title: The Fecal Microbiota Profile and Bronchiolitis in Infants.
abstract: Little is known about the association of gut microbiota, a potentially modifiable factor, with bronchiolitis in infants. We aimed to determine the association of fecal microbiota with bronchiolitis in infants.
  
  
  
  We conducted a case-control study. As a part of multicenter prospective study, we collected stool samples from 40 infants hospitalized with bronchiolitis. We concurrently enrolled 115 age-matched healthy controls. By applying 16S rRNA gene sequencing and an unbiased clustering approach to these 155 fecal samples, we identified microbiota profiles and determined the association of microbiota profiles with likelihood of bronchiolitis.
  
  
  
  Overall, the median age was 3 months, 55% were male, and 54% were non-Hispanic white. Unbiased clustering of fecal microbiota identified 4 distinct profiles: Escherichia-dominant profile (30%), Bifidobacterium-dominant profile (21%), Enterobacter/Veillonella-dominant profile (22%), and Bacteroides-dominant profile (28%). The proportion of bronchiolitis was lowest in infants with the Enterobacter/Veillonella-dominant profile (15%) and highest in the Bacteroides-dominant profile (44%), corresponding to an odds ratio of 4.59 (95% confidence interval, 1.58-15.5; P = .008). In the multivariable model, the significant association between the Bacteroides-dominant profile and a greater likelihood of bronchiolitis persisted (odds ratio for comparison with the Enterobacter/Veillonella-dominant profile, 4.24; 95% confidence interval, 1.56-12.0; P = .005). In contrast, the likelihood of bronchiolitis in infants with the Escherichia-dominant or Bifidobacterium-dominant profile was not significantly different compared with those with the Enterobacter/Veillonella-dominant profile.
  
  
  
  In this case-control study, we identified 4 distinct fecal microbiota profiles in infants. The Bacteroides-dominant profile was associated with a higher likelihood of bronchiolitis.
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; khasegawa1@partners.org.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hasegawa
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia;
authors.forename: Rachel W
authors.initials: RW
authors.lastname: Linnemann
authors.affiliation: Department of Medicine, Boston Children's Hospital, Boston, Massachusetts;
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Mansbach
authors.affiliation: Alkek Center for Metagenomics and Microbiome Research and.
authors.forename: Nadim J
authors.initials: NJ
authors.lastname: Ajami
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
authors.forename: Janice A
authors.initials: JA
authors.lastname: Espinola
authors.affiliation: Alkek Center for Metagenomics and Microbiome Research and.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Petrosino
authors.affiliation: Department of Molecular Virology and Microbiology, and Pediatrics, Baylor College of Medicine, Houston, Texas;
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Piedra
authors.affiliation: Kosair Children's Hospital, Louisville, Kentucky; and.
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Stevenson
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
authors.forename: Ashley F
authors.initials: AF
authors.lastname: Sullivan
authors.affiliation: Alfred I. duPont Hospital for Children, Wilmington, Delaware.
authors.forename: Amy D
authors.initials: AD
authors.lastname: Thompson
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
mesh_terms: D001988:Bronchiolitis / Q000382:microbiology*; D016022:Case-Control Studies; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D064307:Microbiota; D011446:Prospective Studies