Abstract: Supplementation of infant formula with ingredients potentially able to manage, in a way positive for the host, the gut microbiota of infants, is nowadays widely used by infant food producers. The impact of this class of compounds, named prebiotics, on gut microbiota composition, was initially measured on the enrichment of Bifidobacterium and Lactobacillus spp., but the use of culture-independent analytical techniques has allowed to establish that a larger number of intestinal microorganisms are affected by the ingestion of prebiotics. However, despite a relevant number of scientific publications, actually there is no consensus on the amount of prebiotics to be administered daily, the potentially different actions exerted by prebiotics which differ in biochemical structures, as well as the impact of different percentages of the same prebiotics when used in mixtures and/or combination. This paper is aimed to critically review the available data on the use of prebiotics in infant formula, with special attention paid to identify a link between, the dosage used, the mixture composition and the observed outcomes, keeping in mind the influences in nutrition quality and growth influence.