title: Helicobacter pylori colonization is inversely associated with childhood asthma.
abstract: BACKGROUND
  Asthma, a serious health problem worldwide, is becoming more common. Colonization with Helicobacter pylori, a major human indigenous (commensal) microbe, during early life may be relevant to the risk of childhood asthma.
  
  
  METHODS
  We conducted cross-sectional analyses, using data from 7412 participants in the National Health and Nutrition Examination Survey (NHANES) 1999-2000, to assess the association between H. pylori and childhood asthma.
  
  
  RESULTS
  H. pylori seropositivity was inversely associated with onset of asthma before 5 years of age and current asthma in children aged 3-13 years. Among participants 3-19 years of age, the presence of H. pylori was inversely related to ever having had asthma (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.45-1.06), and the inverse association with onset of asthma before 5 years of age was stronger (OR, 0.58; 95% CI, 0.38-0.88). Among participants 3-13 years of age, H. pylori positivity was significantly inversely associated with current asthma (OR, 0.41; 95% CI, 0.24-0.69). H. pylori seropositivity also was inversely related to recent wheezing, allergic rhinitis, and dermatitis, eczema, or rash.
  
  
  CONCLUSIONS
  This study is the first to report an inverse association between H. pylori seropositivity and asthma in children. The findings indicate new directions for research and asthma prevention.
authors.affiliation: Department of Environmental Medicine, School of Medicine, New York University, New York, New York 10016, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Blaser
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001249:Asthma / Q000453:epidemiology / Q000382:microbiology*; D002648:Child; D003430:Cross-Sectional Studies; D016481:Helicobacter Infections / Q000097:blood / Q000453:epidemiology* / Q000276:immunology*; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D006967:Hypersensitivity / Q000382:microbiology*; D012221:Rhinitis, Allergic, Perennial / Q000382:microbiology; D016036:Seroepidemiologic Studies
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial