DNA was isolated using QIAamp PowerFecal Pro DNA-kit (QIAGEN , Hilden, Germany). Finally, DNA preparation was subjected to quality control by spectrophotometry on a NanoDrop 2000c spectrophotometer (Thermo Fisher Scientific, Waltham, United States). Fecal DNA was quantified using a Qubit Fluorometer (Themo Fisher Scientific, Carlsbad, United States). Sequencing libraries were prepared with Nextera XT Library kit (Illumina, San Diego, United States) following the manufacturers instructions. The samples were sequenced using a NovaSeq 6000 platform with paired-end reads of 151 base pairs.