Effect of collection-processing method from sequencing at WEHI (A,B,C) or BCM (D,E,F). (A,D) Log of standardised counts (scaled by library size) of the four most abundant phyla. Points show mean and bars standard deviation (sd) for each individual and collection-processing method. Method A has the smallest average sd for Bacteroidetes and Actinobacteria. (B,E) The Inverse-Simpson α diversity index for each sample (compare with Fig. 2). (C,F) Mean log (standardised count) plotted against the mean over the collection-processing methods, and a linear regression applied. Method A has the greatest average deviation from the linear model for the WEHI data set.