title: 16s sequencing data 13
design: SDS methods was employed for the extraction of DNA from the samples, and agarose gel electrophoresis was utilized to assess the purity and concentration of the extracted DNA. Subsequently, an appropriate amount of DNA was taken into a centrifuge tube and diluted to 1 ng/L with sterile water. PCR amplification was performed using primers for the 16S V4 region (515F and 806R). The PCR products were detected by electrophoresis in 2% agarose gel, and the samples were mixed in equal quantities according to the concentration of PCR products. After fully mixing, the samples were detected again by electrophoresis in 2% agarose gel. The target bands were recovered by gel recovery kit provided by Qiagen company. According to the standard operating procedure of PCR library construction, the purified amplification fragments were constructed into Illumina library, and the PE300 sequencing was performed on the Illumina Miseq platform.