Table 3. Diversity estimators of the 16S rRNA sequencing communities at the GLOTU, FLOTU and OLOTU levels.

	OTUs	Chao	Shannon	Good’s coverage
Groups∖ Genus level
elderly.hea.cheeks	167	263.67	3.0847	98.39
elderly.hea.foreheads	147	227.47	2.7066	98.52
middle.hea.foreheads1	109	193.56	2.5080	98.87
middle.hea.foreheads2	111	186.99	2.5515	98.83
teenage.acn.cheeks1	163	260.24	3.0019	98.28
teenage.acn.cheeks2	142	224.69	2.6665	98.52
teenage.acn.foreheads	136	236.68	2.5917	98.46
teenage.hea.cheeks	131	212.90	2.7649	98.68
teenage.hea.foreheads1	143	229.48	3.0622	98.58
teenage.hea.foreheads2	134	200.10	3.0875	98.65
Groups∖ Family level
elderly.hea.cheeks	99	131.67	2.8307	99.29
elderly.hea.foreheads	93	135.94	2.5212	99.17
middle.hea.foreheads1	69	102.95	2.2783	99.41
middle.hea.foreheads2	76	111.55	2.4337	99.33
teenage.acn.cheeks1	101	136.84	2.7659	99.21
teenage.acn.cheeks2	95	130.59	2.4995	99.24
teenage.acn.foreheads	89	130.71	2.4378	99.19
teenage.hea.cheeks	81	114.74	2.5648	99.34
teenage.hea.foreheads1	90	128.98	2.8708	99.23
teenage.hea.foreheads2	87	110.30	2.7606	99.28
Groups∖ Order level
elderly.hea.cheeks	47	59.39	2.2825	99.72
elderly.hea.foreheads	45	61.94	2.1036	99.66
middle.hea.foreheads1	34	48.39	1.9063	99.74
middle.hea.foreheads2	38	52.35	1.9449	99.72
teenage.acn.cheeks1	48	63.53	2.1330	99.67
teenage.acn.cheeks2	46	59.56	2.0276	99.72
teenage.acn.foreheads	44	59.26	2.0340	99.69
teenage.hea.cheeks	41	53.71	1.9518	99.72
teenage.hea.foreheads1	48	63.00	2.2126	99.67
teenage.hea.foreheads2	41	50.98	1.9927	99.72