Oral microbiome in down syndrome and its implications on oral health

J Oral Microbiol. 2020 Dec 30;13(1):1865690. doi: 10.1080/20002297.2020.1865690.

Abstract

Introduction: The oral cavity harbors an abundant and diverse microbial community (i.e. the microbiome), whose composition and roles in health and disease have been the focus of intense research. Down syndrome (DS) is associated with particular characteristics in the oral cavity, and with a lower incidence of caries and higher incidence of periodontitis and gingivitis compared to control populations. However, the overall composition of the oral microbiome in DS and how it varies with diverse factors like host age or the pH within the mouth are still poorly understood. Methods: Using a Citizen-Science approach in collaboration with DS associations in Spain, we performed 16S rRNA metabarcoding and high-throughput sequencing, combined with culture and proteomics-based identification of fungi to survey the bacterial and fungal oral microbiome in 27 DS persons (age range 7-55) and control samples matched by geographical distribution, age range, and gender. Results: We found that DS is associated with low salivary pH and less diverse oral microbiomes, which were characterized by lower levels of Alloprevotella, Atopobium, Candidatus Saccharimonas, and higher amounts of Kingella, Staphylococcus, Gemella, Cardiobacterium, Rothia, Actinobacillus, and greater prevalence of Candida. Conclusion: Altogether, our study provides a first global snapshot of the oral microbiome in DS. Future studies are required to establish whether the observed differences are related to differential pathology in the oral cavity in DS.

Keywords: Candida; Oral microbiome; down syndrome; oral mycobiome.

Grants and funding

The project was financed by the CRG through Genomics and Bioinformatics Core Facilities funds, and by the EduCaixa programme through funds from the Fundación Bancaria ‘La Caixa,’ with the participation of the Center for Research into Environmental Epidemiology (CREAL), and the ‘Center d’Excellència Severo Ochoa 2013-2017’ programme (SEV-2012-02-08) of the Ministry of Economy and Competitiveness. Eppendorf, Illumina, and ThermoFisher sponsored the research by donating some materials and reagents. TG group acknowledges support from the Spanish Ministry of Science and Innovation for grant [PGC2018-099921-B-I00], cofounded by European Regional Development Fund (ERDF); from the CERCA Programme/Generalitat de Catalunya; from the Catalan Research Agency (AGAUR) SGR423; from the European Union’s Horizon 2020 research and innovation programme under the grant agreement [ERC-2016-724173]; from Instituto de Salud Carlos III [INB Grant PT17/0009/0023 - ISCIII-SGEFI/ERDF].