Periodontal health in pre-Roman Italy: a combined macroscopic and proteomics evaluation.

Periodontitis, a chronic inflammatory condition causing damage to the supporting dental tissues, informs us about past oral health in palaeopathology. Dysbiotic host-oral microbiome interactions, including poor hygiene, diseases, and genetics, are known factors. However, the role of diet has been largely overlooked until recent clinical studies highlight carbohydrate-rich diets as pro-inflammatory. In this study, we conducted an evaluation of periodontal diseases by assessing the quality of interdental septa in a sample of 63 individuals from pre-Roman Italy who lived between the 7th-4th centuries BCE, a period characterized by agricultural intensification and cereal production. Our macroscopic approach was complemented by proteomic analysis of dental calculus from a subsample of 33 individuals. Results revealed 23.0% of septa (N=1890) were affected by periodontitis with males significantly more affected than females. Moreover, periodontitis increased with age in both sexes. Proteomic analysis identified the presence of periodontal pathogens of Porphyromonas gingivalis and Treponema denticola (i.e. the ‘red complex’) in 39.4% of the individuals (13/33). While plaque accumulation triggers periodontitis, our interpretation emphasizes the role of nutrition in disease susceptibility. Carbohydrate-rich foods, such as grains, adhere to the oral cavity and nourish bacteria, exacerbating periodontal diseases. Consequently, reliance on staple crops and poor dietary diversity may have been a primary factor contributing to the proliferation of oral microbiome-related bacteria. This aligns with previous results of bone collagen stable isotope analysis which indicated a C3 plant-based diet with limited animal protein intake. Methodological limitations hinder comparisons with modern surveys or osteoarchaeological studies due to periodontitis recording inconsistencies