Following an application from Synbiotec S.r.l., submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Italy, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to SYNBIO®, a combination of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502®, and maintenance of normal defecation. The Panel considers that the food, SYNBIO®, which is the subject of the health claim, is sufficiently characterised. Maintenance of normal defecation is a beneficial physiological effect. The applicant identified three human intervention studies which investigated the effect of SYNBIO® on outcome measures (i.e. frequency of defecations, faecal bulk and stool consistency) related to the claimed effect. The Panel notes that no evidence was provided that the tools used to assess changes in bowel habits in response to an intervention were valid. Therefore, no conclusions could be drawn from these studies for the scientific substantiation of a claim on SYNBIO® and maintenance of normal defecation. In the absence of evidence for an effect of SYNBIO® on the maintenance of normal defecation in humans, studies which investigated the presence of L. rhamnosus IMC 501® and L. paracasei IMC 502® in the faeces of participants who consumed foods enriched with these strains were not considered by the Panel. The Panel concludes that a cause and effect relationship has not been established between the consumption of SYNBIO® and maintenance of normal defecation.