Objectives : Infancy represents a critical period for growth and development. Food insecurity (defined as the limited availability of nutritionally adequate and safe foods) in early life may have both immediate and long-term health implications. Some limited evidence suggests that food insecurity in adults may influence the gut microbiota composition, perhaps through a lack of dietary diversity. A number of studies also link malnutrition with alterations in the gut microbiota in children. However, associations between food insecurity and the gut microbiota have yet to be explored in children and especially in infants, who may have had little exposure to foods other than human milk and formula.
Methods : Participants were from the Nurture study, a birth cohort of predominately black women and their infants residing in the southeastern United States. We collected stool samples from 68 infants 3 months after birth. Our exposure was household food security status assessed when infants were between 2 and 3 months. We used the US Household Food Security Survey Module: Six-Item Short Form. We grouped scores of 0-1 (full or marginal food security) as food secure and 2-6 (low or very low food security) as food insecure, consistent with prior studies. For the 3-month outcome, we used an Illumina MiSeq to conduct paired-end sequencing of the 16S rRNA V4 region. We used beta-binomial regression to determine differential abundance of microbiota according to food security status. Two-sided FDR corrected p-values < 0.05 were considered significant. We adjusted for delivery method (C-section versus vaginal), breastfeeding (never versus any), and timing of introduction to solid foods (at or before 3 months versus after 3 months of age).
Results : Demographic characteristics of mothers and infants from food insecure households (n=20) resembled those from food secure households (n=45). The relative abundance of 16 microbial amplicon sequence variants were lower in food insecure infants, and 3 microbial amplicon sequence variants were higher in food secure infants (Figure).
Findings from our birth cohort suggest that infants from food insecure households had altered gut microbiota composition at 3 months of age. Future research is warranted to provide mechanistic insight into these potentially novel associations.
Funding Sources : NIDDK, National Institutes of Health