library_construction_protocol: Total genome DNA was extracted using the QIAmp fast DNA Stool Mini Kit (Qiagen, Germany) according to the manufacturer's recommended protocol and DNA was quantified using NanoDrop 2000 (Thermo Fisher Scientific, USA). DNA libraries were produced by PCR amplicons targeting the V3 and V4 regions of the 16S rRNA gene by using 341F and 805R primers, and sequenced by using the Illumina MiSeq (Illumina, USA).