The fecal samples were collected from the human feces
Microbial community genomic DNA was extracted from fecal samples using an E.Z.N.A.R Soil DNA Kit (Omega Biotek, Norcross, GA, United States) according to the manufacturers instructions. The V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplied with the primer pair 338F and 806R by an ABI GeneAmpR 9700 PCR thermocycler (ABI, CA, United States).