Forensic analysis of environmental and skin microbiome differences in college dormitories based on 16 S rRNA.

Microbial traces shed by humans into the built environment offer a novel tool for forensic science, providing potential links between an individual and a specific location. With their standardized designs, university dormitories provide an ideal model to explore the microbial link between individuals and their living spaces. We employed 16 S rRNA gene sequencing to characterize 128 samples from six dormitories, aiming to determine if microbial communities could link individuals to their living spaces. Our analysis revealed that while phylum-level composition was broadly conserved, microbial communities diverged markedly at the genus level. Community composition was significantly shaped by occupant biological sex and room occupancy, with alpha-diversity decreasing as occupancy increased. SourceTracker analysis identified environmental surfaces as a primary reservoir for the residents’ skin microbiome, while the contribution of unknown sources escalated in more crowded rooms. Critically, random forest models demonstrated high predictive power, accurately classifying occupant biological sex (92.11% test accuracy), room occupancy (78.38%), and the specific dormitory of origin (83.33%). These findings underscore the spatial specificity of microbial signatures in shared living spaces, establishing a strong empirical basis for exploring their application in forensic science to link an individual to their recent environment.