beneficial bacteria

Jonah Reeder prepares a special protein shake that helps him manage a metabolic condition called phenylketonuria. Julia Ritchey/KUER hide caption

It's a bacteria-eat-bacteria world, scientists say. Bdellovibrio bacteriovorus, shown here in false color, attacks common germs six times its size, then devours them from the inside out. Alfred Pasieka/Science Source hide caption