Poster Topical Area: Nutritional Immunology
Location: Hall D
Poster Board Number: 851
Objectives: The objective of the study was to determine the persistent effect of infant postnatal diet on the composition of gut microbiota at six and 12 mos of age.
Methods: Infants were recruited based on consumption of either human breast milk (HBM) or formula prior to enrollment at 3 mos of age. Breastfeeding was encouraged until 12 mos of age in the HBM group, but when not possible infants were provided with dairy milk-based formula at six mos of age. All formula-fed infants consumed either soy (SF) or dairy-based milk formula (MF) until 12 mos of age. Solid food could be introduced to infants in all diet groups by 4 mos of age. Infant fecal samples collected at six mos (HBM: n=28; MF: n=24; SF: n=17) and 12 mos (HBM: n=28; MF: n=14; SF: n=18) of age were assessed for 16S rRNA gene amplicon sequencing and analyzed using QIIME 1.91. Group differences of α- and β-diversity, and differential abundance were assessed in R using DAME.
Results: At the genus level, there was less α-diversity (Shannon index) in HBM relative to the SF and MF groups at six mos of age (p<0.05). At 12 mos of age, no differences were observed in α-diversity at the genus level across diet groups. At six and 12 mos of age, Bray-Curtis dissimilarity estimate of β-diversity showed separation of HBM from the SF group at the genus level (PERMANOVA; p<0.05). The relative abundance of Firmicutes and Proteobacteria was lower in the HBM and MF groups than SF at six (q<0.05) but not 12 mos of age. The relative abundance of Actinobacteria was higher in the HBM and MF groups than SF at six and 12 mos of age (q<0.05). The relative abundance of Bifidobacterium was greater in HBM than both formula groups at six mos (q<0.05) and only greater than the SF group at 12 mos of age (p<0.05). The relative abundance of Veillonella was greater in HBM than SF at six mos (q<0.05) and greater than both formula groups at 12 mos of age (p<0.05). Other dietary differences in the relative abundance of genera at six mos did not persist at 12 mos of age.
Conclusions: Infants fed soy formula show major differences in microbiota composition compared to infants fed HBM or MF and the differences in relative abundance of very few taxa at six mos persisted at 12 mos. Future studies will determine how specific components of HBM and formula modulate gut microbiota colonization.
USDA 6251-51000-007-05 and NIH P20GM121293.
Arkansas Children’s Nutrition Center -and- Arkansas Children’s Research Institute
Little Rock, Arkansas