TABLE 4.

Results of pairwise PERMANOVA tests (all samples combined)

Comparison	df	pseudo-F	R2	P valuea
Between populations
Unweighted UniFrac
Peri-urban MEX versus urban USA	1	3.173	0.040	<0.01
Rural MEX versus peri-urban MEX	1	3.926	0.104	<0.01
Peri-urban MEX versus urban MEX	1	1.672	0.053	<0.05
Rural MEX versus urban USA	1	7.761	0.084	<0.01
Urban MEX versus urban USA	1	3.408	0.040	<0.01
Rural MEX versus urban MEX	1	2.173	0.054	<0.05
Weighted UniFrac
Peri-urban MEX versus urban USA	1	2.480	0.031	0.142
Rural MEX versus peri-urban MEX	1	2.388	0.066	0.142
Peri-urban MEX versus urban MEX	1	0.942	0.030	0.519
Rural MEX versus urban USA	1	4.532	0.051	<0.01
Urban MEX versus urban USA	1	2.769	0.033	0.113
Rural MEX versus urban MEX	1	1.242	0.066	0.512
Between body sitesb
Unweighted UniFrac
HA-AP	1	3.526	0.041	<0.001
HA-FH	1	2.095	0.027	<0.01
AP-FH	1	4.774	0.060	<0.001
Weighted UniFrac
HA-AP	1	23.598	0.223	<0.001
HA-FH	1	1.439	0.019	0.160
AP-FH	1	28.762	0.277	<0.001
Between infant age groupsc
Unweighted UniFrac
Older-younger	1	3.037	0.025	<0.001
Weighted UniFrac
Older-younger	1	3.966	0.033	<0.01

^aP values in boldface indicate significance.

^bHA = hands, AP = armpit, FH = forehead.

^cOlder group = 7 to 33 months, younger group = 0 to 6 months.