Why do I have to share my body with so many bugs?

You might only be 10% human

You are not all human. You aren’t even mostly human.

The combined number of cells from microscopic organisms in the human body – such as bacteria, archaea, fungi and viruses – vastly outnumber human cells. Some estimates suggest it may be as much as 10 to one, others are more conservative. But whatever the precise figure, the fact is, we're out-gunned. These organisms make up what’s called your ‘microbiome' and your body contains about three pints of it. The vast majority of these microbes are bacteria – and we carry around 100 trillion of them. That’s 100,000,000,000,000.

But don’t worry – they aren't all bad. Quite the contrary. You need most of these bugs to lead a healthy and happy life.

CLICKABLE: Meet your bugs

Different species of bacteria like to make their home in various habitats in and on your body.

Meet some of your resident bugs by clicking on the body part labels in the image below.

CLICKABLE: How can I hack my bugs?

How can the richness of the bacteria you harbour be improved?

Click on the labels to find out.

Learn more about this topic:

Did climate change make us intelligent?
Amazing Me
What does my wee say about me?