FIG 2.

Age exerts the strongest effect on bacterial relative abundance. The percentages of taxa that are significantly associated with age, sex, living environment, or reproductive state, across six taxonomic levels are shown. The significance of the difference was verified by using a Kruskal-Wallis rank sum test (or Mann-Whitney U test [for two-sample groups]). Only taxa with P values <0.05 were considered significant. The numbers below the bars indicate the total taxa measured per level, while the numbers above depict the number of taxa significantly differentially abundant.