RT Journal Article T1 The Subgingival Microbiome in Patients with Down Syndrome and Periodontitis A1 Nóvoa, Lourdes A1 Sánchez Beltrán, María Del Carmen A1 Blanco, Juan A1 Limeres, Jacobo A1 Cuenca, Maigualida A1 Marín Cuenda, María José A1 Sanz Alonso, Mariano A1 Herrera González, David A1 Diz Dios, Pedro AB Objective: To describe the subgingival microbiome of individuals with Down syndrome (DS). Methods: We conducted a cross-sectional observational study that obtained bacterial DNA samples from 50 patients with DS, 25 with periodontitis (PDS) and 25 with a healthy periodontal condition (HDS). The samples were analyzed by sequencing the 16S rRNA gene V3–V4 hypervariable region using the MiSeq System. Taxonomic affiliations were assigned using the naïve Bayesian classifier integrated in QIIME2 plugins. We evaluated the difference in bacteria abundance between the sample groups using Wilcoxon and Kruskal–Wallis tests. We evaluated the alpha diversity of the identified species using the Observed, Chao1metric, ACE and Shannon indices and evaluated beta diversity with principal coordinate analysis (registration code: 2018/510). Results: Twenty-one genera and 39 bacterial species showed a significantly different abundance between the study groups. Among the genera, Porphyromonas, Treponema, Tannerella and Aggregatibacter were more abundant in the PDS group than in the HDS group, as were the less commonly studied Filifactor, Fretibacterium and Desulfobulbus genera. Among the species, Porphyromonas spp. and Tannerella spp. were the most abundant in the PDS group; the most abundant species in the HDS group were Pseudomonas spp., Granulicatella spp. and Gemella spp.Conclusion: Well-recognized periodontal pathogens and newly proposed pathogenic taxa were associated with periodontitis in patients with DS. PB MDPI SN 2077-0383 YR 2020 FD 2020-08-02 LK https://hdl.handle.net/20.500.14352/8343 UL https://hdl.handle.net/20.500.14352/8343 LA eng NO Nóvoa, L., Garrido Sánchez, M. C., Blanco, J. et al. «The Subgingival Microbiome in Patients with Down Syndrome and Periodontitis». Journal of Clinical Medicine, vol. 9, n.o 8, agosto de 2020, p. 2482. DOI.org (Crossref), https://doi.org/10.3390/jcm9082482. NO Xunta de Galicia NO Agencia Gallega de Innovación (España) DS Docta Complutense RD 10 abr 2025