host-associated 2,117 animal host 2,095 mammalian host 2,028 human host 2,001 industrialized 1,748 terrestrial 1,528 anthropogenic 1,467 skin 1,416 built environment 1,387 adult 856 digestive tract 667 elderly 546 intestine 432 infant 307 mouth 273 hospital 222 preterm birth 178 saliva 157 urban 156 aquatic 130 soil 113 wastewater 72 sludge 58 child 44 airways 43 fresh water 33 medium temperature 24 subsurface 22 plant host 22 groundwater 20 rhizosphere 18 low salinity 18 sewage 17 tundra 17 contaminated 16 agriculture 15 full term birth 15 lentic 15 very low temperature 12 wetland 12 grassland 12 forest 12 paludal 12 lacustrine 11 urogenital tract 10 anaerobic 10 adolescent 9 permafrost 9 benthic 8 lake bed 8 sediment 8 rural 8 ice 6 marine 6 low temperature 5 high salinity 5 arid 3 cropland 3 non-industrialized 3 phyllosphere 3 mine 3 negative control 3 fermented food 2 stream 2 littoral 2 food 2 traditional agriculturalist 1 ancient dental calculus 1 alkaline 1 pelagic 1 ancient microbiome 1