title: Investigation of the immunomodulatory effects of Lactobacillus casei and Bifidobacterium lactis on Helicobacter pylori infection.
abstract: BACKGROUND
  Lactobacillus and Bifidobacterium species have shown beneficial effects in the treatment of Helicobacter pylori infection; however, the mechanisms behind such effects are not fully understood. In this study, we have investigated the immunomodulatory effects of probiotics in a mouse model of H. pylori infection.
  
  
  METHODS
  H. pylori-infected C57BL/6 mice were treated with L. casei L26, B. lactis B94, or no probiotics for 5 weeks, respectively. Mice not infected with H. pylori were included as normal controls. Gastric histology, protein levels of interleukin (IL)-1beta, IL-10, IL-12/23p40, and H. pylori colonization density in the gastric tissues, as well as H. pylori-specific antibodies were examined.
  
  
  RESULTS
  In mice receiving L. casei L26 and B. lactis B94, gastric neutrophil infiltration and IL-1beta were significantly decreased and IL-10 was significantly increased as compared with mice receiving no probiotics. In mice receiving B. lactis B94, IL-12/23p40 was significantly increased and H. pylori IgG was significantly reduced as compared with mice receiving no probiotics. No significant difference of H. pylori colonization was observed among the three groups of mice.
  
  
  CONCLUSIONS
  The reduced level of IL-1beta and neutrophil infiltration observed in mice infected with H. pylori following treatment with L. casei L26 and B. lactis B94 resulted from a modulation of immune response rather than a decrease of H. pylori colonization. Furthermore, B. lactis B94 has the intrinsic ability to promote a Th1 immune response through an increase in IL-12/IL-23.
authors.affiliation: The School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Su
authors.forename: Anders
authors.initials: A
authors.lastname: Henriksson
authors.forename: Jani
authors.initials: J
authors.lastname: O'Rourke
authors.forename: Hazel
authors.initials: H
authors.lastname: Mitchell
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000145:classification / Q000254:growth & development / Q000276:immunology*; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology* / Q000473:pathology; D016480:Helicobacter pylori; D016753:Interleukin-10 / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D053583:Interleukin-1beta / Q000276:immunology; D053759:Interleukin-23 / Q000276:immunology; D007780:Lacticaseibacillus casei / Q000254:growth & development / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D019936:Probiotics
chemical_list: D053583:Interleukin-1beta; D053759:Interleukin-23; D016753:Interleukin-10; D018664:Interleukin-12