Scientists unlock a microbial Pompeii

An international team of researchers have discovered a microbial Pompeii preserved on the teeth of skeletons around 1,000 years old.

The key to the discovery is the dental calculus (plaque) which preserves bacteria and microscopic particles of food on the surfaces of teeth, effectively creating a mineral tomb for microbiomes.

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. As well as health information, the scientists recovered dietary DNA from ancient dental calculus, allowing the identification of dietary components, such as vegetables, that leave few traces in the archaeological record.

The research published in Nature Genetics 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.