The post-mortem microbiome: A critical review of microbial succession for estimating post-mortem interval and elucidating cause of death

Abstract

Advances in sequencing technologies have seen an increase of interest in the field of forensic microbiology as applied to PMI estimation, and the nature of microorganisms that may contribute to cause and manner of death. In the present review, we discuss recent progress and gaps in our knowledge of the microbial succession on and in bodies following death (the thanatomicrobiome and epinecrotic microbiome) including their dynamic interactions with environmental microbial communities. The conserved trends over successional development of these communities provide a robust, albeit complex, approach to forensic science that shows potential in furthering Post-Mortem Interval estimates and also perhaps identifying elemental indicators of value for Forensics. Although progress has been made, complex confounding factors (e.g., environmental variables and host-specific characteristics) hamper such applications from forensic microbiome analysis with regard to forensic credibility and courtroom feasibility. In this critical review, we summarize current findings and map out the methodological workflows, major applications, main limitations as well as future prospects of merging microbial ecology with forensics. This inter-disciplinary field integrates microbiology, ecology and forensic science toward a goal of revolutionizing estimation of time since death (and other forensic parameters) through identification of new methods that will replace existing ones. This represents a new avenue; the complex microbial ecosystems are used as "microbial witnesses" to more accurately and with a higher resolution sequence events of the post-mortem interval.