The Subgingival Microbiome in Patients with Down Syndrome and Periodontitis.

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, , , and were more abundant in the PDS group than in the HDS group, as were the less commonly studied , and genera. Among the species, spp. and spp. were the most abundant in the PDS group; the most abundant species in the HDS group were spp., spp. and spp.

CONCLUSION

Well-recognized periodontal pathogens and newly proposed pathogenic taxa were associated with periodontitis in patients with DS.