Background & objectives:There is a direct relationship between the presence of beneficial microbiota in the gut, development immune system functions and maintenance homeostasis. Hence, the consumption of foods or supplements with postbiotic components has been characterized as one of the most important strategies to modify the microbiome balance and improve the health status of the host. In this study, the concept of postbiotics and their clinical role in host health has been reviewed. Methods: All articles related to the study subject were searched in the Scopus, PubMed/Medline, ISI Web of Knowledge, and Google Scholar database and studies that examined the effects of postbiotics on diseases were included. Results: According to available evidences, postbiotics do not need the viability in comparison with their parent cells and they exert health effects like live probiotic cells. Also, their preparation and application in various delivery system is affordable, which this highlights the importance of postbiotics from technological, clinical and economic aspects. These compounds have biological activities including immunomodulation, antimicrobial, antiinflammatory, anti-oxidant and anti-proliferation, and they can play an important role in modulating the immune system's performance, improving therapies and reducing their possible side-effects in some cases of gastrointestinal disorders and chronic diseases. Conclusion:The postbiotics as a novel strategy can be used in a wide range of pharmaceutical products for the preventive therapy and improvement of the current therapeutic methods, as well as in food products to delay corruption, increase shelf life, and promote functional foods.