animal host 15,287 host-associated 15,287 digestive tract 15,145 intestine 15,030 mammalian host 14,958 human host 14,171 industrialized 10,852 adult 4,781 infant 3,633 child 1,516 urban 1,352 elderly 933 rural 772 non-industrialized 728 full term birth 631 preterm birth 311 adolescent 265 mouth 133 saliva 128 urogenital tract 125 anthropogenic 120 rumen 103 traditional agriculturalist 91 wastewater 75 aquatic 75 sewage 61 built environment 51 terrestrial 49 insect host 38 hospital 29 hunter-gatherer 21 skin 20 low temperature 16 medium temperature 9 fermented food 9 food 9 ancient microbiome 9 agriculture 5 wetland 2 lentic 2 paludal 2 soil 2 very low temperature 2 air 1 negative control 1 anaerobic 1 sludge 1