Effects of Term Infant Formula Supplemented with Oligofructose on Intestinal Microbiota Composition, Diversity, and Metabolic Activity

Abstract

Background and AimsPrebiotic oligosaccharides in breastmilk may promote infants’ digestive health. We evaluated the effects of a term infant formula with oligofructose (OF) on infant growth, fecal microbiota and microbial metabolism.MethodsData from an 8‐week randomized controlled trial of healthy Filipino infants was used to compare growth and fecal microbiota outcomes in a subset of infants fed high sn‐2 palmitate formula (F1) or an identical formula with 5 g/L OF (F2), and a non‐randomized breastfed group (BF). Growth was measured at baseline, week 4, and week 8 (n per group 73–75). Stool samples were collected at baseline and week 8. Baseline‐adjusted group comparisons based on wet weight stool were performed in the per‐protocol population at week 8 (n per group 30–37), including fecal bacteria group counts (FISH), organic acids (HPLC) and pH as well as pathogen counts (qPCR, n per group 26–27). Fecal bacteria abundance and diversity (pyrosequencing, n per group 9–11) were assessed at week 8.ResultsWeight, length and head circumference were similar in all groups at each visit and together with z‐scores supported clinically adequate growth. From baseline to week 8, infants fed F2 (vs. F1) had a smaller increase in the Clostridia group (mean difference ± SE; 0.41 ± 0.16 vs. 0.91 ± 0.18, p=0.015) and a greater decrease in the Enterobacteriaceae group (−0.29 ± 0.13 vs. −0.06 ± 0.11, p=0.037). Infants fed F2 (vs. F1) had significantly different changes from baseline in pH (p<0.0001), lactate (p<0.0001), propionate (p=0.0057), butyrate (p=0.0139), and total organic acids (p=0.0148). At week 8, infants receiving F2 did not differ from BF in pH, or in concentrations of lactate, butyrate, the Lactobacilli/Enterococci group, the Clostridia group, C. perfringens species, or E. coli, EPEC species. In the pyrosequencing analysis, the F2 group had less of the Peptostreptococcaceae group vs. F1 (p=0.047) at week 8 and was not different from the BF infants, and bifidobacteria strongly dominated the microbiota of infants receiving F2 (median=92%), similar to BF infants (90%). Insufficient power limited some analyses. The F2 group (vs. F1) had a numerically smaller increase from baseline in C. difficile and E. coli, EPEC species. The average weighted UniFrac distance (a measure of phylogenetic distance between bacterial communities) was smaller between the F2 group vs. BF than between the F1 group vs. BF. Finally, bacterial communities from the F2 group had a smaller Shannon diversity index vs. F1, suggesting fewer and less evenly distributed species, and closer to the diversity index of the BF infants.ConclusionInfants grew similarly in all groups. Term infant formula supplemented with 5g/L OF inhibited growth of potentially pathogenic fecal bacteria, lowered pH and shifted the organic acid profile closer to breastfed infants vs. formula without OF. After 8 weeks of feeding, the fecal microbiota composition and microbial metabolism patterns of infants receiving 5 g/L OF were closer to those of breastfed infants.Support or Funding Information This study was sponsored by Wyeth Nutrition, a Nestlé business. The infant formula evaluated in this study was a Wyeth Nutrition product and was provided free of charge.