host-associated 26,570 animal host 26,238 mammalian host 25,361 digestive tract 24,081 human host 23,389 intestine 22,242 industrialized 18,604 adult 8,920 terrestrial 4,782 aquatic 4,695 infant 4,305 anthropogenic 3,270 mouth 2,684 elderly 2,526 child 2,428 urban 2,408 built environment 2,379 marine 1,870 skin 1,818 saliva 1,770 soil 1,732 fresh water 1,521 lentic 1,445 low salinity 1,356 rural 1,333 non-industrialized 1,248 pelagic 844 lacustrine 826 full term birth 690 high salinity 650 preterm birth 559 wastewater 551 adolescent 529 paludal 463 wetland 463 sludge 439 medium salinity 397 brackish water 390 plant host 335 forest 328 lotic 304 agriculture 297 stream 295 airways 271 fluvial 259 very low temperature 258 hospital 257 benthic 236 rumen 231 permafrost 230 low temperature 226 rhizosphere 219 saline water 215 subsurface 215 estuary 201 groundwater 196 urogenital tract 186 sediment 165 contaminated 165 traditional agriculturalist 161 cropland 140 tundra 139 grassland 134 medium temperature 129 microaerobic 128 sewage 115 insect host 111 ice 87 littoral 87 mine 81 arid 81 hunter-gatherer 74 anaerobic 70 air 70 acidic 65 alkaline 61 plant litter 53 spring 42 sea floor 35 phyllosphere 35 food 34 hot spring 31 coral reef 29 very high salinity 28 ancient microbiome 22 fermented food 21 lake bed 20 dairy product 13 very high temperature 13 hydrothermal vent 11 briny water 8 negative control 8 ancient dental calculus 6 stream bed 6 waste 6 high temperature 6 salt marsh 5