Human gut microbiota from PKU subject, Sample GMP3T2
Fecal DNA extraction was performed by the PSP Spin stool DNA kit (Stratec Molecular, Berlin, Germany), according to the manufacturers instructions, and stored until use at -20C. The V3V4 hypervariable regions of the bacterial 16S rRNA gene were amplified with a two-step barcoding approach according to the Illumina 16S Metagenomic Sequencing Library Preparation (Illumina, San Diego, CA, USA). Briefly, DNA samples were amplified with dual-index primers using a Nextera XT DNA Library Preparation Kit (Illumina), while library concentration and quantification were determined using a KAPA Library Quantification Kit (Kapa Biosystems, Woburn, MA, USA) and Agilent 2100 Bioanalyzer System (Agilent, Santa Clara, CA, USA), respectively. The libraries were pooled and sequenced with a MiSeq platform (Illumina) for 2  250 base paired-end reads and a total of 2.5 Gbases raw reads were obtained.