a4 (CRX1935504; CRA029363)
DNA from fecal samples was extracted using a FastPureStool DNA Isolation Kit (MJYH, shanghai, China), amplified by the 338F and 806R prime pairs for the V3-V4 region of the 16S rRNA. Then the DNA amplificaiton productions was purified by the NEXTFLEX Rapid DNA-Seq Kit (Biotek, USA) for sequencing.