The present invention relates to a nutritional composition comprising at least two different beta-galacto-oligosaccharides (BGOS) A and B wherein the majority of linkages between two galactose residues in BGOS A are beta 1,4 and/or beta 1,6, and the majority of linkages between two galactose residues in BGOS B are beta 1,3. Such mixtures show superior effects on the immune system and are particularly suitable for infant nutrition.
