Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months – cover

Date: 2013-03-05

Reference number: OPUSeJ 201303011338GMI

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Title: Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months

Authors:  Meghan B. Azad, Theodore Konya, Heather Maughan, David S. Guttman, Catherine J. Field, Radha S. Chari, Malcolm R. Sears, Allan B. Becker, James A. Scott, Anita L. Kozyrskyj, on behalf of the CHILD Study Investigators


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.

Interpretation: 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.

Author bio:  N/A

Sponsor editor:  N/A


From the Departments of Pediatrics (Azad, Kozyrskyj), Agricultural, Food and Nutritional Sciences (Field), and Obstetrics and Gynecology (Chari), University of Alberta, Edmonton, Alta.; the Dalla Lana School of Public Health (Konya, Scott) and the Centre for the Analysis of Genome Evolution and Function (Maughan, Guttman), University of Toronto, Toronto, Ont.; the Department of Medicine (Sears), McMaster University, Hamilton, Ont.; the Department of Pediatrics and Child Health (Becker), University of Manitoba, Winnipeg, Man.; and the Manitoba Institute of Child Health (Becker, Kozyrskyj), Winnipeg, Man.

Allan Becker is an advisory board member for Merck, Novartis and AstraZeneca; his institution has received research grants from Merck and AstraZeneca. No competing interests were declared by the other authors.

This research was funded by the Canadian Institutes of Health Research (grant nos. 85761 and 227312), and was supported by AllerGen NCE, the Killam Trusts and Alberta Innovates — Health Solutions.

The authors extend sincere appreciation to all of the study families and the CHILD research teams. They also thank Yiye Zeng for help with the statistical analysis and Brenda Koster for bioinformatics support.

Keywords:  N/A

Subject:  Science/ gut microbiota

Language: English

Bibliography: see Forum

Citation: Azad, M B et al, 2013, “Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months”, Canadian Medical Association Journal, Published online February 11, 2013, doi: 10.1503/cmaj.121189.

References: see Forum

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