The article provides an overview of the beneficial effects of probiotics, which are living microorganisms that offer health benefits beyond their nutritional value. Probiotics, primarily derived from lactic acid bacteria such as lactobacilli, enterococci, and bifidobacteria, have been widely studied for their specific health effects. Key benefits include relief from lactose intolerance symptoms and shortening of rotavirus diarrhea. The potential of probiotics in treating and preventing atopy is also highlighted. However, many proposed health benefits require further investigation, especially for healthy consumers and beyond the gastrointestinal tract. The definition of probiotics has evolved to include inactivated microorganisms and their cell structures, potentially changing how we view and use them. The choice of microbe for probiotic applications is influenced by various factors, including historical context and the means of administration.The article provides an overview of the beneficial effects of probiotics, which are living microorganisms that offer health benefits beyond their nutritional value. Probiotics, primarily derived from lactic acid bacteria such as lactobacilli, enterococci, and bifidobacteria, have been widely studied for their specific health effects. Key benefits include relief from lactose intolerance symptoms and shortening of rotavirus diarrhea. The potential of probiotics in treating and preventing atopy is also highlighted. However, many proposed health benefits require further investigation, especially for healthy consumers and beyond the gastrointestinal tract. The definition of probiotics has evolved to include inactivated microorganisms and their cell structures, potentially changing how we view and use them. The choice of microbe for probiotic applications is influenced by various factors, including historical context and the means of administration.