There are many trillions of microbial organisms, including fungi, bacteria and viruses, living in and on our bodies, outnumbering our own cells 3 to 1. We have battled them for years, with antibiotics and disinfectants. But as we get to know them better, a lot turn out to be our allies, while others remain our constant enemies.
A microbiome is the community of micro-organisms living together in a particular habitat. Humans, animals and plants have their own unique microbiomes, but so do soils, oceans and even everyday objects.