All mysteries
Mystery #3Tier 2microbes / digestion

What lives in your tummy?

Deep inside your gut lives a vast, hidden population of microbes: trillions of them, of hundreds of different kinds. They're not making you ill. So what are they all doing in there?

A microscope image of E. coli, a common bacterium that lives in the gut.
Photo: Eric Erbe & Christopher Pooley, USDA ARS · Public domain · via Wikimedia Commons

Your guess

What's your hunch about what all those microbes in your gut are doing for you?

There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.

Make a guess to unlock the hints and the answer.