Dental calculus, or tartar, present in a 1000-year-old skeleton has helped researchers find “microbial Pompeii.”
The study showed that the germs that affected our ancestors continue to cause cavities in modern humans. Interestingly, the study also shows that microbes had the same genetic signature centuries before the arrival of antibiotics. Their research shows that dental calculus contains valuable information about microbial life affecting early humans.
About 32 scientists at twelve institutions in seven countries participated in the current study. They analyzed the DNA of the ancient oral cavity to learn more about ancient humans’ lifestyle, health and eating habits.
According to researchers, oral cavities preserve bio-molecules better than bones. Dental calculus is preserved in the mouth and takes longer to reach the soil, meaning that the tartar can be used to study ancient microbial life.
“Dental calculus is a window into the past and may well turn out to be one of the best-preserved records of human-associated microbes,” said Professor Christian von Mering, an author of the study and Group Director at the SIB Swiss Institute of Bioinformaticsk. “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.”
For the study, researchers analyzed fossilized dental plaque present on the teeth of a middle-aged man from the medieval site of Dalheim, Germany, ca. AD 1100, according to a news release by the University of York.
The team used shotgun DNA sequencing to reconstruct the genome of a pathogen present in the ancient tartar. They also studied the dietary biomolecules from the dental calculus.
A related study had earlier documented the rise of dental cavities and had found that they were linked with the rise of agriculture. A recent study by researchers at Oxford and their colleagues,found that dental problems existed even when humans were hunter-gatherers and followed a paleo diet.
“The study of ancient microbiomes helps us understand the evolutionary history of human health and disease,” said Prof. Frank Rühli, a senior author of the study and Head of the Centre for Evolutionary Medicine at the University of Zürich, according to a news release. “It informs modern medicine.”
The study included researchers from University of York and is published in the journal Nature Genetics.