RNA-Seq from human GUT microbiome: from small intestine
Total RNA was isolated using the PowerSoil RNA Isolation Kit (Qiagen, Hilden, Germany) following the manufacturer's instructions. 17L of total RNA was used treated with Baseline-ZERO DNase (Epicentre/Illumina, Madison, WI, USA)  to remove the DNA DNA contamination using Baseline-ZERO DNase (Epicentre/Illumina, Madison, WI, USA) followingcontamination following the manufacturer's instructions, followed by purification and concentration with the RNA Clean & Concentrator-5 columns (Zymo Research, Irvine, CA, USA). DNA free RNA samples were used for cDNA synthesis; cDNA preparation was completed using the iScript cDNA Synthesis Kit (BioRad, Hercules, CA, USA) and random primers following the manufacturers instructions. The 16S rRNA gene V4 variable region was amplified using the PCR primers 515F/806R  (bac515F GTGCCAGCMGCCGCGGTAA and bac806R GGACTACVSGGGTATCTAAT)