Postbiotics at the interface of microbial biotechnology and therapeutics: industrial production, functional mechanisms, and clinical potentials

Postbiotics, defined as preparations containing inactivated microbial cells, cell fragments, and bioactive metabolites are increasingly recognized as next-generation functional ingredients owing to their superior safety, stability, and regulatory flexibility compared with live probiotics. Their capacity to modulate immune responses, exert antimicrobial effects, enhance metabolic homeostasis, and strengthen gut-barrier integrity without the risks associated with microbial viability or translocation makes them highly suitable for applications in foods, pharmaceuticals, animal feed, and aquaculture systems. Nevertheless, despite rapid commercial expansion, the scientific foundations and industrial processes required for consistent postbiotic production remain poorly integrated, with limited standardization across strain selection, inactivation strategies, and analytical quality metrics. This review highlights recent developments in targeted strain selection, controlled fermentation strategies, downstream processing innovations, and emerging thermal and non-thermal inactivation methods designed to preserve essential structural and metabolic components. It further examines downstream stabilization approaches such as microencapsulation, freeze-drying, and advanced filtration techniques that enhance product functionality and shelf stability. In addition, the review consolidates the expanding portfolio of commercial postbiotic formulations, outlines the microbial species employed, and summarizes the evidence supporting their health benefits across diverse application sectors. Particular emphasis is placed on technological innovations, including precision inactivation tools and multi-omics-driven characterization methods, which are progressively transforming postbiotics from conceptual laboratory entities into scalable industrial solutions. The review also highlights persistent challenges related to process standardization, compositional consistency, and global regulatory alignment, and proposes a structured framework to guide future research and product development. Overall, this work provides an integrated and future-oriented perspective intended to support researchers, industry stakeholders, and regulatory agencies in advancing the science, technology, and commercialization of safe, stable, and efficacious postbiotic products.