Prebiotics are defined as non-digestible food ingredients that selectively stimulate the growth of beneficial gut bacteria, thereby improving host health. Recent research highlights their role in various health conditions, including colorectal cancer, neurological disorders, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. The International Scientific Association for Probiotics and Prebiotics (ISAPP) updated the definition to emphasize substrates that are selectively utilized by host microorganisms to confer health benefits. A literature review identified five main clusters of research: pathologies, metabolic conditions, structure and use in food, immunomodulation, and effect on gut microbiota. Prebiotics have shown potential in reducing inflammation, improving gut microbiota composition, and modulating immune responses. They also influence metabolic processes, such as reducing blood lipid levels and improving insulin resistance. Prebiotics can be found in various food sources and may also be administered directly to other microbially colonized sites. Studies indicate that prebiotics can improve cognitive functions, reduce stress, and alleviate symptoms of autism and schizophrenia. They have also been shown to benefit inflammatory bowel disease, irritable bowel syndrome, and enteric syndrome by modulating gut microbiota and reducing inflammation. In obesity and diabetes, prebiotics may help regulate gut microbiota, improve glucose tolerance, and reduce inflammation. For metabolic syndrome, prebiotics may help reduce Firmicutes/Bacteroidetes ratio and improve lipid metabolism. Prebiotics also play a role in osteoporosis by improving calcium absorption and bone density. In immunosenescence, prebiotics may help maintain a "youthful" gut microbiota, reducing inflammation and improving immune function. Overall, prebiotics show promise in various health conditions, but further research is needed to clarify their mechanisms and optimize their use.Prebiotics are defined as non-digestible food ingredients that selectively stimulate the growth of beneficial gut bacteria, thereby improving host health. Recent research highlights their role in various health conditions, including colorectal cancer, neurological disorders, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. The International Scientific Association for Probiotics and Prebiotics (ISAPP) updated the definition to emphasize substrates that are selectively utilized by host microorganisms to confer health benefits. A literature review identified five main clusters of research: pathologies, metabolic conditions, structure and use in food, immunomodulation, and effect on gut microbiota. Prebiotics have shown potential in reducing inflammation, improving gut microbiota composition, and modulating immune responses. They also influence metabolic processes, such as reducing blood lipid levels and improving insulin resistance. Prebiotics can be found in various food sources and may also be administered directly to other microbially colonized sites. Studies indicate that prebiotics can improve cognitive functions, reduce stress, and alleviate symptoms of autism and schizophrenia. They have also been shown to benefit inflammatory bowel disease, irritable bowel syndrome, and enteric syndrome by modulating gut microbiota and reducing inflammation. In obesity and diabetes, prebiotics may help regulate gut microbiota, improve glucose tolerance, and reduce inflammation. For metabolic syndrome, prebiotics may help reduce Firmicutes/Bacteroidetes ratio and improve lipid metabolism. Prebiotics also play a role in osteoporosis by improving calcium absorption and bone density. In immunosenescence, prebiotics may help maintain a "youthful" gut microbiota, reducing inflammation and improving immune function. Overall, prebiotics show promise in various health conditions, but further research is needed to clarify their mechanisms and optimize their use.