Gastric acid reduction leads to an alteration in lower intestinal microflora

• Published in: Biochemical and biophysical research communications 2009-04, Vol.381 (4), p.666-670
• Main Authors: Kanno, Takayuki, Matsuki, Takahiro, Oka, Masashi, Utsunomiya, Hirotoshi, Inada, Kenichi, Magari, Hirohito, Inoue, Izumi, Maekita, Takao, Ueda, Kazuki, Enomoto, Shotaro, Iguchi, Mikitaka, Yanaoka, Kimihiko, Tamai, Hideyuki, Akimoto, Shigeru, Nomoto, Koji, Tanaka, Ryuichiro, Ichinose, Masao
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Adult; Animals; BACTERIA; Bacteria - classification; Bacteria - isolation & purification; Bacterial overgrowth; Bifidobacterium; Chronic atrophic gastritis; Colon - microbiology; DIFFUSION BARRIERS; FECES; Female; GASTRIC ACID; Gastric Acid - secretion; Gastric acid barrier; Humans; Hypochlorhydria; Intestinal microflora; Lactobacillus; Male; Middle Aged; POLYMERASE CHAIN REACTION; Proton pump inhibitor; PUMPS; RATS; Rats, Wistar; REDUCTION; Veillonella; VENTILATION BARRIERS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2009.02.109

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.