title: methodolog
design: Metagenomic sequencing was performed on samples at different stages. Firstly, the original sequence is treated with quality control. Secondly, the sequence after quality control is spliced and combined. Genes with nucleic acid length 100 bp were selected and translated into amino acid sequences. CD-HIT software was used to cluster the predicted gene sequences and construct gene sets. Subsequently, BLASTP, NR and eggNOG databases were compared to annotate and classify different genes.