Postbiotics as Emerging Functional Biotics: Antimicrobial Potential, Production Strategies, and Mechanistic Insights

Abstract

Background: Postbiotics have recently emerged as a promising category of functional biotics derived from microbial fermentation. Unlike probiotics, postbiotics consist of non-viable microbial cells, metabolites, and structural components that exert biological effects without requiring microbial viability. Their improved stability, safety profile, and defined biochemical composition have generated increasing interest for applications in biotechnology, food science, and therapeutic development. Methods: This review systematically analyzed recent literature on postbiotics, focusing on their microbial sources, bioactive components, production strategies, characterization methods, antimicrobial mechanisms, and potential therapeutic applications. Relevant studies were evaluated to summarize current advances in fermentation technologies, downstream processing, and analytical approaches used for postbiotic identification and functional evaluation. Results: Evidence from recent studies indicates that postbiotics contain diverse bioactive compounds, including short-chain fatty acids, bacteriocins, exopolysaccharides, enzymes, peptides, and cell wall fragments. These components contribute to multiple biological effects, particularly antimicrobial activity against pathogenic microorganisms, modulation of host immune responses, improvement of intestinal barrier function, and regulation of metabolic pathways. Compared with live probiotics, postbiotics demonstrate greater physicochemical stability, longer shelf life, and reduced risk of infection, making them more suitable for incorporation into pharmaceutical formulations, functional foods, and cosmetic products. Conclusion: Postbiotics represent a promising next-generation functional biotic with significant antimicrobial and therapeutic potential. Advances in microbial fermentation, molecular characterization, and precision bioprocessing are expected to facilitate the development of standardized postbiotic formulations for biomedical and industrial applications.