What if we told you that only a mere 10 percent of your body is actually human?
Well it's true – you're actually not alone in that body of yours at all. It is in fact an ecosystem of microbes.
There's trillions and trillions of cells in our bodies, but only 10 percent of them are human. The others are about 6kg worth of bacterial cells and cells, but without them, we'd die.
Massey University senior lecturer in molecular bioscience Heather Hendrickson joined Paul Henry in studio this morning to explain more.
Watch the video for the full interview.