The appendix is an organ thought to have gone the way of our wisdom teeth and body hair: At one point we all needed them, now people can get by just fine without them. However, it turns out, at least the appendix has some purpose in the body. From a report: Scientists, though, have never been certain what the appendix used to do -- and if it is still, in fact, useless. On Jan. 9, a team of researchers led by scientists at Midwestern University Arizona College of Osteopathic Medicine published a review study proposing an answer: the appendix is a secondary immune function that both catalyzes immune cell responses and floods your gut with beneficial bacteria when they've been depleted. And it still plays that role, in a limited fashion, in human body function."We can function okay without it, but the appendix does provide some degree of immunity and beneficial bacteria,â Heather Smith, an anatomist and lead author of the paper said.