Unveiling the Forensic Potential of Oral and Nasal Microbiota in Post-Mortem Interval Estimation

作者：Ji Chen, Wei Qi, Fengtang Yang, Y Liu, Yurong Zhao, Han Zhang, Xin Huang, Jianye Zeng, Xiang Wang, Suhua Zhang · 发表于：International Journal of Molecular Sciences · 年份：2025 · DOI：10.3390/ijms26073432 · 被引用次数：6 · 研究领域：Gut microbiota and health、Forensic Entomology and Diptera Studies、Bacterial Identification and Susceptibility Testing

Microbiota have emerged as a promising tool for estimating the post-mortem interval (PMI) in forensic investigations. The role of oral and nasal microbiota in cadaver decomposition is crucial; however, their distribution across human cadavers at different PMIs remains underexplored. In this study, we collected 88 swab samples from the oral and nasal cavities of 10 healthy volunteers and 34 human cadavers. Using 16S rRNA gene sequencing, we conducted comprehensive analyses of the alpha diversity, beta diversity, and relative abundance distribution to characterize the microbial communities in both healthy individuals and cadavers at varying PMIs and under different freezing conditions. Random forest models identified Firmicutes, Proteobacteria, Bacteroidota, Actinobacteriota, and Fusobacteriota as potential PMI-associated biomarkers at the phylum level for both the oral and nasal groups, along with genus-level biomarkers specific to each group. These biomarkers exhibited nonlinear changes over increasing PMI, with turning points observed on days 5, 12, and 22. The random forest inference models demonstrated that oral biomarkers at both the genus and phylum levels achieved the lowest mean absolute error (MAE) values in the training dataset (MAE = 2.16 days) and the testing dataset (MAE = 5.14 days). Additionally, freezing had minimal impact on the overall phylum-level microbial composition, although it did affect the relative abundance of certain phyla. At the genus level, signi...