Exposure to environmental microorganisms and childhood asthma

Author: Ege, Markus J.; Mayer, Melanie; Normand, Anne-Cecile; Genuneit, Jon; Cookson, William O. C. M.; Braun-Fahrlander, Charlotte; Heederik, Dick; Piarroux, Renaud; von Mutius, Erika; GABRIELA Transregio 22 Study Group

Description: BACKGROUND: Children who grow up in environments that afford them a wide range of microbial exposures, such as traditional farms, are protected from childhood asthma and atopy. In previous studies, markers of microbial exposure have been inversely related to these conditions.

METHODS: In two cross-sectional studies, we compared children living on farms with those in a reference group with respect to the prevalence of asthma and atopy and to the diversity of microbial exposure. In one study–PARSIFAL (Prevention of Allergy-Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle)–samples of mattress dust were screened for bacterial DNA with the use of single-strand conformation polymorphism (SSCP) analyses to detect environmental bacteria that cannot be measured by means of culture techniques. In the other study–GABRIELA (Multidisciplinary Study to Identify the Genetic and Environmental Causes of Asthma in the European Community [GABRIEL] Advanced Study)–samples of settled dust from children’s rooms were evaluated for bacterial and fungal taxa with the use of culture techniques.

RESULTS: In both studies, children who lived on farms had lower prevalences of asthma and atopy and were exposed to a greater variety of environmental microorganisms than the children in the reference group. In turn, diversity of microbial exposure was inversely related to the risk of asthma (odds ratio for PARSIFAL, 0.62; 95% confidence interval [CI], 0.44 to 0.89; odds ratio for GABRIELA, 0.86; 95% CI, 0.75 to 0.99). In addition, the presence of certain more circumscribed exposures was also inversely related to the risk of asthma; this included exposure to species in the fungal taxon eurotium (adjusted odds ratio, 0.37; 95% CI, 0.18 to 0.76) and to a variety of bacterial species, including Listeria monocytogenes, bacillus species, corynebacterium species, and others (adjusted odds ratio, 0.57; 95% CI, 0.38 to 0.86).

CONCLUSIONS: Children living on farms were exposed to a wider range of microbes than were children in the reference group, and this exposure explains a substantial fraction of the inverse relation between asthma and growing up on a farm.

Subject headings: Adolescent; Agriculture; Asthma; Bacteria; Biodiversity; Child; Cross-Sectional Studies; Dust; Environmental Exposure; Female; Fungi; Humans; Hypersensitivity; Immunoglobulin E; Logistic Models; Male; Polymorphism; Single-Stranded Conformational; Prevalence; Risk Factors; Surveys and Questionnaires; Microbiome; Microbiota

Publication year: 2011

Journal or book title: The New England Journal of Medicine

Volume: 364

Issue: 8

Pages: 701–709

Find the full text: https://www.nejm.org/doi/full/10.1056/NEJMoa1007302

Find more like this one (cited by): https://scholar.google.com/scholar?cites=6011086956156017308&as_sdt=1000005&sciodt=0,16&hl=en

Type: Journal Article

Serial number: 3140

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.