The initial number of sequence reads and the ones matching the chloroplast genome collection.

BLAST against the complete NCBI reference sequence database confirms that the chloroplast matching reads identified by the NGS alignment software Bowtie match only plant genomes and just in very few cases mammal genomes. The bacterial alignments are partly the result of the chloroplasts' genetic homology to them or may indicate the presence of circulating bacterial DNA. Among the IBD fractions, the one with largest DNA fragment size has the largest concentration.