The PVTGs (Particularly Vulnerable Tribal Groups) of India are believed to be the descendants of some of the earliest human populations to have migrated to India. However, due to centuries of isolation and limited interaction with other communities, they remain a relatively understudied group in regards to their genetic ancestry. In recent years, research has shown that the dental microbiome, specifically dental calculus, can be used as a rich source of information about an individual's ancestry using bacterial taxa as a marker. Broadly, such a study can be conducted at the population level.
Dental calculus accumulates over an individual’s lifetime and can stay intact even after death, under suitable conditions, and thus preserve sequences of habitation by bacteria. Extraction of dental calculus is one of the easily accessible mediums of genetic markers. Such a research shall involve the collection of dental calculus samples from individuals belonging to various PVTGs across the country, both living and deceased individuals, with the latter involving osteoarchaeological excavations. The dental calculus samples can then be analysed using next-generation sequencing techniques to identify the bacterial taxa present in the microbiome. These datasets can be compared with various existing datasets of dental microbiomes from other populations, within India and elsewhere, in order to identify similarities and differences among them and make informed conclusions regarding the history of the PVTGs.
The results can have significant implications towards our understanding of the genetic ancestry of the PVTGs, early human migrations, and the peopling of the Indian subcontinent. Analysis of dental microbiome can similarly be used for other indigenous and isolated populations, around the world, whose ancestries are less known. Thus, dental, and other oral, microbiomes can become a key tool in molecular anthropology in the future.
