 Metagenomic shotgun sequencing For metagenomic sequencing extracted genomic DNA will be physically sheared to an average fragment size of 250 bp. The fragmented gDNA will be sequenced bi-directionally 100 bp each direction on a lane of an Illumina HighSeq. Quality filtering will be performed with Trimmomatic 17, after which the paired and unpaired forward reads will be combined and reads with more than 10 ambiguous bases will be removed. Next, the reads will be screened for human sequences with Best Match Tagger v3.101 18, after which human reads and duplicate reads will be removed. 