16S rRNA library from Rattus norvegicus feces (YHGTD group, Rep 4)
Total microbial genomic DNA was extracted from fecal samples using the E.Z.N.A Soil DNA Kit. The hypervariable V3-V4 region of the bacterial 16S rRNA gene was amplified with primers 338F (5'-ACTCCTACGGGAGGCAGCAG-3') and 806R (5'-GGACTACHVGGGTWTCTAAT-3'). DNA quality was verified by 1.0% agarose gel electrophoresis and NanoDrop-2000 spectrophotometry. Sequencing was performed on Illumina NextSeq 2000 with dual-indexed libraries (i7/i5 barcodes), demultiplexed using bcl2fastq. Raw sequences were processed with fastp (v0.20.0) for quality filtering, FLASH (v1.2.11) for read merging, and Uparse (v7.1) for OTU clustering (97% similarity). Taxonomy was assigned via RDP Classifier (v2.2) against the Silva 138 database (70% confidence threshold). Analysis was conducted on the Majorbio Cloud Platform.