King Richard III’s oral microbiome hints he had severe gum disease

The oral microbiome of England’s King Richard III has been reconstructed by examining the plaque on his teeth, revealing indications of a disease that could lead to jaw destruction.

In 2012, skeletal remains were uncovered beneath a parking lot in Leicester, UK, on the site of the old Greyfriars church. These remains were believed to belong to Richard III, who died at the battle of Bosworth Field in 1485 and was buried in Leicester, due to injury patterns on the skull that correspond with historical accounts, as well as a curvature of his spine aligning with descriptions of his gait. Genetic testing later verified his identity.

Though his rule lasted a mere two years amidst the Wars of the Roses, Richard’s legacy looms large in English history, with allegations of conspiracy to kill his nephews after imprisoning them in the Tower of London, alongside William Shakespeare’s portrayal of him as a nefarious villain in his famous play.

Details regarding the king’s daily life are scarce. To gain insights, Turi King at the University of Bath, alongside her team, extracted samples of dental calculus, or hardened plaque, from three of his remarkably preserved teeth.

This extraction was crucial as plaque serves as a time capsule, capturing the DNA of microorganisms and remnants of food. “The quantity of DNA obtained from King Richard III’s calculus is among the highest we have documented in archaeological contexts,” they noted in their findings, which revealed over 400 million DNA sequences.

“No one has sequenced ancient DNA to reach 400 million sequences; that’s simply incredible,” states Laura Weyrich from Pennsylvania State University. “This demonstrates that we can likely explore ancient DNA in ways previously thought impossible.”

The researchers identified close to 400 different microbial species from the DNA, with the composition and number mirroring those in well-preserved dental calculus from England, Ireland, Germany, and the Netherlands spanning the last 7000 years, from the Neolithic Period to the present. “It’s indicative that elite individuals carried similar microbial strains [as the general population], despite their lavish lifestyles, extensive travels, and warfare,” explains Weyrich.

Unfortunately, the team could not retrieve enough plant or animal DNA to analyze Richard’s dietary habits. Nevertheless, a prior examination of his bones indicated that in the final two years of his life, he consumed imported wine alongside various game animals, fish, and birds such as swans, herons, and egrets.

However, Weyrich suggests that the microbiome results might vary if the team focused on a specific area of one tooth and compared it to samples from equivalent teeth in other demographics, like those from Germany or the Netherlands. Bacterial diversity also differs between the front and back of the mouth and the internal and external surfaces of teeth, so the limited samples they collected don’t provide comprehensive insights into Richard’s overall oral microbiome.

Nevertheless, one significantly present bacterium was Tannerella forsythia, which has been associated with periodontal disease, a severe gum infection that erodes the bone that supports the teeth. Given the poor dental hygiene practices of the 15th century, Richard had cavities at the time of his death at age 32, although this does not automatically imply he suffered from periodontal disease.

“A single individual can host potentially harmful bacteria without developing any disease, while others might experience an infection,” asserts Pierre Stallforth from the Leibniz Institute for Natural Product Research and Infection Biology. Weyrich notes that further analysis focusing on bone deterioration within his jaw would be essential to ascertain if Richard indeed had periodontal disease.

“What fascinates me about this field is its ability to bridge social sciences, history, and genetics,” concludes Stallforth. “Access to dental calculus from historical personalities provides remarkable insights into their lives.”