title: S56
design: the resulting sequences were merged with FLASH (v1.2.7) and quality filtered with fastp (0.19.6). High-quality sequences were further processed by the DADA2 plugin for de-noising. Taxonomic assignment of ASVs was performed using the Naive bayes consensus taxonomy classifier implemented in QIIME 2.0 and the SILVA reference database (silva 138/16s_bacteria).