16S rRNA, metagenomic, and metatranscriptomic analysis of the human hard palate following death

The oral microbiomes of three human donors was sampled over the course of decomposition. Swabbed samples were taken from the hard palates of the donors for 16S rRNA, metagenomic, and metatranscriptomic analyses as well as culturing of bacteria. All donors were elderly and died from natural causes with a male sampled 7 times and two females sampled 5 times each. The study took place in spring and temperature was relatively cool at the site the donors were placed into, the Forensic Osteology Research Station (FOREST) in Cullowhee, NC, USA. Results showed high diversity of prokaryotic and eukaryotic groups with the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes in high numbers for the bacteria over time. Arthropoda, Streptophyta, and Ascomycota were common in the samples, especially later in decomposition as assessed by metagenomics and metatranscriptomics.