Question: do you use animal poop

Ciarán O'Brien answered on 19 Nov 2014:

Yup!

About half of the work I do on poop involves studying mice, so I look at mouse poop. That’s because a lot of discoveries made by other scientists have gotten to the stage where they’re almost ready to be tested on humans. But health and safety people won’t allow you to test on humans before you can show that it’s safe on animals first, so some animal testing is required. Mice are a good choice, they’re cheap to breed and keep fed, they’re small so you can run large tests with them (testing on cows would need a field full of cows, that’s expensive!)

The other half is human poop, because we need to know more about how gut bacteria affect humans (they’re much easier to ask how they’re feeling than mice!)