title: 16s rDNA sequencing of human feces: patients with rheumatoid arthritis
design: We used E.Z.N.A. Stool DNA Kit (D4015, Omega, Inc., USA) to extract DNA, and amplified 16S rRNA gene with primers 341F (5'-CCTACGGGNGGCWGCAG-3') and 805R (5'-GACTACHVGGGTATCTAATCC-3'), targeting the V3-V4 region. The Illumina NovaSeq platform was used for DNA sequencing according to the manufacturer's recommendations.