Jenni Lehtimäki1, Jonathan Thorsen2, Morten Arendt Rasmussen3, Mathis Hjelmsø1, Shiraz Shah1, Martin S Mortensen4, Urvish Trivedi5, Gisle Vestergaard6, Klaus Bønnelykke1, Bo Lund Chawes1, Susanne Brix7, Søren J Sørensen5, Hans Bisgaard8, Jakob Stokholm1. 1. Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark. 2. Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. 3. Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark; Section of Chemometrics and Analytical Technologies, Department of Food Science, University of Copenhagen, Frederiksberg, Denmark. 4. Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Host-Microbiota Interactions Laboratory, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom. 5. Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark. 6. Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Section for Bioinformatics, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark. 7. Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark. 8. Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark. Electronic address: bisgaard@copsac.com.
Abstract
BACKGROUND: Urbanization is linked with an increased burden of asthma and atopic traits. A putative mechanism is insufficient exposure to beneficial microbes early in life, leading to immune dysregulation, as was previously shown for indoor microbial exposures. OBJECTIVE: Our aim was to investigate whether urbanization is associated with the microbiota composition in the infants' body and early immune function, and whether these contribute to the later risk of asthma and atopic traits. METHODS: We studied the prospective Copenhagen Prospective Studies on Asthma in Childhood 20102010 mother-child cohort of 700 children growing up in areas with different degrees of urbanization. During their first year of life, airway and gut microbiotas, as well as immune marker concentrations, were defined. When the children were 6 years of age, asthma and atopic traits were diagnosed by pediatricians. RESULTS: In adjusted analyses, the risk of asthma and aeroallergen sensitization were increased in urban infants. The composition of especially airway but also gut microbiotas differed between urban and rural infants. The living environment-related structure of the airway microbiota was already associated with immune mediator concentrations at 1 month of age. An urbanized structure of the airway and gut microbiotas was associated with an increased risk of asthma coherently during multiple time points and also with the risks of eczema and sensitization. CONCLUSION: Our findings suggest that urbanization-related changes in the infant microbiota may elevate the risk of asthma and atopic traits, probably via cross talk with the developing immune system. The airways may facilitate this effect, as they are open for colonization by environmental airborne microbes and serve as an immune interface.
BACKGROUND: Urbanization is linked with an increased burden of asthma and atopic traits. A putative mechanism is insufficient exposure to beneficial microbes early in life, leading to immune dysregulation, as was previously shown for indoor microbial exposures. OBJECTIVE: Our aim was to investigate whether urbanization is associated with the microbiota composition in the infants' body and early immune function, and whether these contribute to the later risk of asthma and atopic traits. METHODS: We studied the prospective Copenhagen Prospective Studies on Asthma in Childhood 20102010 mother-child cohort of 700 children growing up in areas with different degrees of urbanization. During their first year of life, airway and gut microbiotas, as well as immune marker concentrations, were defined. When the children were 6 years of age, asthma and atopic traits were diagnosed by pediatricians. RESULTS: In adjusted analyses, the risk of asthma and aeroallergen sensitization were increased in urban infants. The composition of especially airway but also gut microbiotas differed between urban and rural infants. The living environment-related structure of the airway microbiota was already associated with immune mediator concentrations at 1 month of age. An urbanized structure of the airway and gut microbiotas was associated with an increased risk of asthma coherently during multiple time points and also with the risks of eczema and sensitization. CONCLUSION: Our findings suggest that urbanization-related changes in the infant microbiota may elevate the risk of asthma and atopic traits, probably via cross talk with the developing immune system. The airways may facilitate this effect, as they are open for colonization by environmental airborne microbes and serve as an immune interface.
Authors: Emil Dalgaard Christensen; Mathis Hjort Hjelmsø; Morten Arendt Rasmussen; Jakob Stokholm; Jonathan Thorsen; Shiraz Shah; Tamsin Redgwell; Christina Egeø Poulsen; Urvish Trivedi; Jakob Russel; Shashank Gupta; Bo L Chawes; Klaus Bønnelykke; Søren Johannes Sørensen; Hans Bisgaard Journal: Microbiome Date: 2022-07-13 Impact factor: 16.837
Authors: Siti Muhamad Nur Husna; Hern-Tze Tina Tan; Norasnieda Md Shukri; Noor Suryani Mohd Ashari; Kah Keng Wong Journal: Front Med (Lausanne) Date: 2022-04-07