Difference in microbial community composition between males and females. Nodes represent taxa, edges link the different taxonomic levels. The fold increase is calculated as the 2log of the ratio of the relative in males and females (0 = no difference between genders, 1 = twice as abundant in female, and so on). The significance is expressed as the P-value of a Mann-Whitney U test of the male and female samples. Note that the relation between node-size and total abundance is non-linear.
Zeeuwen et al. Genome Biology 2012 13:R101 doi:10.1186/gb-2012-13-11-r101