Scientists can use ancient DNA from dental calculus to analyze the oral microbiome and thus understand the eating habits of prehistoric humans,.
The oral microbiome is susceptible to change while being influenced by ecological and living environments.
A recent study published in Nature Communications suggests that the ancient oral microbiome may have changed as the diet of Neolithic populations transitioned from hunting and gathering to agriculture.
Using DNA from dental calculus, the researchers studied the oral microbiomes of 76 individuals from prehistoric Italy, covering the Late Paleolithic (31,000-11,000 B.C.), Neolithic (6,200-4,000 B.C.), and Bronze Age (3,500-2,200 B.C.).
They combined these data with microscopic food remnants also found in dental calculus, as well as archaeological findings.
In the nearly 30,000 years of data before and after, the scientists identified that dietary changes went through a shift from reliance on hunting, to the introduction of fermentation and dairy products, and finally to a reliance on carbohydrates associated with an agricultural diet.
The researchers also made connections between microbial changes and dietary evidence (food debris in dental plaque) and food processing (food residues and animal remains on millstones).
The findings provide insight into the evolution of the ancient oral microbiome associated with dietary changes in prehistoric European populations.