title: Probiotics have a different immunomodulatory potential in vitro versus ex vivo upon oral administration in children with food allergy.
abstract: BACKGROUND
  Previous studies suggest that administration of probiotics in vitro can stimulate regulatory and Th1 immune responses. We studied both the in vitro immunological effects of probiotics and the ex vivo immunological effects after oral administration of probiotics in children with food allergy, a Th2-mediated disease.
  
  
  METHODS
  Thirteen children were enrolled. Probiotics (n = 7) or placebo (n = 6) were orally administered during 3 months. At baseline and after 1 and 3 months, peripheral blood mononuclear cells were stimulated with crude peanut extract, anti-CD3, or anti-CD40 and IL-4 in the presence (in vitro response) or absence (ex vivo response) of probiotics. The proliferation and production of IFN-gamma, IL-5, IL-13, IL-10, TNF-alpha, IL-6 and IgE were analyzed. Sensitization to peanut, cow's milk and hen's egg was determined before and after treatment.
  
  
  RESULTS
  The in vitro addition of probiotics to peripheral blood mononuclear cell cultures resulted in enhanced proliferation and production of IFN-gamma, IL-10 and TNF-alpha. After oral treatment, proliferation in the presence of probiotics increased, whereas in vitro IgE production decreased in the probiotics group compared to baseline. The ex vivo production of IL-10, TNF-alpha and IL-6 tended to decrease. Th1 and Th2 cytokines were not altered. Sensitization remained unchanged.
  
  
  CONCLUSIONS
  Probiotics enhanced the production of Th1 and regulatory cytokines in vitro. Oral administration of probiotics resulted in a slightly decreased ex vivo production of IL-10, TNF-alpha and IL-6. This indicates that probiotics have a different potential to modulate the immune response in vitro versus ex vivo.
authors.affiliation: Department of Dermatology and Allergology, UMC Utrecht, Utrecht, The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: Flinterman
authors.forename: E F
authors.initials: EF
authors.lastname: Knol
authors.forename: A G
authors.initials: AG
authors.lastname: van Ieperen-van Dijk
authors.forename: H M
authors.initials: HM
authors.lastname: Timmerman
authors.forename: A C
authors.initials: AC
authors.lastname: Knulst
authors.forename: C A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: S G M A
authors.initials: SG
authors.lastname: Pasmans
authors.forename: E
authors.initials: E
authors.lastname: van Hoffen
mesh_terms: D000284:Administration, Oral; D049109:Cell Proliferation / Q000187:drug effects; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005512:Food Hypersensitivity / Q000517:prevention & control*; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000187:drug effects; D066298:In Vitro Techniques; D007223:Infant; D007371:Interferon-gamma / Q000096:biosynthesis / Q000187:drug effects; D016753:Interleukin-10 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D008297:Male; D019936:Probiotics / Q000008:administration & dosage*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000187:drug effects
chemical_list: D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D007073:Immunoglobulin E; D007371:Interferon-gamma