Human Oral Microbiome Observed in Bronze Age Skeletal Remains from Tell Leilan, Mesopotamia

Tell Leilan is an extensively researched Bronze Age Mesopotamian archaeological site, located in the northern region of present-day Syria. Skeletal remains curated at St. Lawrence University range in date from 3300 BCE to 1500 BCE and were excavated by the Tell Leilan Archaeology Project based at Yale University. We sought to extract bacterial DNA from the dental calculus (calcified dental plaque) of select individuals to reconstruct a taxonomic profile of their respective oral microbiomes. After thorough decontamination of extracted calculus, decalcification, protein digestion, then DNA extraction and elution in buffer, we were able to identify five samples of adequate quality using NanoDrop 2000 spectrophotometry. Our next step is to prepare sample libraries of single-stranded DNA, and to sequence any present ancient DNA fragments. From there, we will attempt to identify the phylogeny and genetic composition of bacterial species to analyze the microbial composition of oral biofilms from Tell Leilan’s inhabitants.