Postmortem microbiome dynamics: Review of forensic microbial clock

Area of Science:

• Forensic Science
• Microbiology
• Ecology

Background:

• Estimating the postmortem interval (PMI) is crucial in forensic science but faces challenges with current physical and microbial markers due to environmental variability.
• Microbial succession, termed the 'microbial clock,' presents a promising alternative for more accurate PMI determination.

Purpose of the Study:

• To review current knowledge on the microbial clock as a tool for estimating PMI.
• To discuss the ecological and practical considerations for developing a reliable microbial clock for forensic applications.

Main Methods:

• Analysis of over 30 peer-reviewed studies on human cadavers and animal models.
• Examination of microbial community changes during decomposition and their temporal correlations.

Main Results:

• Microbial communities exhibit predictable, time-dependent changes during decomposition, both internally and externally.
• Studies on murine, porcine, and human models show strong temporal links between specific microbes and decomposition stages, with potential accuracy within days.
• Organ-specific microbial signatures change predictably over time, offering insights into PMI.

Conclusions:

• Microbial succession is a powerful quantitative tool for determining PMI.
• Further research with diverse datasets and multiple indicators is needed to fully establish the microbial clock for forensic practice.