Oral Paleomicrobiology: Study of Ancient Oral Microbiome

Background: Paleomicrobiology is a special branch of micropaleontology concerned with the study of bacterial fossils. We have used the term ‘oral paleomicrobiology’, as in this review we have focused on the ancient oral microflora. Recently, dental calculus and dental pulp have been identified as rich sources of ancient microbial DNA. Study of this ancient genetic material opens a new door to the ancient world. This review gives an overview of history of ancient DNA research, various techniques of analyzing ancient DNA in dental calculus and dental pulp, and the implications of the oral paleomicrobiology. Materials and methods: A comprehensive literature search was performed in the following databases—pubmed, medline and google scholar for studies published before 10 April, 2015. The following keywords were used—‘ancient DNA’, ‘ancient oral flora, ‘oral paleomicrobiology’ and ‘oral microbiome’, ‘16S rRNA sequencing’. To obtain additional data, a manual search was performed using the reference lists of selected articles. Result: As a result of literature search, 27 articles were found in pubmed, 12 in google scholar and one in medline. Eight more articles were selected from the reference list of selected articles. Conclusion: The combination of microbiology and paleontology has brought a revolution in the study of human evolution and microbial communities. The naturally well-preserved samples of microbial DNA from dental pulp and microbial colonies trapped in dental calculus are a potential source of microbial genetic material, which will prove invaluable in resolving mysteries of the past. This may be a beginning of a new era of oral paleomicrobiology, which will contribute in our studies about prevention of disease by establishing symbiosis between human beings and their microbiome.