Probiotics are living microorganisms supplemented in food that provide excellent health benefits, as they boost the resistance mechanisms against pathogens by maintaining intestinal microbiota homeostasis. Consumption of probiotics has shown beneficial effects on different organs in human hosts; therefore probiotic-based therapeutics is an emerging theme of great interest. In recent years, many reports have been published to elucidate the importance and functional aspects of probiotics in the improvement of human health. In this study we searched PubMed, Science Direct, Scopus, and Google Scholar databases to evaluate the role of probiotics in inflammatory bowel diseases, mental disorders, colon cancer, obesity management, and oral health issues. The full text of articles on animal and human studies in the last 10–15 years were retrieved, and data related to the significance and effectiveness of probiotics are discussed in this chapter. Furthermore, the regulatory framework of probiotics in some countries is presented.