"We knew that calculus preserved microscopic particles of food and other debris but the level of preservation of biomolecules is remarkable - a microbiome entombed and preserved in a mineral matrix, a microbial Pompeii," another study researcher, Matthew Collins from the University of York, in England, said in a statement.
With their new study, Warinner and her colleagues are the first to sequence the DNA in ancient dental tartar, using a rapid method known as "shotgun sequencing." The team reconstructed the genome of a major bacterial pathogen and recovered some of the first evidence of food molecules from ancient dental plaque.
The DNA in food found in the plaque matched pigs, sheep, bread wheat and vegetables such as cabbage. The researchers also found starch granules that matched cereals and the pea/bean family.
"Amazingly, it's much the same thing you would find at a German restaurant today," Warinner said.
The skeletons had many years' or decades' worth of plaque built up on their teeth, and many of them showed signs of gum disease and tooth decay. While a few individuals had surprisingly healthy teeth, most of the older adults had lost most or all of their teeth due to wearing, decay or dental disease.