TABLE 2.

Descriptive information and statistics for each group, i.e., children group (cheek [CCHG], abdomen [ACHG]), youth group (cheek [CYHG], abdomen [AYHG]), middle-aged group (cheek [CMAG], abdomen [AMAG]), and elder group (cheek [CELG], abdomen [AELG]).

Group		Exposed sampling sites				Non-exposed sampling sites
		Row tags (Mean ± SD)	OTUs (Mean ± SD)	Chao 1 (Mean ± SD)		Row tags (Mean ± SD)	OTUs (Mean ± SD)	Chao 1 (Mean ± SD)
16S rRNA sequencing	CCHG	57,314.95 ± 18,550.61	706.95 ± 142.04	871.00 ± 136.36	ACHG	55,010.35 ± 14,018.03	693.75 ± 150.12	790.94 ± 124.74
	CYHG	57,314.95 ± 18,550.61	765.40 ± 195.63	906.98 ± 160.88	AYHG	52339.65 ± 15,372.78	627.35 ± 69.63	773.09 ± 74.51
	CMAG	68,455.80 ± 18,127.31	736.30 ± 130.98	1002.43 ± 133.11	AMAG	64,877.40 ± 16,541.71	721.55 ± 149.22	977.68 ± 173.76
	CELG	76,821.60 ± 34,202.71	792.80 ± 135.89	1,113.29 ± 154.79	AELG	67,124.55 ± 16,017.87	859.20 ± 214.47	1,132.56 ± 213.50
ITS gene sequencing	CCHG	57,314.98 ± 78,550.61	629.35 ± 144.07	831.37 ± 169.83	ACHG	81,292.35 ± 36,065.16	432.45 ± 157.85	613.31 ± 155.83
	CYHG	59,893.50 ± 15,931.53	665.20 ± 189.05	878.92 ± 250.46	AYHG	77,415.25 ± 44,384.18	474.20 ± 221.25	658.61 ± 315.54
	CMAG	68,455.80 ± 18,127.31	757.55 ± 96.95	1,047.49 ± 139.19	AMAG	95,945.80 ± 51,417.13	772.60 ± 174.85	1,024.11 ± 205.99
	CELG	76,821.60 ± 34,202.71	631.35 ± 271.73	867.09 ± 383.69	AELG	127,038.30 ± 58,757.97	594.80 ± 275.75	843.19 ± 387.64

Variables are represented as mean ± standard deviation according to row tags, OTUs, and species richness indices (Chao 1 indices).