Fig. 4. Comparison in relative abundance of dominant genera between male and female subjects. Green and red bars represent male and female subjects, respectively. Data are shown as mean±standard deviation (SD) (n=18 for males and n=17 for females), and the statistical difference is marked by red asterisks (^* P<0.05) based on non-parametric Mann-Whitney U test. Only Neisseria showed statistical differences between male and female subjects, and had a higher relative abundance in male subjects.