New prebiotic blend of polydextrose and galacto-oligosaccharides has a bifidogenic effect in young infants.

OBJECTIVE: The aim of the study was to evaluate the effect of infant formula with polydextrose (PDX) and galacto-oligosaccharides (GOS) on fecal microbiota and secretory IgA (sIgA).

MATERIALS AND METHODS: In the present double-blind, randomized study, term infants received control (Enfamil Lipil) or the same formula with PDX/GOS (4 g/L, 1:1 ratio; PDX/GOS) for 60 days; a reference breast-fed group was included. Formula intake, tolerance, and stool characteristics were collected via electronic diary and analyzed by repeated measures analysis of variance. Anthropometric measurements and stool samples were obtained at baseline and after 30 and 60 days of feeding. Fecal sIgA was measured by enzyme-linked immunosorbent assay and fecal bacteria by fluorescent in situ hybridization and quantitative real-time polymerase chain reaction (qPCR); both were analyzed by Wilcoxon rank sum test.

RESULTS: Two hundred thirty infants completed the study. Infants consuming PDX/GOS had softer stools than control at all times (P < 0.001). Using qPCR, counts in PDX/GOS were closer to the breast-fed group, tended to be higher than control for total bifidobacteria (P = 0.069) and Bifidobacterium longum (P = 0.057) at 30 days, and were significantly higher for total bifidobacteria and B longum at 60 days and B infantis at 30 days (P = 0.002). No significant differences were detected between PDX/GOS and control in changes from baseline to 30 or 60 days for sIgA or total bifidobacteria by fluorescent in situ hybridization or qPCR; however, significantly higher changes from baseline were detected between PDX/GOS and control for B infantis at 30 days and B longum at 60 days (P ≤ 0.035).

CONCLUSIONS: Infant formula with PDX/GOS produces soft stools and a bifidogenic effect closer to breast milk than formula without PDX/GOS.