16S rRNA gene ampl seq
Libraries were prepared by following Illumina 16S Metagenomic Sequencing Library Preparation protocol (https://support.illumina.com/documents/documentation/chemistry_documentation/16s/16s-metagenomic-libraryprep-guide-15044223-b.pdf) in two amplification steps: an initial PCR amplification using locus-specific PCR primers and a subsequent amplification that integrates relevant flow-cell binding domains and unique indices (NexteraXT Index Kit, FC1311001/FC1311002). 16S libraries were sequenced on Aviti platform (Element Biosciences, San Diego, CA) using 300-bp pairedend mode.