title: Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months.
abstract: BACKGROUND
  The gut microbiota is essential to human health throughout life, yet the acquisition and development of this microbial community during infancy remains poorly understood. Meanwhile, there is increasing concern over rising rates of cesarean delivery and insufficient exclusive breastfeeding of infants in developed countries. In this article, we characterize the gut microbiota of healthy Canadian infants and describe the influence of cesarean delivery and formula feeding.
  
  
  METHODS
  We included a subset of 24 term infants from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort. Mode of delivery was obtained from medical records, and mothers were asked to report on infant diet and medication use. Fecal samples were collected at 4 months of age, and we characterized the microbiota composition using high-throughput DNA sequencing.
  
  
  RESULTS
  We observed high variability in the profiles of fecal microbiota among the infants. The profiles were generally dominated by Actinobacteria (mainly the genus Bifidobacterium) and Firmicutes (with diverse representation from numerous genera). Compared with breastfed infants, formula-fed infants had increased richness of species, with overrepresentation of Clostridium difficile. Escherichia-Shigella and Bacteroides species were underrepresented in infants born by cesarean delivery. Infants born by elective cesarean delivery had particularly low bacterial richness and diversity.
  
  
  CONCLUSIONS
  These findings advance our understanding of the gut microbiota in healthy infants. They also provide new evidence for the effects of delivery mode and infant diet as determinants of this essential microbial community in early life.
authors: Department of Pediatrics, University of Alberta, Edmonton, Alta.
authors: Meghan B
authors: MB
authors: Azad
authors: Theodore
authors: T
authors: Konya
authors: Heather
authors: H
authors: Maughan
authors: David S
authors: DS
authors: Guttman
authors: Catherine J
authors: CJ
authors: Field
authors: Radha S
authors: RS
authors: Chari
authors: Malcolm R
authors: MR
authors: Sears
authors: Allan B
authors: AB
authors: Becker
authors: James A
authors: JA
authors: Scott
authors: Anita L
authors: AL
authors: Kozyrskyj
mesh_terms: D001903:Bottle Feeding / Q000379:methods; D001942:Breast Feeding / Q000379:methods; D002170:Canada; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000379:methods*; D004032:Diet; D005243:Feces / Q000382:microbiology*; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology* / Q000502:physiology; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D041943:Infant Formula; D007231:Infant, Newborn; D008297:Male; D050296:Microbial Viability
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