Washington: Researchers have discovered a ` microbial Pompeii` preserved on the teeth of skeletons around 1,000 years old.
The research team discovered that the ancient human oral cavity carries numerous opportunistic pathogens and that periodontal disease is caused by the same bacteria today as in the past, despite major changes in human diet and hygiene.
The researchers discovered that the ancient human oral microbiome already contained the basic genetic machinery for antibiotic resistance more than eight centuries before the invention of the first therapeutic antibiotics in the 1940s.
Led by the University of Zurich, the University of Copenhagen, and the University of York, this pioneering analysis of ancient oral microbiome ecology and function involved the contributions of 32 scientists at twelve institutions in seven countries.
The research reveals that unlike bone which rapidly loses much of its molecular information when buried, calculus grows slowly in the mouth and enters the soil in a much more stable state helping it to preserve biomolecules.
This enabled the researchers, led by Dr Christina Warinner, to analyse ancient DNA that was not compromised by the burial environment.
They applied shotgun DNA sequencing to dental calculus for the first time. They reconstructed the genome of a major periodontal pathogen and produced possibly the first genetic evidence of dietary biomolecules to be recovered from ancient dental calculus.
Analyzing this wealth of data required overcoming the formidable bioinformatics challenge of sorting and identifying millions of genetic sequences like puzzle pieces in order to reconstruct the complex biology of the ancient oral microbiome.
The research has been published in journal Nature Genetics.