From ferments to fixers: Postbiotics in wound healing

The skin acts as a vital barrier against the environment, and injuries can lead to acute or chronic wounds. Chronic wounds often heal slowly and are more susceptible to infection. Postbiotics, defined as preparations of inactivated microorganisms or their bioactive components, have demonstrated potential to promote wound repair. Compared with live probiotics, postbiotics are safer, more stable, and easier to standardise, while still supporting tissue repair via antimicrobial, anti-inflammatory, antioxidant, and immunomodulatory effects. Compounds such as exopolysaccharides, short-chain fatty acids, antimicrobial peptides, enzymes, vitamins, and cell-free supernatants can enhance fibroblast growth, collagen production, keratinocyte migration, angiogenesis, and immune balance. Postbiotics derived from Lactobacillus , Bifidobacterium , Bacillus , and commensal Staphylococcus species act through multiple signalling pathways. They reduce pro-inflammatory cytokines, promote alternatively activated M2 macrophage polarisation, and facilitate restoration of the skin barrier. Recent developments in hydrogels, nanofibers, and encapsulated delivery systems have improved the stability and availability of postbiotic compounds at wound sites, making them more effective. Despite promising results from preclinical studies and early clinical trials, challenges remain in standardizing production, defining regulatory frameworks, and generating strong clinical evidence. Future studies should focus on identifying key bioactive molecules using advanced omics approaches, developing targeted delivery systems, and evaluating postbiotic therapies in well-designed clinical trials. Overall, postbiotics provide a safe and versatile approach to accelerate wound healing and may serve as an alternative or complement to conventional treatments.