Appendix’s purpose: A new idea surfaces

Added duties: A team of researchers at Duke University think they've found the purpose of our appendix: to produce needed germs for our digestive track to help break down our food.
Added duties: A team of researchers at Duke University think they've found the purpose of our appendix: to produce needed germs for our digestive track to help break down our food.
All during college, I had this irrational fear each time finals week would roll around that I would be struck with appendicitis. It never happened and to this day, I still have that little bugger jiggling around down there by my intestines.

And if this group of researchers is correct, I should be glad I still have it. A team of scientists at the Duke University Medical School thinks its found the purpose of the appendix.

That little dangler found between the end of our small intestines and start of our large intestines could be producing good germs for your digestive system. Our body actually uses bacteria to help digest our food. And if we lose too much of it, the researchers surmise, the appendix produces and kicks in a new batch of bacteria to help us keep breaking down our food.

Chew on this stat for a second: there are more bacteria than human cells in our bodies. Most of that bacteria is good and works in out digestive system to process our food.

This new news flies in the face of the long-held idea that the appendix had no current purpose. Some scientists figured that it was a leftover from some bodily function that humans had evolved out of over the years. Doctors routinely snip it out when doing other surgeries in the area to prevent the patient from the chane of suffering appendicitis. The most recent figures, from 2005, from the Centers for Disease Control and Prevention report that 321,000 people in U.S. where hospitalized for the condition.

The new theory figures that the appendix can regenerate bacteria after too much of it is lost by the body. Severe intestinal problems like cholera or amoebic dysentery can completely flush a person’s body of all of its digestive germs.

In our more diverse culture of today, we actually don’t need out appendix as much because we’re exposed to many “good” germs on a regular basis, the scientists postulate, with us picking them back up, if we need them, from other people around us. That has made our appendix less needed.

Helping back that idea up are statistics that in less developed countries, where an appendix is still very useful, the incidences of appendicitis are much lower.

Other medical researchers not connected with the study say the idea seems credible.

And we should all still be worried our appendix if it starts to hurt. If they become inflamed, it can be deadly with about 300 to 400 Americans dying year because of the condition.

Your Comments, Thoughts, Questions, Ideas

James's picture
James says:

Some will take this as proof that what was once considered a vestigial organ has a purpose. But there was never a doubt that the appendix at one point served a purpose, nor does the recent proposal suggest that this purpose continues to be an essential one for humans in modern societies in our time. In short, this study is interesting, but it would be inappropriate to treat it as though it has some evidenciary weight either against evolution or in favor of intelligent design.

posted on Tue, 10/09/2007 - 10:37am
Karl Bates's picture
Karl Bates says:

I posted a polite correction for two serious errors on this posting two days ago and notice it hasn't appeared.

Here goes again:

1. The appendix doesn't "produce" bacteria. The hypothesis here is that it acts as a safe haven for beneficial bacteria to ride out a storm of diarrhea without being flushed away. After the illness is over, they emerge and repopulate the gut.

2. The Duke team has not argued that it is "cultural diversity" that accounts for the difference between the appendices of industrialized nations and those of the underdeveloped world, it's sanitation. Where food and water are clean, there is less call for protection from purging dysentery and sometimes the restless appendix and its specialized population of immune system cells causes trouble. By contrast, in the underdeveloped world where diarrheal disease is still the leading cause of childhood deaths and a major health problem, appendicitis is quite rare.

As an NSF-funded source of public science information, I would think you'd want to correct the misperceptions you've created here. Here's the original press release from Duke Medicine, with no mention of "production" or "cultural diversity."

posted on Wed, 10/10/2007 - 2:38pm
Liza's picture
Liza says:

Mr. Bates:

Thank you for your feedback.

I want to address your second concern first. The comment that you posted two days ago DID appear on the website as recently as yesterday afternoon. (I read it, and referenced it while on the phone with another blogger.) Despite that, it seems that your comment was somehow tagged as "spam" (though it obviously isn't), and deleted. We're taking steps to be sure that the same thing doesn't happen again.

It is very important to correct mistakes wherever we find them, and I'm glad that you've pointed out the errors. Science Buzz allows any registered member to post stories, and any user to comment on them. That means we have to trust our community of readers to be careful and responsible when writing stories, and we count on the community's vigilance to correct mistakes. And you did.

We also encourage our bloggers to follow information back to the original source, and to provide a link. Thor didn't do that in this case. Without speaking to Thor, I can only guess that this was an honest mistake, and that he got his information from a newspaper article, such as this one, or this one from the AP, both of which make the same error about producing bacteria. I can't explain the confusion over "diversity;" without knowing his source, I can't say if Thor misunderstood something or simply repeated an error from another source.

In any case, the correction is posted. We're glad to have it. And we appreciate your interest.

posted on Wed, 10/10/2007 - 3:52pm
JG's picture
JG says:

"A storm of diarrhea!"

Ha Ha! Indeed!

posted on Wed, 10/10/2007 - 4:13pm
AK Dano's picture
AK Dano says:

What about some modern procedures that also flush a lot of bacteria out of our systems? I recently had my first colonoscopy, yuck, I turned 50.
Since the exam, I have had poor digestion, bloating, etc. What do you think about the possibility that since I have no appendix anymore the required system flushing before the exam may have upset the bacteria balance?
I have heard of several folks encoutnering similar difficulties either after lower GI, colonoscopies or after a series of antibiotics. Appendix connection? It's interesting.
Thanks for posting the information!

posted on Sat, 10/13/2007 - 10:51am

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