A bifidogenic effect is observed in young infants fed infant formula supplemented with galactooligosaccharide (GOS) and polydextrose (PDX)

Background Prebiotics contribute to healthy gut and immune development in infants by promoting beneficial gut microbiota rich in Bifidobacterium, predominantly B. longum, B. infantis and B. breve. Objective To assess the impact of a GOS/PDX-supplemented infant formula on fecal microbiota. Methods In this double-blind study, 21 to 30-day old healthy term, vaginally delivered infants were randomized to receive Control (Enfamil Lipil®, Mead Johnson Nutrition, CTRL) or Control + GOS/PDX (4 g/L, 1:1 ratio, GP) for 60 d; there was a breastfed (BF) reference group. Stool samples were obtained at baseline and after 30 and 60 d of feeding. Microbiota by fluorescent in situ hybridization (FISH) and quantitative polymerase chain reaction (qPCR) was analyzed by Wilcoxon rank-sum test. Results 230 of 289 infants completed the study (CTRL=81, GP=78, BF=71). Total bifidobacteria by FISH at 30 d was similar among groups and at 60 d lower in CTRL and GP vs. BF (P≤0.049), with it tending to be higher in GP vs. CTRL (P=0.084). By qPCR, bacterial counts at 30 d tended to be higher in GP vs. CTRL for total bifidobacteria (P=0.069) and B. longum (P=0.057); GP was higher vs. CTRL for B. infantis at 30 d and for total bifidobacteria and B. longum at 60 d (P=0.002); at 60 d CTRL, but not GP, was lower than BF for total bifidobacteria and B. longum (P≤0.009) [Table]. Mean ranks of qPCR absolute counts of total bifidobacteria, B. longum, and B infantis at 60 days of feeding.+ Total bifidobacteria B. longum B. infantis BF 119 113 106 CTRL 81ab 83ab 95 GP 109 111 104 + Wilcoxon rank-sum test a CTRL < BF, P≤0.009 b GP > CTRL, P=0.002 Conclusion GOS/PDX added to infant formula has a bifidogenic effect in young infants.