design: For sequencing, the V3 - V4 regions of the 16S rDNA were amplified. Library preparation was performed according to the Illumina protocol, using the NextSeq2000 platform and a 600-cycle p1 reagent kit (Cat No. 20075294), with a 30% PhiX spike-in to ensure sequencing quality. The sequencing generated paired-end reads with sufficient coverage to analyze microbial diversity and composition.