The links among different parts of the human body are full of surprises, but here's one you might not have considered: Could a thing that causes dandruff on your head also be contributing to your digestive problems?

That's one mystery that scientists are trying to unravel with research into the fungi that live in your gut. While the bacteria that colonise our intestines have been a scientific focus for more than a decade, the fungal critters there are starting to get more attention.