title: Airway Microbiota in Severe Asthma and Relationship to Asthma Severity and Phenotypes.
abstract: BACKGROUND
  The lower airways harbor a community of bacterial species which is altered in asthma.
  
  
  OBJECTIVE
  We examined whether the lower airway microbiota were related to measures of asthma severity.
  
  
  METHODS
  We prospectively recruited 26 severe asthma, 18 non-severe asthma and 12 healthy subjects. DNA was extracted from induced sputum and PCR amplification of the V3-V5 region of bacterial 16S rRNA gene was performed.
  
  
  RESULTS
  We obtained 138,218 high quality sequences which were rarefied at 133 sequences/sample. Twenty OTUs had sequences ≥1% of total. There were marked differences in the distribution of Phyla between groups (P = 2.8x10-118). Bacteroidetes and Fusobacteria were reduced in non-severe and severe asthmatic groups. Proteobacteria were more common in non-severe asthmatics compared to controls (OR = 2.26; 95% CI = 1.94-2.64) and Firmicutes were increased in severe asthmatics compared to controls (OR = 2.15; 95%CI = 1.89-2.45). Streptococcal OTUs amongst the Firmicutes were associated with recent onset asthma, rhinosinusitis and sputum eosinophilia.
  
  
  CONCLUSIONS
  Sputum microbiota in severe asthma differs from healthy controls and non-severe asthmatics, and is characterized by the presence of Streptococcus spp with eosinophilia. Whether these organisms are causative for the pathophysiology of asthma remains to be determined.
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.|State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Cox
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.|State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
authors.forename: Zhike
authors.initials: Z
authors.lastname: Liang
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.
authors.forename: Folke
authors.initials: F
authors.lastname: Brinkmann
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Cardenas
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.
authors.forename: Rachael
authors.initials: R
authors.lastname: Duff
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Bhavsar
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Cookson
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.
authors.forename: Miriam
authors.initials: M
authors.lastname: Moffatt
authors.affiliation: National Heart & Lung Institute, Imperial College, London, United Kingdom.|Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Trust and Imperial College London, United Kingdom.|State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
authors.forename: Kian Fan
authors.initials: KF
authors.lastname: Chung
mesh_terms: D000328:Adult; D001249:Asthma / Q000382:microbiology* / Q000503:physiopathology; D002452:Cell Count; D005260:Female; D006801:Humans; D008168:Lung / Q000382:microbiology / Q000503:physiopathology; D008297:Male; D064307:Microbiota / Q000235:genetics; D008875:Middle Aged; D010641:Phenotype; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013183:Sputum / Q000382:microbiology
chemical_list: D012336:RNA, Ribosomal, 16S