Abstract
'Probiotics' and 'prebiotics' by definition should have health benefits. Health claims on microorganisms proposed as probiotics and probiotic stimulating agents (prebiotics) suggest that there is a relationship between the specific food and maintaining good health or that the food can reduce the risk of a disease. The Health Claim Regulation in European Union aims at a level consumer protection. Thereby, health claim assessment focuses on defining the probiotics and prebiotics, assessing the health relationship and evaluating studies with emphasis on controlled human intervention studies. The challenges include the focus of claims for healthy populations while most intervention studies with probiotics and prebiotics have been conducted in patients or subjects at risk of specific diseases. Another challenge is the risk reduction claim, which requires demonstrated changes in biomarkers that are generally accepted as indicators of disease risk. Existing assessment opinions from EFSA illustrate the need for further research for probiotics and prebiotics in the future.