host-associated 672 digestive tract 672 animal host 672 intestine 672 mammalian host 546 human host 545 industrialized 473 adult 175 elderly 110 urban 44 rural 9 adolescent 7 anthropogenic 7 infant 7 fermented food 6 food 6 non-industrialized 3 child 2 anaerobic 1 sludge 1 terrestrial 1 full term birth 1 agriculture 1 cropland 1 medium temperature 1