Human clinical trials have shown that probiotics have an effective impact on incidence rate, duration and severity of diseases and their consumption recommended in order to restore balance, to maintain health and enhancing immunity. Probiotic use is associated with a positive effect on gastrointestinal health and decreases its disorders, increase women’s health, improves brain functions, suppresses the occurrence of cold & flu and seasonal, respiratory and dermal allergies, and supports weight loss, oral health and physical activity. From a Practical point of view, probiotics products must contain live and viable cells at the time they consumed and must be non-pathogen and non-toxic. Currently most human probiotics products belong to lactobacilli and bifidobacteria species.