Thanks to the work of 32 scientists at twelve institutions in seven different countries, a “microbial Pompeii” has been discovered with monumental implications for modern dentists.
Ancient human dental calculus, or plaque, has been recovered from the teeth of 1000 year old skeletons, which preserved bacteria and microscopic food particles.
The research team was able to isolate ancient dietary DNA which was not compromised by the burial environment. Bone quickly loses most of its molecular information when buried, but calculus grows slowly in the mouth and preserves biomolecules by entering the soil at a much more stable rate.
This allowed researchers to study and identify dietary components like vegetables, which normally leaves little trace in the archaeological record. The team also discovered that despite major changes in diet and hygiene, periodontal disease is caused by the same bacteria today as in the past.
Reconstructing the Ancient Oral Microbiome
The multi-national effort was led by the University of Zurich, the University of Copenhagen, and the University of York. Researchers led by Dr. Christina Warinner were given the challenge of analyzing and sorting millions of genetic sequences and reconstructing the complex biology of the ancient oral microbiome.
“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,” says Professor Christian von Mering, an author of the study and Group Director at the SIB Swiss Institute of Bioinformatics, which performed the bioinformatics analysis.
“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,” according to Professor Matthew Collins of the University of York.
Dr. Warinner, of the University of Zurich and the University of Oklahoma, added: “Dental calculus acts both as a long-term reservoir of the oral microbiome and as a trap for dietary and environmental debris. This allows us to investigate health and disease, as well as reconstruct aspects of an individual’s life history and activities. Never before have we been able to retrieve so much information from one small sample.”
The Origins of Periodontal Disease
The most far reaching implications of this study have to do with our understanding of the origins of periodontal disease. Today, more than 10% of the population is affected by periodontal disease. It causes chronic inflammation which often results in tooth and bone loss. Periodontal disease is also linked to many systemic diseases including cardiovascular disease, stroke, pulmonary disease, and type II diabetes.
Dr. Enrico Cappellini of the University of Copenhagen, a senior author of the study, describes the dental calculus analyzed in this study as a kind of “battlefield archaeological site, just at the molecular scale.”
“As we learn more about the evolution of this microbiome in response to migration and changes in diet, health and medicine, I can imagine a future in which most archaeologists regard calculus as more interesting than the teeth themselves,” says Professor Collins.
“The study of ancient microbiomes helps us understand the evolutionary history of human health and disease,” says Professor Frank Rühli, a senior author of the study and Head of the Centre for Evolutionary Medicine at the University of Zürich. “It informs modern medicine.”
Recognizing and treating periodontal disease is as important as ever. Even if you don’t notice any symptoms you may still have some degree of gum disease. So, if you haven’t seen a dentist in the past 6 months, please make an appointment with Dr. Matthews today.