title: Reduced airway microbiota diversity is associated with elevated allergic respiratory inflammation.
abstract: BACKGROUND
  An increased prevalence of allergic disorders in developed countries has been associated with decreased exposure to environmental micro-organisms and an alteration of microbiota colonization. An appropriate model is needed to investigate the mechanisms by which hygiene environment-driven changes in microbiota could regulate allergic disorders.
  
  
  OBJECTIVE
  To discover the correlation between the higher incidence and severity of allergies with the relative hygiene environment in a developed country.
  
  
  METHODS
  Allergic respiratory inflammation was induced in specific pathogen-free and control rats by sensitization and challenge with ovalbumin. The diversity of lower airway bacteria community was analyzed by polymerase chain reaction denaturing gradient gel electrophoresis and sequencing before ovalbumin sensitization. Allergic respiratory inflammation resulting in cellular infiltrate was measured after the last challenge.
  
  
  RESULTS
  The diversity of microbiota in the airway of specific pathogen-free rats decreased compared with the control rats; the more frequent microbiota in the control rats were Proteobacteria and Bacteroidetes. In addition, increased nasal rubbing and sneezing combined with exaggerated IgE production and leukocyte number was observed in ovalbumin-treated specific pathogen-free rats.
  
  
  CONCLUSIONS
  These data indicate that the excessive "hygienic" environment resulted in a decreased bacterial diversity in the airway during infancy, leading to an increased susceptibility to allergic disease.
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China; Department of Laboratory, Jining No 1 People's Hospital, Jining, Shangdong, China.
authors.forename: Wenkai
authors.initials: W
authors.lastname: Yu
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Xingche
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ding
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Pang
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Huajun
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Jieli
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Li
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Microecology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China. Electronic address: wsh2008cn@sina.com.
authors.forename: Shu
authors.initials: S
authors.lastname: Wen
mesh_terms: D000485:Allergens / Q000008:administration & dosage / Q000276:immunology / Q000633:toxicity; D000818:Animals; D018925:Chemokines / Q000235:genetics; D004198:Disease Susceptibility; D007108:Immune Tolerance; D007114:Immunization; D015994:Incidence; D007279:Injections, Subcutaneous; D064307:Microbiota; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology / Q000633:toxicity; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D012130:Respiratory Hypersensitivity / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D012137:Respiratory System / Q000382:microbiology*; D013047:Specific Pathogen-Free Organisms; D013559:Symbiosis
chemical_list: D000485:Allergens; D018925:Chemokines; D012333:RNA, Messenger; D010047:Ovalbumin