microbiome

Instead of eating a typical breakfast every day, Jonah Reeder gulps down a special protein shake.

"The nutrients in it like to sit at the bottom, so I usually have to shake it up and get all the nutrients from the protein and everything," says Reeder, 21, of Farmington, Utah, as he shakes a big plastic bottle.

Antibiotics can save lives, but sometimes they can work too well.

Most antibiotics can't tell the difference between good and bad bacteria. That means the medicines kill helpful bacteria in your gut while they're obliterating the bacteria making you sick.