title: Extensive atrophic gastritis linked to increased levels of intraluminal hydrogen gas.
abstract: OBJECTIVE
  Gastric acid plays an important part in the prevention of bacterial colonization of the gastrointestinal tract. If these bacteria have an ability of hydrogen (H2) fermentation, intraluminal H2 gas might be detected. We attempted to measure the intraluminal H2 concentrations to determine the bacterial overgrowth in the gastrointestinal tract.
  
  
  METHODS
  Studies were performed in 647 consecutive patients undergoing upper endoscopy. At the time of endoscopic examination, we intubated the stomach and the descending part of the duodenum without inflation by air, and 20 ml of intraluminal gas samples of both sites was collected through the biopsy channel. Intraluminal H2 concentrations were measured by gas chromatography.
  
  
  RESULTS
  Over all, intragastric and intraduodenal H2 gas was detected in 566 (87.5%) and 524 (81.0%), respectively. The mean values of intragastric and intraduodenal H2 gas were 8.5 +/- 15.9 and 13.2 +/- 58.0 ppm, respectively. The intraduodenal H2 level was increased with the progression of atrophic gastritis, whereas the intragastric H2 level was the highest in patients without atrophic gastritis.
  
  
  CONCLUSIONS
  The intraduodenal hydrogen levels were increased with the progression of atrophic gastritis. It is likely that the influence of hypochlorhydria on bacterial overgrowth in the proximal small intestine is more pronounced, compared to that in the stomach.
authors.affiliation: Department of General Medicine and Emergency Care, Toho University School of Medicine Omori Hospital, Tokyo, Japan. foo@eb.mbn.or.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Urita
authors.forename: Toshiyasu
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tadashi
authors.initials: T
authors.lastname: Maeda
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Takamasa
authors.initials: T
authors.lastname: Ishii
authors.forename: Tatsuhiro
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Akiro
authors.initials: A
authors.lastname: Kugahara
authors.forename: Asuka
authors.initials: A
authors.lastname: Nakayama
authors.forename: Makie
authors.initials: M
authors.lastname: Nanami
authors.forename: Kaoru
authors.initials: K
authors.lastname: Domon
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishihara
authors.forename: Hirohito
authors.initials: H
authors.lastname: Kato
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hike
authors.forename: Masaki
authors.initials: M
authors.lastname: Sanaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Motonobu
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Miki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000254:growth & development*; D004386:Duodenum / Q000378:metabolism* / Q000382:microbiology; D005260:Female; D005745:Gastric Acidity Determination; D005757:Gastritis, Atrophic / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013270:Stomach / Q000382:microbiology