RESUMEN
BACKGROUND & AIMS: The sterile newborn digestive tract is rapidly colonized after birth and feeding type could influence this process. Infant formulas try to mimic the bifidogenic effect of human milk using prebiotic supplementation. The aim of this study was to demonstrate the efficacy, safety and tolerance of a 0.8 g/dL Orafti(®)Synergy1 (oligofructose-enriched inulin) supplemented infant formula during the first 4 months of life. METHODS: In a double-blind, randomized, placebo-controlled and parallel trial, formula fed healthy term newborns were randomized to receive a control (controls) or SYN1 supplemented infant formula (SYN1). Breastfed newborns (BF) were also followed for comparison. Anthropometry, water balance, blood parameters, adverse events, stool frequency and characteristics and faecal microbiota were assessed. RESULTS: A total of 252 formula fed infants were randomized at birth (n = 124 controls, n = 128 SYN1) and 131 BF infants were recruited; after 4 months 68 controls, 63 SYN1 and 57 BF completed the study. SYN1 infants showed a microbiota composition closer to that of BF infants, with a trend towards higher Bifidobacterium cell counts, softer stools and a higher deposition frequency compared to controls. There were no differences between formulas in anthropometry and relevant adverse events, water balance or blood parameters. CONCLUSION: A 0.8 g/dL SYN1-supplemented infant formula during the first 4 months of life is safe and effective, promoting a gut microbiota closer to that of breastfeeding. This clinical trial was registered at Clinicaltrials.gov as Study on Fermentable Carbohydrates in Healthy Infants (number NCT00808756).