Fig. 3

Principal coordinate analysis (PCoA) plots comparing bacterial profiles based on gestation, mode of delivery and gender. PCoA plots based on a weighted UniFrac distances or b generalized UniFrac distances at alpha 0.5. Each sample, represented by a coloured circle, is plotted on this two-dimensional, two-axis plane with the first two components plotted. Samples (points) that cluster together are more similar in biota composition and abundance. As shown by the plot, the lack of distinct clustering between groups, for gestation (1st row), mode of delivery (2nd row) and gender (3rd row), indicate that no bacterial differences exist between preterm and term samples, caesarean and vaginal delivery samples, and male and female samples. PERMANOVA (p < 0.5). P_ex = extremely premature (gestation <28 weeks); P_very = very premature (gestation 29–32 weeks); P_late = late premature (gestation 33–36 weeks); T = term (gestation >37 weeks); “c_E” = elective caesarean delivery; “c_NE” = non-elective C section; “v” = vaginal delivery; “m” = male child; “f” = female child; “m_tw” = twins both male; “f_tw” = twins both female; “Twin” = male and female twins