 Gut microbiota plays a crucial role in human health, but current traditional medicines can only relieve symptoms and cause side effects like disturbances in the gut microbiota. Probiotics, prebiotics, and postbiotics have been shown to prevent and treat various diseases, but their clinical application is limited due to being dietary supplements rather than medicines. This review analyzes their effectiveness and mechanisms based on animal models and clinical trials, and discusses the challenges and prospects of their clinical application in maintaining health and treating diseases.