Flutterby™! : appendix theory

A new theory on the function of the appendix, a paper from Duke University suggests that perhaps it's for storing good bacteria when the intestines are flushed from infection. But it also had this note about the possible hazards of too much cleanliness:

In less developed countries, where the appendix may be still useful, the rate of appendicitis is lower than in the U.S., other studies have shown, Parker said.