title: Strain-specific inhibition of Helicobacter pylori by Lactobacillus salivarius and other lactobacilli.
abstract: OBJECTIVE
  To investigate the anti-Helicobacter pylori activity of 28 strains of Lactobacillus salivarius and 12 other lactobacilli, isolated from different sites and from different geographical regions.
  
  
  METHODS
  An in vitro agar plate diffusion assay was employed to assess the Lactobacillus anti-H. pylori activity.
  
  
  RESULTS
  Nine out of 28 L. salivarius strains and 3/12 other Lactobacillus species tested inhibited H. pylori growth. There was no correlation between ecological niche/geographical location of isolation of the lactobacilli and their inhibitory capability. Further studies on strain L. salivarius UCC119 showed that this strain could inhibit growth of 6/6 clinical isolates of H. pylori, five of which were antibiotic-resistant. This inhibition was not due to acid production and was not mediated by a protein, but did require the presence of live cells.
  
  
  CONCLUSIONS
  Growth inhibition of H. pylori by L. salivarius is strain-dependent and is not linked to any particular environmental niche or geographic location. Strains of L. salivarius showing highest anti-H. pylori activity may be useful as an adjunct in the treatment of strains that are resistant to conventional antibiotics.
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
authors.forename: Kieran A
authors.initials: KA
authors.lastname: Ryan
authors.forename: Paul
authors.initials: P
authors.lastname: Daly
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.forename: Carmel
authors.initials: C
authors.lastname: Hooton
authors.forename: Paul W
authors.initials: PW
authors.lastname: O'Toole
mesh_terms: D000898:Antibiosis; D001426:Bacterial Proteins / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000254:growth & development*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media