Understanding - 8/21/2009 -
"Duke University Medical Center proposed that...the a safe haven where good bacteria could hang out until they were needed to repopulate the gut after a nasty case of diarrhea, for example." 
It is NOT "
a vestigial (antique/outdated) organ."  Darwin "was not aware that appendicitis, or inflammation of the appendix, is not due to a faulty appendix, but rather due to (a faulty diet & GI biome) cultural changes associated with industrialized society and improved sanitation. 'Those changes left our immune systems with too little work & too much time their hands, a recipe for trouble,' says Parker."
Medical Science
Dr. Edward Group III - - research from Duke University Medical Center suggests our gut health depends on function of the appendix.
Article -11/24/2015 - @
"The appendix may produce and protect beneficial probiotic colonies in the digestive system.
According to researchers, the human digestive system is full of
bacteria necessary to digest food. [1]
When attack from diseases, sometimes these important kinds of bacteria are purged or killed off.
In such situations, the appendix can act as a reserve for good bacteria. After the
immune system beats off the disease, the bacteria emerge and re-colonize the gut... According to research, lymphoid tissue accumulates in the appendix after birth. [2] In turn, the appendix helps in the maturation of B lymphocytes and production of antibodies. [3] Whatís more, the appendix produces specific molecules that aid in the movement of lymphocytes to various locations within the body. Based on current evidence, proposals have been made to suggest the appendix serves as a 'reservoir' for beneficial gut flora. When illness reduces good bacteria from the intestines, the appendix may store some of that good bacteria for back up. [4] Itís also been shown that individuals without an appendix may be 4 times more likely to suffer from recurrent Clostridium difficile colitis, an irritation of the large intestine by spore-forming bacteria. [5] This condition is often present when the body is running low on gut flora, potentially explaining the connection between the appendix & its role in maintaining probiotic levels.
The appendix still carries the potential for appendicitis, a common & serious appendix-related disease where the appendix becomes inflamed & can rupture. Appendicitis doesn't always result in appendix removal but it cannot be ignored. Studies from the Centers for Disease Control & Prevention found that around 300 to 400 Americans die from appendicitis every year.
McDowell, William - 10/13/2019 - +
An amoeba is a microorganism that enters the body & eats the brain.