Table 1.

Community structure similarity is higher for samples in the same digestive tract group than for samples in different groups or outside the digestive tract

	Digestive tract groups				Non-digestive
	G1	G2	G3	G4	tract samples
G1	0.58 ± 0.14	0.43 ± 0.17	0.32 ± 0.13	0.02 ± 0.03	0.04 ± 0.06
G2	0.43 ± 0.17	0.51 ± 0.14	0.39 ± 0.11	0.05 ± 0.05	0.04 ± 0.06
G3	0.32 ± 0.13	0.39 ± 0.11	0.49 ± 0.14	0.03 ± 0.04	0.07 ± 0.08
G4	0.02 ± 0.03	0.05 ± 0.05	0.03 ± 0.04	0.53 ± 0.17	0.03 ± 0.07
Non-digestive tract	0.04 ± 0.06	0.04 ± 0.06	0.07 ± 0.08	0.03 ± 0.07	0.29 ± 0.31

Average Bray-Curtis index and standard deviations are reported for samples in each of the four digestive tract groups and body sites outside of the digestive tract. In bold are highlighted the within group similarity values that are statistically significantly higher (t-test P < 1e-20) than any between-group distances. The body sites outside of the digestive tract included three vaginal sites (posterior fornix, mid-vagina, vaginal introitus), the nasal cavity (anterior nares), and two skin sites (antecubital fossae and retroauricular crease).