The study primarily aimed to evaluate the effects of long-term supplementation of an infant formula with a mixture of short and long chain inulin-type oligosaccharides on immunological-health related outcomes, as well as on gastrointestinal function and well-being in infants during the first year of life. Effects on infant growth, tolerance and on the composition of fecal microbiota were further objectives of this study. The study was conducted as a multicenter, randomised, double-blind, placebo-controlled study in healthy term infants. The two groups of the study are product group (standard infant formula supplemented with inulin-type fructans) and control group (non-supplemented standard infant formula).