Heritage-specific oral microbiota in Indigenous Australian dental calculus

Matilda Handsley-Davis; Kostas Kapellas; Lisa M Jamieson; Joanne Hedges; Emily Skelly; John Kaidonis; Poppy Anastassiadis; Laura S Weyrich

doi:10.1093/emph/eoac024

Heritage-specific oral microbiota in Indigenous Australian dental calculus

Evol Med Public Health. 2022 Aug 5;10(1):352-362. doi: 10.1093/emph/eoac024. eCollection 2022.

Authors

Matilda Handsley-Davis¹, Kostas Kapellas², Lisa M Jamieson², Joanne Hedges², Emily Skelly¹, John Kaidonis³, Poppy Anastassiadis³, Laura S Weyrich¹

Affiliations

¹ Australian Centre for Ancient DNA (ACAD), School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.
² Australian Research Centre for Population Oral Health (ARCPOH), Adelaide Dental School, University of Adelaide, Adelaide, SA, Australia.
³ Adelaide Dental School, University of Adelaide, Adelaide, SA, Australia.

Abstract

Background and objectives: Aboriginal Australians and Torres Strait Islanders (hereafter respectfully referred to as Indigenous Australians) experience a high burden of chronic non-communicable diseases (NCDs). Increased NCD risk is linked to oral diseases mediated by the oral microbiota, a microbial community influenced by both vertical transmission and lifestyle factors. As an initial step towards understanding the oral microbiota as a factor in Indigenous health, we present the first investigation of oral microbiota in Indigenous Australian adults.

Methodology: Dental calculus samples from Indigenous Australians with periodontal disease (PD; n = 13) and non-Indigenous individuals both with (n = 19) and without PD (n = 20) were characterized using 16S ribosomal RNA gene amplicon sequencing. Alpha and beta diversity, differentially abundant microbial taxa and taxa unique to different participant groups were analysed using QIIME2.

Results: Samples from Indigenous Australians were more phylogenetically diverse (Kruskal-Wallis H = 19.86, P = 8.3 × 10^-6), differed significantly in composition from non-Indigenous samples (PERMANOVA pseudo-F = 10.42, P = 0.001) and contained a relatively high proportion of unique taxa not previously reported in the human oral microbiota (e.g. Endomicrobia). These patterns were robust to stratification by PD status. Oral microbiota diversity and composition also differed between Indigenous individuals living in different geographic regions.

Conclusions and implications: Indigenous Australians may harbour unique oral microbiota shaped by their long relationships with Country (ancestral homelands). Our findings have implications for understanding the origins of oral and systemic NCDs and for the inclusion of Indigenous peoples in microbiota research, highlighting the microbiota as a novel field of enquiry to improve Indigenous health.

Keywords: Aboriginal Australian; Indigenous Australian; evolutionary medicine; microbiome; microbiota; oral health.