Table 3.

Average relative abundance of the top 15 bacterial genera in high schools in Shanxi and their relative abundance in other habitats. The bacterial abundance in air, non-saline soil and freshwater, and the human gut, saliva and skin environment were calculated from the Earth Microbiome Project [41]. The bacterial abundance in the university dormitory and junior high school was calculated from two recent publications [12, 42]. Taxa with relative abundance > 0.1% were formatted with bold font

Taxa	High school (%)	Air (%)	Soil (%)	Water (%)	Human gut (%)	Human saliva (%)	Human skin (%)	University dormitory, China (%)	Junior high school, Malaysia (%)
Psychrobacter	5.36	0.12	< 0.01	0.01	0	< 0.01	0.18	0.04	0
Kocuria	3.82	< 0.01	< 0.01	< 0.01	< 0.01	0.02	0.43	0.25	1.43
Brachybacterium	3.41	0.16	0.02	< 0.01	0.03	< 0.01	0.59	0.23	0.71
Micrococcus	3.22	0.10	< 0.01	< 0.01	< 0.01	< 0.01	0.65	0.54	0.82
Acinetobacter	2.99	2.30	0.10	1.37	0.02	0.21	4.93	23.2	2.21
Microbacterium	2.93	0.03	0.10	0.06	< 0.01	< 0.01	0.03	0.75	0
Paracoccus	2.80	0.18	0.01	0.13	< 0.01	< 0.01	0.32	0.13	3.13
Nocardioides	2.55	0.06	0.03	0.01	0	< 0.01	0.04	0.03	0.46
Streptococcus	2.09	5.46	0.16	0.16	0.37	19.97	10.78	0.49	1.45
Pseudomonas	2.04	1.41	1.29	2.57	< 0.01	0.01	5.44	1.88	0.80
Corynebacterium	1.71	1.06	0.04	0.02	0.89	0.43	7.66	0.95	1.77
Janibacter	1.56	< 0.01	< 0.01	< 0.01	< 0.01	< 0.01	0.04	0.04	0.64
Planococcus	1.50	< 0.01	0.02	< 0.01	0	0	< 0.01	<0.01	0
Arthrobacter	1.39	0.21	0.39	0.04	< 0.01	0.02	0.13	0.09	0.48
Serinicoccus	1.32	0.07	< 0.01	< 0.01	< 0.01	< 0.01	0.04	<0.01	0