The right type of germs might be able to help fight fat.
Researches found different kinds of bacteria that live inside the gut can help spur obesity or protect against it.
The researchers transplanted intestinal germs from fat of skinny people into mice, and watched the rodents change.
Whether or not the good germs could move in and do their job was determined by what they ate.
The report raises the possibility of one day turning gut bacteria into personalized fat fighting therapies.