title: Intestinal defensin secretion in infancy is associated with the emergence of sensitization and atopic dermatitis.
abstract: BACKGROUND
  Intestinal flora and innate immunity, and their interactions impact adaptive immunity.
  
  
  OBJECTIVE
  To study the association of fecal defensin levels in infancy with synbiotic treatment and with the emergence of atopy.
  
  
  METHODS
  The randomly selected group of 102 infants belonged to a randomized, double-blind placebo-controlled trial where 1223 infants in high risk for allergy received, from birth to 6 months, a mixture of synbiotics, or placebo. Clinical trials registration number for the clinical trial is NCT00298337. In the subgroup, 45 received active treatment and 56 received placebo treatment. Follow-up for the emergence of sensitization and allergic diseases lasted 5 years. At the age of 3 (n = 96) and 6 (n = 87) months, we measured fecal levels of human neutrophil peptide (HNP) 1-3 and of β-defensin 2 (HBD2) using enzyme linked immunosorbent assays and concentrations of lactic acid bacteria on MRS agar. We used multifactorial regression in data analysis.
  
  
  RESULTS
  Fecal levels of HNP1-3 and HBD2 decreased from the age of 3-6 months (P < 0.0001). HBD2 levels decreased less in the synbiotics group compared with placebo (P < 0.02). High fecal HBD2 levels at 6 months were associated with an increased risk for sensitization by the age of 5 years (OR 2.5, 95% confidence interval 1.1-5.8, P < 0.03). High fecal HNP1-3 levels at 6 months were associated with a decreased risk for atopic dermatitis (OR 0.4, 95% CI 0.1-1.0, P < 0.05). Samples with very low or high HBD2 levels at 6 months had low concentrations of lactic acid bacteria (P < 0.02).
  
  
  CONCLUSIONS
  Early innate immunity responses in the gut are associated with the emergence of sensitization and atopic dermatitis later in childhood.
authors.affiliation: Hospital for Children and Adolescents, Helsinki, Finland.
authors.forename: E M
authors.initials: EM
authors.lastname: Savilahti
authors.forename: A K
authors.initials: AK
authors.lastname: Kukkonen
authors.forename: T
authors.initials: T
authors.lastname: Haahtela
authors.forename: T
authors.initials: T
authors.lastname: Tuure
authors.forename: M
authors.initials: M
authors.lastname: Kuitunen
authors.forename: E
authors.initials: E
authors.lastname: Savilahti
mesh_terms: D002675:Child, Preschool; D023082:Defensins / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000517:prevention & control*; D004311:Double-Blind Method; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000517:prevention & control; D007223:Infant; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism; D011247:Pregnancy; D058616:Synbiotics; D023083:beta-Defensins / Q000276:immunology* / Q000378:metabolism
chemical_list: C106641:DEFB4A protein, human; D023082:Defensins; D023083:beta-Defensins