library_construction_protocol: Raw sequencing data were quality-controlled to remove low-quality and short reads using TrimGalore v0.5.0. Paired-end reads are merged using FLASH2 software, and low-quality merged sequences (with more than 90% of bases having a quality score below 20) are discarded. Usearch v8.1 filters out sequences with a total base error rate greater than 2% and sequences shorter than 100 bp. Primers are identified and removed from the sequences using mothur v1.41.1. Taxonomy was assigned as operational taxonomic units (OTUs) within the QIIME2 environment for further analysis.