The present invention relates to a nutritional composition comprising an oligosaccharide mixture, said oligosaccharide mixture comprising at least one N-acetylated oligosaccharide, one galacto-oligosaccharide and one sialylated oligosaccharide for use in preventing and/or treating allergy symptomsin an infant or a young child, by increasing SFCA production, in particular colonic acetate, propionate and/or butyrate,in said infant or young children.