Researchers deduce that the appendix is designed to protect good bacteria in the gut. That way, when the gut is affected by a bout of diarrhea or other illness that cleans out the intestines, the good bacteria in the appendix can repopulate the digestive system and keep you healthy.

What was the appendix originally used for?

Some studies suggest that as ancient humans were predominantly herbivorous, they used their appendixes for digestion. However, as humans evolved, they started to include more easily digestible food in their diet and the appendix eventually lost it function.

Was the appendix ever useful?

The appendix, notorious for its tendency to become inflamed or even rupture, has historically been viewed as a vestigial organ with no real function. But new research supports the idea that the appendix may indeed serve a purpose: to protect beneficial bacteria living in the gut.