Postbiotics: an insightful review of the latest category in functional biotics

Postbiotics have recently emerged as one of the latest functional food products due to the ever-evolving landscape for microbiome-targeted health interventions. Postbiotics, along with other functional biotics, viz., probiotics, prebiotics and synbiotics, confer their health benefits mainly via the modulation of the gut microbiota. Postbiotics are considered more promising than probiotics as they elicit similar effects, despite being inactivated, thus relegating concerns of strain activity and stability that have been raised about probiotics. This review attempts to provide critical insights into postbiotics by firstly revising its definition to create a streamlined framework for further discourse on the interplay between postbiotics, nutrition, microbiota, and health. Similarly, this review establishes the nexus between postbiotics and probiotics while highlighting that postbiotics can also be derived from other microbes apart from lactobacilli such as yeasts and fungi. Furthermore, an overview of the extraction and production of postbiotics are presented as well as the biochemistry of short-chain fatty acids, enzymes, peptides, polysaccharides, peptidoglycans and teichoic acids, which have all been identified as postbiotic components. Finally, their bioactivities (antioxidant, anti-inflammatory, antidiabetic, immunomodulatory, anti-hypertensive, antimicrobial) and the patent landscape of postbiotics are evaluated to promote its innovative applications in the food, veterinary, pharmaceutical and cosmetic industries. Having identified major gaps and areas of improvement, it is believed that this critical review will serve as a guide in the increasing effort to advance the industrial potential of postbiotics.