Appendix is lost its function millions of years ago?

Appendix usually treated as a body part that lost its function millions of years ago. All it seems to do is occasionally get infected and cause appendicitis. 

Yet recently it has been discovered that the appendix is very useful to the bacteria that help your digestive system function. They use it to get respite from the strain of the frenzied activity of the gut, somewhere to breed and help keep the gut's bacterial inhabitants topped up. 

The appendix is not a vital organ and medical researchers still debate its exact function in our bodies. One hypothesis suggests that it is a vestigial remnant of a once larger cecum. This larger cecum would have been used by vegetarian ancestors to digest cellulose from plants. Supporters of this hypothesis therefore conclude that the appendix no longer serves any purpose for us.

Another hypothesis suggests that the appendix acts as a storage area for beneficial bacteria during times of illness. Beneficial bacteria living in the appendix could survive being flushed out of the large intestine by diarrhea. The appendix would therefore help a person to recover more rapidly from illness by enabling the bacteria to re-colonize the intestines after the illness has passed.