S12h-a (CRX1827650; CRA027467)
Total microbial DNA was extracted from 0.5 g of sample using the HiPure Stool DNA Kit (Magen Biotech Co., Ltd., Guangzhou, China). DNA concentration and purity were assessed with a NanoDrop 2000 spectrophotometer (Thermo Fisher Scientific Inc., Waltham, Massachusetts, USA), and integrity was checked by electrophoresis on a 1 % agarose gel in a DYY-6C system (Beijing Liuyi Biotechnology Co., Ltd., Beijing, China) with imaging on a Tanon-2500 gel documentation system (Tanon Science & Technology Co., Ltd., Shanghai, China).