Factors influencing the infant gut microbiome in an ethnically diverse population


Published online: October 13, 2016

The gut microbiome in infancy influences immune system maturation, and may have an important impact on allergic disease risk in childhood. Before delving into studies of the early life gut microbiome and health outcomes, we must first understand the factors that impact the establishment of the gut microbiome in infancy.

In a recent publication in The Journal of Allergy and Clinical Immunology (JACI), Sordillo and colleagues report on associations between prenatal and early life factors and the infant gut microbiome in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a large ethnically diverse study population. In this work, the authors examined factors including race, circumstances of labor and delivery, gestational age at birth, feeding practices, and home exposures in relation to the infant gut microbiome. Stool samples were collected from 333 infants (age 3-6 months) and 16S rRNA gene sequencing was performed to determine microbiome composition. Factor analysis of the top 25 most abundant taxa revealed 4 underlying bacterial co-abundance groups within the infant gut microbiome; the first dominated by Firmicutes (Lachnospiraceae/Clostridales), the second by Proteobacteria (Klebsiella/Enterobacter), the third by Bacteroidetes, and the fourth by Veillonella.

The authors report that black race/ethnicity, ceasarean section and formula feeding (all asthma risk factors), are associated with altered taxonomic composition of the infant gut microbiome. Black race/ethnicity and ceasarean section were independent predictors of lower levels of Bacteroidetes in the infant gut. Formula feeding was linked to higher levels of Clostridia in the infant gut, which may be associated with increased risk of allergic disease. Cord blood vitamin D was linked to increased Lachnospiraceae, but decreased Lactococcus. Future work is required to uncover how alterations in infant gut microbial communities influence diseases of immune origin in childhood.      

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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