16S rRNA sequencing of Homo sapiens: human fecal microbiota
All the samples, were transported at room temperature to the La-boratories of the University of Rome Tor Vergata, Italy, to proceed with DNA extraction. The protocol of QIAamp Fast DNA Stool Mini Kit (Qiagen Ltd., Hilden, Germany) was used following the manufacturer's instructions and the DNA quantification was per-formed using Thermo Scientific NanoDrop 2000 Spectrophotometer. The 3-10 ng/L of DNA from human stool samples was sent to the Laboratory of BMR Genomics S.r.l. (Padova, Italy) to bacterial 16s rDNA gene sequencing. The V3-V4 hyper-variable regions of the 16S rDNA gene were amplified by a first PCR step using universal 16S primers [25] to generate a sequencing library in Fastq format.