Research Corner - Ancient dental calculus

Dr Kitty Guo, our ECG Academic representative, has kindly written a precis of a really thought-provoking article that was recently published. Click on the link below to access the full article, to read more about fossilised periodontal microbes and the implications that they have on the understanding of disease and antimicrobial resistance:

Inferring diet, disease and antibiotic resistance from ancient human oral microbiomes 

• Gwyn Dahlquist-Axe1​, Francesca J. Standeven1​, Camilla F. Speller2​, Andrew Tedder1​ and Conor J. Meehan3​
•  View Affiliations
• Published: 13 May 2024 

Ancient dental calculus

Dahlquist-Axe et al. explore fascinating insights into the evolution of the oral microbiome through analysis of ancient dental calculus. Calculus is unique in its ability to preserve microbial DNA which can then be isolated and sequenced. The use of ancient DNA extracted from calculus has allowed for an understanding of changes in human society over tens of thousands of years.

One of the most notable findings to periodontology is the identification of the same Socransky red complex bacteria in both modern and ancient individuals across the world, including ancient Egyptian mummies.

When considering systemic disease, the analysis of ancient calculus has enabled the detection of systemic pathogens, including a leprosy causing bacteria, where there were no other detectable signs on the ancient remains.

Of particular significance to the global human population is the potential for ancient microbiomes to improve our understanding of the mechanisms of how antibiotic resistance evolves. Because antimicrobial resistance is a natural process, accelerated by the use of antimicrobial drugs, it is valuable to understand the naturally occurring resistance genes that existed in individuals prior to the use of antibiotic drugs and the evaluation of dental calculus from ancient human remains can give us this insight that modern human microbiomes cannot.

The paper identifies limitations in evaluating ancient calculus, particularly the bias of microbial species that are preserved in calculus, compared with those that are not preserved in dental plaque or the many other niches of the oral cavity, as well as the potential for contamination. It highlights a need for continued research in this area, but overall identifies that ancient dental calculus is a unique and valuable window into the past.

View research paper: https://www.microbiologyresearch.org/content/journal/mgen/10.1099/mgen.0.001251