Extended Data Fig. 6. Estimation of bacterial-to-human DNA ratio by qPCR.
(a) Absolute quantification of bacterial DNA by 16S qPCR in meconium and negative control samples. (b) Negative correlation of 16S copy number and human DNA percentage in metagenomic sequencing (two-sided test of Spearman correlation, ρ = −0.6, P = 2×10−9, n = 88). (c) Positive correlation between beta-actin copy number and human DNA percentage (two-sided test of Spearman correlation, ρ = 0.4, P = 3×10−4, n = 88). (d) Negative correlation between estimated bacterial-to-human DNA ratio and human DNA percentage (two-sided test of Spearman correlation, ρ = −0.8, P = 2×10−16, n = 48, samples were excluded if either measurement was below the limit of detection). The linear regression estimate is indicated with a solid black line and the 95% confidence interval is indicated by the grey area.