title: Analysis of Gastric Microbiota by Pyrosequencing: Minor Role of Bacteria Other Than Helicobacter pylori in the Gastric Carcinogenesis.
abstract: BACKGROUND
  Little is known about the role of gastric microbiota except for Helicobacter pylori (HP) in human health and disease. We compared the differences of human gastric microbiota according to gastric cancer or control and HP infection status and assessed the role of bacteria other than HP.
  
  
  METHODS
  Gastric microbiota of 63 antral mucosal and 18 corpus mucosal samples were analyzed by bar-coded 454 pyrosequencing of the 16S rRNA gene. Antral samples were divided into four subgroups based on HP positivity in pyrosequencing and the presence of cancer. The analysis was focused on bacteria other than HP, especially nitrosating or nitrate-reducing bacteria (NB). The changes of NB in antral mucosa of 16 subjects were followed up.
  
  
  RESULTS
  The number of NB other than HP (non-HP-NB) was two times higher in the cancer groups than in the control groups, but it did not reach statistical significance. The number of non-HP-NB tends to increase over time, but this phenomenon was prevented by HP eradication in the HP-positive control group, but not in the HP-positive cancer group.
  
  
  CONCLUSIONS
  We could not find the significant role of bacteria other than HP in the gastric carcinogenesis.
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Jo
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jaeyeon
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea. nayoungkim49@empas.com.|Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea. nayoungkim49@empas.com.
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ryoung Hee
authors.initials: RH
authors.lastname: Nam
authors.affiliation: Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, Korea.
authors.forename: Yeong-Jae
authors.initials: YJ
authors.lastname: Seok
authors.affiliation: Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, Korea.
authors.forename: Yeon-Ran
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Joo Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Microbiology, College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Jung Mogg
authors.initials: JM
authors.lastname: Kim
authors.affiliation: NAR Center, Inc., Daejeon Oriental Hospital of Daejeon University, Daejeon, South Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyun Chae
authors.initials: HC
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification* / Q000472:pathogenicity; D063646:Carcinogenesis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology*; D006801:Humans; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013274:Stomach Neoplasms / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: Gastric cancer; Helicobacter pylori; gastric microbiota; nitrate-reducing bacteria; nitrosating bacteria; pyrosequencing