design: The contents of 3 periodontal pockets of each of 30 patients were collected using a sterile curette. DNA isolation was performed using the Sorb-GMO-A kit (Synthol). DNA from the samples was either isolated upon receipt or frozen at -20C for subsequent isolation within 1-3 days. Library preparation was carried out using the Fast FS DNA Library Prep Set (MGI). Sequencing was performed on a DNBSEQ-G400 instrument (MGI) using the DNBSEQ-G400RS High-throughput Sequencing Kit (FCL PE200). Sequencing was performed in paired-end mode 2 X 200 bp and dual barcode reading 2 X 10 bp. Reads' QC, decontamination and removing of human reads were carried out with Kneaddata v0.12.0.