16S rRNA-Seq of saliva
Paired-end (2250 bp) Illumina reads were imported into the QIIME2 platform for downstream analysis. Sequence quality control and denoising were performed using the DADA2 algorithm implemented in QIIME2. Regions with a quality score concentration below 30 were filtered out, and Amplicon Sequence Variants (ASVs) were generated accordingly.The resulting ASVs were taxonomically assigned against the SILVA 138 reference database, and taxonomic tables were constructed. Files generated by QIIME2 were subsequently processed in the R programming environment using RStudio for data visualization and biostatistical analyses.