title: Gastric acid reduction leads to an alteration in lower intestinal microflora.
abstract: To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.
authors.affiliation: Department of Gastroenterology, Wakayama Medical University, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kanno
authors.forename: Takahiro
authors.initials: T
authors.lastname: Matsuki
authors.forename: Masashi
authors.initials: M
authors.lastname: Oka
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Utsunomiya
authors.forename: Kenichi
authors.initials: K
authors.lastname: Inada
authors.forename: Hirohito
authors.initials: H
authors.lastname: Magari
authors.forename: Izumi
authors.initials: I
authors.lastname: Inoue
authors.forename: Takao
authors.initials: T
authors.lastname: Maekita
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ueda
authors.forename: Shotaro
authors.initials: S
authors.lastname: Enomoto
authors.forename: Mikitaka
authors.initials: M
authors.lastname: Iguchi
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Yanaoka
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tamai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Akimoto
authors.forename: Koji
authors.initials: K
authors.lastname: Nomoto
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Tanaka
authors.forename: Masao
authors.initials: M
authors.lastname: Ichinose
mesh_terms: D000328:Adult; D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification; D003106:Colon / Q000382:microbiology*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D017208:Rats, Wistar