MG_2
samples were collected from each group to extract DNA. 16S rDNA V3 + V4 region was amplified with specific primers (F: 5-3 ACTCCTACGGGAGGCAGCAG, R: 5-3 GGACTACHVG GGTWTCTAAT), and the PCR product was purified. The purified amplification product sequencing library was constructed.