Probiotics are good bacteria that can be found in dietary supplements and sometimes in dairy products. Probiotics are defined as ”live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” (WHO/FAO 2002, Hill C et al. 2014). An important criterium for qualifying as a true probiotic is that health benefits have been proven in clinical studies. Furthermore, a probiotic product must contain the same bacterial strain(s) and the same dose that was used in the clinical studies.