Microbial communities have potential evidential utility for forensic applications. However, bioinformatic analysis of high-throughput sequencing data varies widely among laboratories and can potentially affect downstream forensic analyses and data interpretations. To illustrate the importance of standardizing methodology, we compared analyses of postmortem microbiome samples using several bioinformatic pipelines, while varying minimum library size or the minimum number of sequences per sample, and sample size. Using the same input sequence data, we found that pipeline significantly affected the microbial communities. Increasing minimum library size and sample size increased the number of low abundant and infrequent taxa detected. Our results show that bioinformatic pipeline and parameter choice significantly affect the resulting microbial communities, which is important for forensic applications. One such forensic application is the potential postmortem reflection of manner of death (MOD) and cause of death (COD). Microbial community metrics have linked the postmortem microbiome with antemortem health status. To further explore this association, we demonstrated that postmortem microbiomes could differentiate beta-dispersion among M/COD, especially for cardiovascular disease and drug-related deaths. Beta-dispersion associated with M/COD has potential forensic utility to aid certifiers of death by providing additional evidence for death determination. Additional supplemental files including tables of raw data and additional statistical tests are available in supplemental files online, denoted in the text as table 'S'.
Read
