ETR4
In this study, fecal samples were collected from adult animals, immediately flash-frozen in liquid nitrogen, and stored at 80 C until DNA extraction. Microbial genomic DNA was extracted from each fecal sample (250500 mg) using E.Z.N.A.Soil DNA Kit (Omega Bio-Tek, Norcross, GA, USA), following the manufacturers instructions. The concentration and purity of the extracted DNA were assessed using a NanoDrop 2000 UV-Vis spectrophotometer (Thermo Scientific, Wilmington, MA, USA) and 9% agarose gel electrophoresis.