title: Microbes and asthma: Opportunities for intervention.
abstract: The worldwide incidence and prevalence of asthma continues to increase. Asthma is now understood as an umbrella term for different phenotypes or endotypes, which arise through different pathophysiologic pathways. Understanding the many factors contributing to development of the disease is important for the identification of novel therapeutic targets for the treatment of certain asthma phenotypes. The hygiene hypothesis has been formulated to explain the increasing prevalence of allergic disease, including asthma. This hypothesis postulates that decreased exposure at a young age to certain infectious agents as a result of improved hygiene, increased antibiotic use and vaccination, and changes in lifestyle and dietary habits is associated with changes in the immune system, which predispose subjects to allergy. Many microbes, during their coevolution with human subjects, developed mechanisms to manipulate the human immune system and to increase their chances of survival. Improving models of asthma, as well as choosing adequate end points in clinical trials, will lead to a more complete understanding of the underlying mechanisms, thus providing an opportunity to devise primary and secondary interventions at the same time as identifying new molecular targets for treatment. This article reports the discussion and conclusion of a workshop under the auspices of the Netherlands Lung Foundation to extend our understanding of how modulation of the immune system by bacterial, parasitic, and viral infections might affect the development of asthma and to map out future lines of investigation.
authors.affiliation: Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: h.h.smits@lumc.nl.
authors.forename: Hermelijn H
authors.initials: HH
authors.lastname: Smits
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Pieter S
authors.initials: PS
authors.lastname: Hiemstra
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technische Universät München, Munich, Germany.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Prazeres da Costa
authors.affiliation: Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität of Munich, Munich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Ege
authors.affiliation: Department of Respiratory Medicine & Wright-Fleming Institute of Infection and Immunity, Imperial College London, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Edwards
authors.affiliation: Institute for Laboratory Medicine and Pathobiochemistry, Philipps University of Marburg, Marburg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Garn
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, University Hospital Southampton, Southampton, United Kingdom.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Howarth
authors.affiliation: Department of Pediatrics, Turku University Hospital, Turku, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Jartti
authors.affiliation: Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Esther C
authors.initials: EC
authors.lastname: de Jong
authors.affiliation: Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Rick M
authors.initials: RM
authors.lastname: Maizels
authors.affiliation: Faculty of Biology and Medicine, University of Lausanne, Service de Pneumologie, CHUV, Epalinges, Switzerland.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Marsland
authors.affiliation: Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: McSorley
authors.affiliation: Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
authors.forename: Anne
authors.initials: A
authors.lastname: Müller
authors.affiliation: Comprehensive Biomaterial Bank Marburg (CBBMR), Philipps University Marburg, Marburg, Germany.
authors.forename: Petra I
authors.initials: PI
authors.lastname: Pfefferle
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, Wageningen, The Netherlands.
authors.forename: Huub
authors.initials: H
authors.lastname: Savelkoul
authors.affiliation: MRC-Centre for Inflammation Research, Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schwarze
authors.affiliation: Department of Paediatrics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Wendy W J
authors.initials: WW
authors.lastname: Unger
authors.affiliation: Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität of Munich, Munich, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: von Mutius
authors.affiliation: Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Maria
authors.initials: M
authors.lastname: Yazdanbakhsh
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Christian
authors.initials: C
authors.lastname: Taube
mesh_terms: D000818:Animals; D001249:Asthma / Q000209:etiology* / Q000517:prevention & control / Q000628:therapy; D004198:Disease Susceptibility; D004781:Environmental Exposure; D054884:Host-Pathogen Interactions; D006801:Humans; D006920:Hygiene; D064307:Microbiota / Q000276:immunology
keywords: Hygiene hypothesis; asthma; helminths; immune regulation; microbes; microbiome; sensitization; viruses