Food is the essential need of human life and has nutrients that support growth and health. Gastrointestinal tract microbiota involves valuable microorganisms that develop therapeutic effects and are characterized as probiotics. The investigations on appropriate probiotic strains have led to the characterization of specific metabolic byproducts of probiotics named postbiotics. The probiotics must maintain their survival against inappropriate lethal conditions of the processing, storage, distribution, preparation, and digestion system so that they can exhibit their most health effects. Conversely, probiotic metabolites (postbiotics) have successfully overcome these unfavorable conditions and may be an appropriate alternative to probiotics. Due to their specific chemical structure, safe profile, long shelf-life, and the fact that they contain various signaling molecules, postbiotics may have anti-inflammatory, immunomodulatory, antihypertensive properties, inhibiting abnormal cell proliferation and antioxidative activities. Consequently, present scientific literature approves that postbiotics can mimic the fundamental and clinical role of probiotics, and due to their unique characteristics, they can be applied in an oral delivery system (pharmaceutical/functional foods), as a preharvest food safety hurdle, to promote the shelf-life of food products and develop novel functional foods or/and for developing health benefits, and therapeutic aims. This review addresses the latest postbiotic applications with regard to pharmaceutical formulations and commercial food-based products. Potential postbiotic applications in the promotion of host health status, prevention of disease, and complementary treatment are also reviewed.

The occurrence of colorectal cancer (CRC) has been rising expeditiously and anticipated that 2.4 million new occasions of CRC will be detected yearly around the world until the year 2035. Due to some side-effects and complications of conventional CRC therapies, bioactive components such as microbial-derived biomolecules (postbiotics) have been attaining great significance by researchers for adjuvant therapy in CRC patients. The term ‘postbiotics’ encompasses an extensive range of complex micro- and macro-molecules (<50, 50–100, and 100< kDa) such as inactivated microbial cells, cell fractions or metabolites, which confer various physiological health benefits to the host when administered in adequate amounts. Postbiotics modulate the composition of the gut microbiota and the functionality of the immune system, as well as promote the CRC treatment effectiveness and reduces its side-effects in CRC patients due to possessing anti-oxidant, anti-proliferative, anti-inflammatory, and anti-cancer activities. Presently scientific literature confirms that postbiotics with their unique characteristics in terms of clinical (safe origin), technological (stability), and economic (low production costs) aspects can be used as promising tools for both prevent and adjuvant treat strategies in CRC patients without any serious undesirable side-effects. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the prevention and treatment of CRC.

In recent decades, functional foods with ingredients comprising probiotics, prebiotics and postbiotics have been gaining a lot of attention from scientists. Probiotics and postbiotics are usually applied in pharmaceutical formulations and/or commercial food-based products. These bioactive agents can be associated with host eukaryotic cells and have a key role in maintaining and restoring host health. The review describes the concept of postbiotics, their quality control and potential applications in pharmaceutical formulations and commercial food-based products for health promotion, prevention of disease and complementary treatment. Despite the effectiveness of probiotic products, researchers have introduced the concept of postbiotic to optimize their beneficial effects as well as to meet the needs of consumers to provide a safe product. The finding of recent studies suggests that postbiotics might be appropriate alternative agents for live probiotic cells and can be applied in medical, veterinary and food practice to prevent and to treat some diseases, promote animal health status and develop functional foods. Presently scientific literature confirms that postbiotics, as potential alternative agents, may have superiority in terms of safety relative to their parent live cells, and due to their unique characteristics in terms of clinical, technological and economical aspects, can be applied as promising tools in the drug and food industry for developing health benefits, and therapeutic aims.

During the last two decades, the prevalence and severity of clinical appearances of food allergy (FA) have a significant rise. FA derives from a breakdown of immune tolerance. In recent year’s clinical evidence have shown that the probiotics have significant influences on FA by improving the immune tolerance. Besides, postbiotics due to their unique characteristics (safe profile, more shelf life, resistance to mammalian enzymes and stable to digestive system conditions), may have safety superiority against their parent live cells and as a novel strategy can be applied for improvement immune tolerance and treatment of FA without any undesirable side-effects or human opportunistic infections, particularly in infants and pediatrics.

Postbiotics as novel health-promoting ingredients in functional foods

According to outcomes from clinical studies, an intricate relationship occurs between the beneficial microbiota, gut homeostasis, and the host’s health status. Numerous studies have confirmed the health-promoting effects of probiotics, particularly in gastrointestinal diseases. On the other hand, the safety issues regarding the consumption of some probiotics are still a matter of debate, thus to overcome the problems related to the application of live probiotic cells in terms of clinical, technological, and economic aspects, microbial-derived biomolecules (postbiotics) were introducing as a potential alternative agent. Presently scientific literature confirms that the postbiotic components can be used as promising tools for both prevention and treatment strategies in gastrointestinal disorders with less undesirable side-effects, particularly in infants and children. Future head-to-head trials are required to distinguish appropriate strains of parent cells, optimal dosages of postbiotics, and assessment of the cost-effectiveness of postbiotics compared to alternative drugs. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the treatment of some important gastrointestinal disorders.