Principal coordinate plots (PCoA). Clustering of microbial taxa from each individual at each collection time point. The lilac circle represents post-SI bacterial sequences, whilst the pale blue and yellow circles represent non-SI bacterial sequences—both circles relate solely to the co-habiting couple. Panel A represents pubic hair microbial taxa from male (orange) and female (red) participants. Panel B represents scalp hair microbial taxa from male (green) and female (blue) participants. Panel C represents microbial taxa present in male and female scalp and pubic hair samples.