This Reprint presents recent advances in the functional properties of food source probiotics and their applications in health and food systems. Probiotics, prebiotics, synbiotics, and postbiotics derived from fermented foods and natural food matrices have attracted growing interest due to their roles in modulating gut microbiota, enhancing immune function, and improving metabolic health. The collected articles explore the biological mechanisms of these functional components, their potential in disease prevention, and their use in developing high-quality fermented foods and beverages. In addition, the Reprint addresses the safety evaluation of probiotic strains intended for food applications. Overall, this Reprint highlights current research trends and provides valuable insights for researchers and professionals in food science, nutrition, and microbiome related fields.