design: For 16S rRNA high-throughput sequencing, the primers used were 338F/806R, with the sequences being: 338F: 5-ACTCCTACGGGAGGCAGCAG-3, 806R: 5-GGACTACNNGGGTATCTAAT-3; Sequencing was carried out on the Illumina MiSeq platform, targeting the V3-V4 region.