The paper provides an updated overview of the health effects of prebiotics, a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of specific bacteria in the colon. The definition of prebiotics has evolved over time, with the latest consensus from the International Scientific Association for Probiotics and Prebiotics (ISAPP) defining prebiotics as substrates selectively utilized by host microorganisms, conferring health benefits. The paper reviews the current state of knowledge on prebiotics, focusing on seven key conditions: colorectal cancer, neurological or psychiatric conditions, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. A literature search covering the period 2012-2023 identified 2000 articles, which were analyzed using VosViewer to identify five main clusters: pathologies, metabolic conditions, structure and use in food, immunomodulation, and effect on gut microbiota. The review highlights the potential of prebiotics in improving various health outcomes, including reducing inflammation, modulating gut microbiota, and enhancing cognitive functions. The paper also discusses the challenges and limitations in conducting robust clinical trials, emphasizing the need for standardized protocols and further research to fully understand the mechanisms and pathways involved in prebiotic actions.The paper provides an updated overview of the health effects of prebiotics, a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of specific bacteria in the colon. The definition of prebiotics has evolved over time, with the latest consensus from the International Scientific Association for Probiotics and Prebiotics (ISAPP) defining prebiotics as substrates selectively utilized by host microorganisms, conferring health benefits. The paper reviews the current state of knowledge on prebiotics, focusing on seven key conditions: colorectal cancer, neurological or psychiatric conditions, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. A literature search covering the period 2012-2023 identified 2000 articles, which were analyzed using VosViewer to identify five main clusters: pathologies, metabolic conditions, structure and use in food, immunomodulation, and effect on gut microbiota. The review highlights the potential of prebiotics in improving various health outcomes, including reducing inflammation, modulating gut microbiota, and enhancing cognitive functions. The paper also discusses the challenges and limitations in conducting robust clinical trials, emphasizing the need for standardized protocols and further research to fully understand the mechanisms and pathways involved in prebiotic actions.