Findings and methodology are presented for a large-scale assessment of the human microbiome after death, so as to determine whether postmortem microbial communities persist after host death.
The study consisted of a large-scale survey of death cases that represented a predominantly urban population in the industrial Midwest. Microbial taxonomic profiles from 188 routine death investigations were generated from targeted amplicon sequencing (16s ribosomal RNA gene). Predicted functional profiles were also determined with the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States pipeline to estimate community gene content based on available sequenced amplicons. The combined composition and predicted functional profiles were modeled in relation to anatomic sampling location, population demographics, and estimated postmortem interval. The study found strong niche differentiation of anatomic habitat and microbial community turnover based on topographical distribution. Microbial community stability was documented up to 2 days after death. There was a positive relationship between cell motility and time since host death. There was evidence that microbial biodiversity is a predictor of antemortem host health condition. These findings improve understanding of postmortem host microbiota dynamics and provide a robust dataset to test the postmortem microbiome as a tool for assessing heath conditions in living populations. 3 figures, 1 table, and 87 references