of imbalance among the colonies of microorganisms within the body,which brings abnormal increase of specific minor components and decrease in the normally dominant species. Since stomach secrets strong acid for its digestive role,this organ has long been thought a sterile organ. However,the discovery of Helicobacter pylori(H. pylori) has changed the concept. This bacterium has proven to cause gastritis,peptic ulcer,and gastric cancer. However,recent cross-sectional studies revealed that H. pylori carriers had a decreased risk of developing immunological diseases,such as asthma. H. pylori coinfection also suppresses inflammatory bowel diseases. This review describes human gastric microbiota by discussing its mutual interaction and pathogenic enrollment. Gastric "dysbiosis" may affect host inflammatory response and play important role for gastric pathogenesis. We will topically discuss enrollment of dysbiosis for genesis of gastric cancer as well as for disruption of immunological homeostasis affecting oncogenic resistance.
基金Supported by Grant-in-Aid for Scientific Research From the Ministry of Education,Culture,Science and Technology of Japan,No.21K07054(Hironori Yoshiyama)and No.22K07101(Hisashi Iizasa).
文摘Epstein-Barr virus(EBV)-associated gastric cancer(EBVaGC)cells originate from a single-cell clone infected with EBV.However,more than 95%of patients with gastric cancer have a history of Helicobacter pylori(H.pylori)infection,and H.pylori is a major causative agent of gastric cancer.Therefore,it has long been argued that H.pylori infection may affect the development of EBVaGC,a subtype of gastric cancer.Atrophic gastrointestinal inflammation,a symptom of H.pylori infection,is observed in the gastric mucosa of EBVaGC.Therefore,it remains unclear whether H.pylori infection is a cofactor for gastric carcinogenesis caused by EBV infection or whether H.pylori and EBV infections act independently on gastric cancer formation.It has been reported that EBV infection assists in the oncogenesis of gastric cancer caused by H.pylori infection.In contrast,several studies have reported that H.pylori infection accelerates tumorigenesis initiated by EBV infection.By reviewing both clinical epidemiological and experimental data,we reorganized the role of H.pylori and EBV infections in gastric cancer formation.
