Raw paired-end reads obtained via Illumina MiSeq sequencing were demultiplexed and processed using Cutadapt (v1.18) to remove primer sequences. QIIME2 was used for quality control, with DADA2 for denoising and chimera removal, and q34-vsearch for merging paired-end reads. Amplicon sequence variants (ASVs) were generated and rarefied to the minimum sequencing depth across samples.