College of Forensic Medicine, Xi'an Jiaotong University, Xi'an, 710061, China.
Xi'an Mental Health Center Hospital, Xi'an, 710061, China.
BMC Microbiol. 2023 Feb 10;23(1):38. doi: 10.1186/s12866-023-02786-0.
Microorganisms distribute and proliferate both inside and outside the body, which are the main mediators of decomposition after death. However, limited information is available on the postmortem microbiota changes of extraintestinal body sites in the early decomposition stage of mammalian corpses.
This study investigated microbial composition variations among different organs and the relationship between microbial communities and time since death over 1 day of decomposition in male C57BL/6 J mice by 16S rRNA sequencing. During 1 day of decomposition, Agrobacterium, Prevotella, Bacillus, and Turicibacter were regarded as time-relevant genera in internal organs at different timepoints. Pathways associated with lipid, amino acid, carbohydrate and terpenoid and polyketide metabolism were significantly enriched at 8 h than that at 0.5 or 4 h. The microbiome compositions and postmortem metabolic pathways differed by time since death, and more importantly, these alterations were organ specific.
The dominant microbes differed by organ, while they tended toward similarity as decomposition progressed. The observed thanatomicrobiome variation by body site provides new knowledge into decomposition ecology and forensic microbiology. Additionally, the microbes detected at 0.5 h in internal organs may inform a new direction for organ transplantation.
微生物在体内外分布和增殖，是死后分解的主要介导者。然而，关于哺乳动物尸体早期分解阶段肠道外部位死后微生物群变化的信息有限。
本研究通过 16S rRNA 测序，研究了雄性 C57BL/6J 小鼠在 1 天分解过程中不同器官之间微生物组成的变化，以及微生物群落与死后时间的关系。在 1 天的分解过程中，Agrobacterium、Prevotella、Bacillus 和 Turicibacter 被认为是不同时间点内部器官中与时间相关的属。与脂质、氨基酸、碳水化合物和萜类及聚酮类代谢相关的途径在 8 小时时明显比在 0.5 小时或 4 小时时丰富。微生物组组成和死后代谢途径随死后时间而变化，更重要的是，这些变化是特定于器官的。
不同器官的优势微生物不同，而随着分解的进行，它们趋于相似。按身体部位观察到的尸体微生物组的变化为分解生态学和法医微生物学提供了新的知识。此外，在内部器官中 0.5 小时检测到的微生物可能为器官移植提供了一个新的方向。
