Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to provide a scientific opinion on health claims pursuant to Article 13 of Regulation (EC) No 1924/2006 in the framework of further assessment related to a combination of Lactobacillus acidophilus BCCM/LMG P-18806, Lactobacillus delbrueckii BCCM/LMG P-18805 and Streptococcus thermophilus BCCM/LMG P-18807 and reduction of gastro-intestinal discomfort, decreasing potentially pathogenic gastro-intestinal microorganisms, improved lactose digestion, and reduction in numbers of circulating CD34+ cells. The food constituent that is the subject of the health claim, a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807, is sufficiently characterised. The evidence provided did not establish that the proposed claimed effect, reduction in numbers of circulating CD34+ cells, is a beneficial physiological effect. The claimed effect, reduction of gastro-intestinal discomfort, is a beneficial physiological effect for the general population. The claimed effect, a decrease in potentially pathogenic gastro-intestinal microorganisms, might be a beneficial physiological effect for the general population. The claimed effect, improved lactose digestion, is a beneficial physiological effect for individuals with lactose maldigestion. No human intervention studies were provided from which conclusions could be drawn for the scientific substantiation of the above-mentioned claims. On the basis of the data provided, the Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807 and reduction of gastro-intestinal discomfort, decreasing potentially pathogenic gastro-intestinal microorganisms, and improved lactose digestion.