Fecal transplants are exactly what you probably think they are; one person’s poop is inserted into another person’s ass. A procedure normally used to treat a severe condition, scientists have found that fecal transplants also help mice regulate weight in addition to other potential benefits.

Thanks to science, we now know poop from a skinny mouse actually makes a fatter mouse skinnier, and it works vice versa too! You probably don’t want to know more.