Ordination of bacterial OTUs.

Principal coordinate analysis (PCoA) of all 835 OTUs using the weighted UniFrac metric for the size-normalized data set (7018 sequence reads per sample). Blue, magenta and green circles correspond to samples from control, low and high violacein dose groups, respectively. The five most dominant bacterial taxa (at family level) are presented. The size of their symbols represents the respective, mean relative abundance across the data set. The correlation between the bacterial taxa abundances and the treatment determined the position of them in the ordination space.