Experimental tests strongly challenge the evidence of a healthy human blood microbiome

The study critically evaluate the results of 16S targeted amplicon sequencing performed on the total DNA collected from healthy donors’ blood samples in the light of specific negative controls. Total DNA was extracted from the blood of healthy subjects and from negative controls (whose DNA concentration has been inflated through known spyke DNA), amplified to collect amplicons of variable V3–V4 regions (primers 341F and 805R) of the bacterial 16s rRNA gene and sequenced with MiSeq (2x300bp) Illumina platform.