design: DNA was extracted using the Qiagen DNeasy PowerSoil Pro Kit (Qiagen, Hilden, Germany). After the quality control procedures using a Qubit 2.0 fluorometer (Thermo Fisher Scientific, Waltham, MA, USA) and agarose gel electrophoresis with Agilent 2100 (Agilent Technologies, Santa Clara, CA, USA), Illumina sequencing libraries were prepared using the NEBNext Ultra II DNA Library Preparation Kit for Illumina (NEB, Ipswich, MA, USA). Metagenomic libraries were sequenced on the Illumina NovaSeq 6000 platform, targeting ~6 Gb of sequence per sample with 150 bp, paired-end reads.