Proteomic Evidence of Dietary Sources in Ancient Dental Calculus

Archaeological dental calculus has emerged as a rich source of ancient biomolecules, including proteins. Previous analyses of proteins extracted from ancient dental calculus revealed the presence of the dietary milk protein β-lactoglobulin, providing direct evidence of dairy consumption in the archaeological record. However, the potential for calculus to preserve other food-related proteins has not yet been systematically explored. Here we analyse shotgun metaproteomic data from 100 archaeological dental calculus samples ranging from the Iron Age to the post-medieval period (8thC BC - 19thC AD) in Britain, as well as dental calculus from contemporary dental patients and recently deceased individuals, to characterise the range and extent of dietary proteins preserved in dental calculus. In addition to milk proteins, we detected proteomic evidence of foodstuffs such as cereals and plant products, as well as the digestive enzyme salivary amylase. We discuss the importance of optimized protein extraction methods, data analysis approaches, and authentication strategies in the identification of dietary proteins from archaeological dental calculus. Our ability to detect dietary proteins, although limited, demonstrates the potential of these methods to robustly identify foodstuffs in the archaeological record that are under-represented due to their poor preservation.