PurposeBreastfeeding is the best way to feed all infants, but not all infants can be (exclusively) breastfed. Cow's milk based infant formula is the second choice infant feeding.MethodsThe safety of a new synbiotic infant formula, supplemented with Bifidobacterium lactis and fructo-oligosaccharides, with lactose and a whey/casein 60/40 protein ratio was tested in 280 infants during 3 months.ResultsThe median age of the infants at inclusion was 0.89 months. Weight evolution was in accordance with the World Health Organization growth charts for exclusive breastfed infants. The evolution of all anthropometric parameters (weight-for-length z score and body mass index-for-age z score) was within the normal range. The incidence of functional constipation (3.2%), daily regurgitation (10.9%), infantile crying and colic (10.5%) were all significantly lower than the reported median prevalence for a similar age according to literature (median value of 7.8% for functional constipation, 26.7% for regurgitation, 17.7% for infantile colic).ConclusionThe new synbiotic infant starter formula was safe, resulted in normal growth and was well tolerated. Functional gastro-intestinal manifestations (functional constipation, regurgitation and colic) were significantly lower than reported in literature. Synbiotics (Bifidobacterium lactis and fructo-oligosaccharides) in cow's milk based infant formula bring the second choice infant feeding, formula, closer to the golden standard, exclusive breastfeeding.