Microbial Signatures in the Oral Microbiome as a Potential Tool in Forensic Human Identification

The oral cavity has been classified as an area with one of the largest and diverse microbial communities in the human body. The constituents of this community have been shown to vary among individuals as they are influenced by various factors. This variation in individuals presents new implications for forensic investigations regarding human identification as the oral microbiome can potentially be used as a new type of evidence. However, significant gaps in knowledge concerning how factors such as age, sex, geographical provenience, etc. affect the oral microbiome is still largely unknown. Thus, the aim of this study is to add to existing knowledge by examination of the oral microbiome of individuals and their lifestyles. For this study, 50 individuals residing within Italy donated oral swab samples and provided information regarding their diet, lifestyle, health status, antibiotic use and other personal data. Skin swabs from 11 of the 50 individuals were also analyzed and compared to the oral swabs from the same donors. All analyses were done through metabarcoding of the 16S rRNA region of DNA extracted from the samples. The results showed the presence of a core microbiome within all the samples. It also indicated microbial signatures associated with a specific individual or certain grouping conditions or habits. This has significant implications for forensic investigations for which the ability to differentiate is essential. This research outlines the potential use of oral microbiome signatures in forensic human identification and in providing investigative information regarding the lifestyle of the host donor.