Development of an Ex Vivo Skin Model for Quantitative Recovery and Preservation of Donor-Specific Human Microbiota
Background Understanding how human skin interacts with its resident microbiota requires ex vivo models capable of sustaining both the complexity and the individuality of native microbial communities. Many available systems quickly lose this structure or support only simplified assemblages, limiting their relevance for ecological and functional studies. We evaluated whether a new ex vivo human skin explant model (Perfex) could host complete, donor-derived microbiota and preserve their ecological and immunological characteristics under conditions designed to approximate the skin surface. Results Skin swabs collected from healthy volunteers yielded diverse bacterial communities that included both aerobic and anaerobic populations, with a substantial number of viable cells. After transfer onto Perfex explants, a measurable proportion of the viable microbiota persisted over the 48-hour incubation. Community analyses showed that the overall microbial structure was well conserved following transfer. Alpha diversity remained stable, and beta diversity analyses consistently revealed strong donor-specific clustering. Post-transfer communities aligned closely with their corresponding in vivo samples, demonstrating that the individuality of each microbiota was largely maintained. Key cutaneous genera such as Cutibacterium, Staphylococcus, Corynebacterium, Streptococcus and Roseomonas remained dominant, with minimal taxonomic drift. The model did not favour any specific group, suggesting that the explant environment provides balanced conditions suitable for supporting a broad spectrum of commensal taxa, including those sensitive to environmental shifts. Throughout the experiment, the skin explants retained normal tissue architecture. Contact with the transplanted microbiota induced a moderate but clear activation of innate defence pathways, reflected in increased expression of antimicrobial and microbial-recognition markers (including hBD2 and TLR2), whereas inflammatory signaling such as TNF-a remained low. This pattern is consistent with a controlled and physiological interaction between skin tissue and commensal microorganisms. Conclusions The Perfex model enables robust transfer and short-term maintenance of complex, donor-specific skin microbiota while preserving tissue viability and balanced innate immune activation. By maintaining both community structure and inter-individual specificity, this ex vivo system offers a reliable platform for studying cutaneous microbial ecology, modelling dysbiosis in controlled conditions, and evaluating microbiome-focused dermatological or cosmetic strategies.