human gut metagenome
The library of fecal DNA was constructed using Nextera DNA Flex Library Preparation kit (Illumina, USA). All samples were sequenced on the Illumina HiSeq 4000 platform by Frasergen Bioinformatics Co., Ltd. The raw data was first pre-processed to eliminate the contamination of low-quality and host-associated reads. We performed data quality checks using FastQC, and then used the KneadData pipeline to perform quality control and to remove host DNA.  The second step is to profile taxonomy and metabolic potential using the read-based approach Metaphlan91. The differently enriched species were analyzed using LEfSe. The reads were further assembled to contigs through MegaHIT. The contigs were constructed by CD-HIT to remove redundant gene sets and the genes were then predicted from clean contigs by Prodiga l.