Metagenome sequencing of the Hadza hunter-gatherer gut microbiota
DNA libraries were prepared by using Illumina TruSeq DNA PCR-Free Sample Prep Kits (low-throughput protocol), following the manufacturer's instructions with some modifications. One microgram of each genomic DNA was sheared using a Covaris S2 sonication device (Covaris) in order to obtain 350 bp inserts. After sonication, DNA fragments were end-repaired and the appropriate library size was selected using different ratios of the Sample Purification Beads, then the samples were A-tailed and ligated to adapters. Because of the low quantities of the libraries obtained, an “Enrich DNA Fragments” step was introduced, according to the manufacturer's instructions of the Illumina TruSeq DNA Sample Preparation kit. Finally, size and concentration of DNA fragments were assessed using KAPA Library Quantification Kits (Kapa Biosystems) specific for the Illumina libraries. 