What Does the Appendix Do? Shining New Light on an Age-Old Question

What does the appendix do? When facing this question, scientists have long used the terms "redundant" and "useless," telling patients that it's simply a remnant from eons ago that human development never got around to eliminating or an organ that only occasionally become infected with appendicitis, requiring removal. But now, scientists know that your appendix actually has a purpose.

According to a study by Duke University and other research by Midwestern University Arizona College, that pinky-sized appendage that sits near the juncture of your large and small intestines now evokes a new sense of purpose. And it all has to do with bacteria.

What Does the Appendix Do?

Your body has trillions of bacterial microorganisms, and many are found in your stomach and intestines. These are good bacteria, and their purpose is to help break down the foods you eat and stave off the growth of bad bacteria -- the kinds that make you sick. These good bacteria also play a critical role in producing vitamins and hormones needed by your body.

Before modern-day medicine and public health, people suffered from cholera or dysentery. Both diseases share the common symptom of severe diarrhea, emptying literally everything out of your gut -- including the good bacteria. Although not definitively proven, research solidly points to a new theory. It suggests that the appendix acts as a safe house for good bacteria. After intense diarrhea, the appendix repopulates and reboots the intestine with good bacteria before harmful bacteria finds a home there.

Humans aren't the only creatures with an appendix; about 533 mammal species live with an appendix. Scientists believe an appendix developed 30 separate times in different species over the ages, and once it appeared, it almost never disappeared.

What About Appendicitis?

In the so-called "hygienic" societies of a developed world, your immune system isn't challenged daily by parasites or disease-causing organisms. With no need to function regularly, the appendix may become blocked or overreact when asked to perform its duty, causing inflammation and appendicitis. Commonly, a surgeon removes the appendix and your life returns to normal. People without an appendix may take longer to recover from an intestinal infection, but in today's world, medicine can supply the protection that an appendix offered in the past.

The march of science continues, and the question of what the appendix actually does seems to have reached a satisfying conclusion for now. Perhaps the lesson to learn here is that no matter how small or insignificant something seems, almost everything has a purpose -- it just hasn't been discovered yet.