{
  "abstract": "Background Asthma is an umbrella diagnosis encompassing distinct pathophysiological mechanisms. While a global problem, our understanding of the interplay between respiratory microbiology and airway inflammation is largely from populations in high-income settings. As a result, treatment approaches align poorly with asthma characteristics in less studied populations.Objective To identify conserved and geographically distinct relationships between airway inflammation and microbiota characteristics in young people with and without asthma.Methods We conducted a cross-sectional study performing inflammatory phenotyping, microbiota analysis and enumeration of total bacteria, Haemophilus influenzae and Moraxella catarrhalis on 488 induced sputum samples from participants from Brazil (asthma: 68; non-asthma: 8), Ecuador (asthma: 89; non-asthma: 30), Uganda (asthma: 61; non-asthma: 8), New Zealand (asthma: 129; non-asthma: 58) and the UK (asthma: 25; non-asthma: 20). Microbiota characteristics were compared by country, asthma status and inflammatory characteristics, adjusting for age and sex.Results Asthma inflammatory phenotypes and microbiology differed between countries, with Uganda characterised by higher neutrophils, microbial diversity and bacterial abundance. Comparison of airway inflammation with microbiota characteristics showed conserved relationships across centres, with airway neutrophil proportion explaining variance in microbiota Bray-Curtis dissimilarity (p<0.001) and being positively associated with bacterial abundance, including H. influenzae and M. catarrhalis load (all p<0.05). In contrast, eosinophil proportion was less strongly associated with microbiota dissimilarity (p=0.033) and only associated with Streptococcus abundance. Country-specific associations between airway inflammation and microbiology were evident.Conclusion Both airway inflammation and microbiology varied geographically in young people with asthma. Associations between microbiota characteristics and neutrophilic phenotype were conserved.",
  "authors": [
    {
      "affiliations": [
        "Microbiome and Host Health Programme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia",
        "College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia"
      ],
      "name": "Steven L Taylor"
    },
    {
      "affiliations": [
        "Research Centre for Hauora and Health, Massey University, Wellington, New Zealand"
      ],
      "name": "Collin R Brooks"
    },
    {
      "affiliations": [
        "London School of Hygiene & Tropical Medicine, London, UK"
      ],
      "name": "Lucy Pembrey"
    },
    {
      "affiliations": [
        "Microbiome and Host Health Programme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia"
      ],
      "name": "Sarah K Manning"
    },
    {
      "affiliations": [
        "Microbiome and Host Health Programme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia"
      ],
      "name": "Levi Elms"
    },
    {
      "affiliations": [
        "MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda"
      ],
      "name": "Harriet Mpairwe"
    },
    {
      "affiliations": [
        "Federal University of Bahia Salvador, Salud, Brazil"
      ],
      "name": "Camila A Figueiredo"
    },
    {
      "affiliations": [
        "Fundación Ecuatoriana Para Investigación en Salud, Quito, Ecuador"
      ],
      "name": "Aida Y Oviedo"
    },
    {
      "affiliations": [
        "Fundación Ecuatoriana Para Investigación en Salud, Quito, Ecuador"
      ],
      "name": "Martha Chico"
    },
    {
      "affiliations": [
        "Research Centre for Hauora and Health, Massey University, Wellington, New Zealand"
      ],
      "name": "Jeroen Burmanje"
    },
    {
      "affiliations": [
        "Research Centre for Hauora and Health, Massey University, Wellington, New Zealand"
      ],
      "name": "Hajar Ali"
    },
    {
      "affiliations": [
        "MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda"
      ],
      "name": "Irene Nambuya"
    },
    {
      "affiliations": [
        "MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda"
      ],
      "name": "Pius Tumwesige"
    },
    {
      "affiliations": [
        "London School of Hygiene & Tropical Medicine, London, UK"
      ],
      "name": "Steven Robertson"
    },
    {
      "affiliations": [
        "London School of Hygiene & Tropical Medicine, London, UK"
      ],
      "name": "Charlotte E Rutter"
    },
    {
      "affiliations": [
        "London School of Hygiene & Tropical Medicine, London, UK"
      ],
      "name": "Karin van Veldhoven"
    },
    {
      "affiliations": [
        "Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, Bristol, UK",
        "MRC Integrative Epidemiology Unit, University of Bristol, Bristol, UK"
      ],
      "name": "Susan M Ring"
    },
    {
      "affiliations": [
        "Federal University of Bahia Salvador, Salud, Brazil",
        "Center for Data and Knowledge Integration for Health, Fiocruz, Bahia, Bahia, Brazil"
      ],
      "name": "Mauricio L Barreto"
    },
    {
      "affiliations": [
        "Fundación Ecuatoriana Para Investigación en Salud, Quito, Ecuador",
        "Institute of Infection and Immunity, St George’s University of London, London, UK",
        "School of Medicine, Universidad Internacional del Ecuador, Quito, Pichincha, Ecuador"
      ],
      "name": "Philip J Cooper"
    },
    {
      "affiliations": [
        "Medicine, Federal University of Bahia, Salvador, Bahia, Brazil"
      ],
      "name": "Álvaro A Cruz"
    },
    {
      "affiliations": [
        "London School of Hygiene & Tropical Medicine, London, UK"
      ],
      "name": "Neil Pearce"
    },
    {
      "affiliations": [
        "Microbiome and Host Health Programme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia"
      ],
      "name": "Geraint B Rogers"
    },
    {
      "affiliations": [
        "Research Centre for Hauora and Health, Massey University, Wellington, New Zealand"
      ],
      "name": "Jeroen Douwes"
    },
    {
      "affiliations": [],
      "name": "the WASP Study Group"
    }
  ],
  "title": "Airway microbiota in young people across four continents differ by country, asthma status and inflammatory phenotype",
  "uid": "a704a962-c6a7-5998-9936-71a9d6a30f57"
}