Purpose of Appendix Believed Found

CambodiaSam sent in this story, which opens: "Some scientists think they have figured out the real job of the troublesome and seemingly useless appendix: It produces and protects good germs for your gut. That's the theory from surgeons and immunologists at Duke University Medical School, published online in a scientific journal this week. For generations the appendix has been dismissed as superfluous. Doctors figured it had no function. Surgeons removed them routinely. People live fine without them. The function of the appendix seems related to the massive amount of bacteria populating the human digestive system, according to the study in the Journal of Theoretical Biology. There are more bacteria than human cells in the typical body. Most are good and help digest food. But sometimes the flora of bacteria in the intestines die or are purged. Diseases such as cholera or amoebic dysentery would clear the gut of useful bacteria. The appendix's job is to reboot the digestive system in that case."

Re:Polio, Asthma & Allergies

[paleo2002]

I have studied (some) biology, especially from an evolutionary perspective. There are aspects of our immune system that deal with macroscopic threats - parasites, foreign bodies, etc. In modern, industrialized society intestinal parasites and unremoved splinters aren't really a problem so a part of our immune system is left with very little to do. Like a bored child or pet, our immune system goes looking for something to do. It overreacts to pollen, proteins in common foods, and animal dander.

With the proliferation of antibacterial products, I worry about two things. In the short term, what kind of new allergies will people develop as chemistry continues to replace people's immune systems? In the long term, what kind of backlash are we going to see when microbes begin to develop some sort of resistance to alcohol and other antibacterial agents?

Re:Reboot?

[eldavojohn]

Is the digestive system a computer?

Perhaps a better term might be 'repopulate' although it doesn't sound as trendy.

I suppose you could poke equally as much fun back at the computer science community with:

Virus? Is a computer the immune system?

Fields of science borrow and share terms all the time. People seem to like the term 'reboot' despite it's origins being found in computers [wikipedia.org]. I myself sometimes forget the pure origin of the word. The 'boot' part being from the bootloader of a system which plays a vital role in the bootstrapping process prior to the start of the operating system (if there is one installed). Do you think tailors are annoyed that we stole their bootstrap word?

Why nitpick terminology when everyone borrows it. Accept descriptive words, don't be prescriptive--I think that's what makes languages fun and interesting instead of boring, dry & dead.

"produces"

[Gothmolly]

Just like leaving meat out in the sun "produces" flies? Didn't we sort all this out back in the 17th century or whatever? Oh wait, its CNN, that paragon of quality journalism.

Re:Evolution would have gotten rid of it

[Belacgod]

Incorrect. Evolution would have got rid of it if it was actively detrimental. The human body has plenty of useless-but-neutral features--earlobes, for one--that won't go away.

Evolution doesn't approach the best solution, just the solution that's better than the others in existence at the time.

Re:Evolution would have gotten rid of it

[tomhudson]

>"Evolution would have gotten rid of it if this part were useless."

Evolution takes time. Hence the darwin awards [darwinawards.com]

Also, its a "moving target", since evolution alters the environment (predators, food chain, etc.), one consequence is the current "solution" is always sub-prime.

another body part that is often yanked

[Skapare]

From TFA:

The theory led Gary Huffnagle, a University of Michigan internal medicine and microbiology professor, to wonder about the value of another body part that is often yanked: "I'll bet eventually we'll find the same sort of thing with the tonsils."

And what about the foreskin?

Re:Evolution would have gotten rid of it

[nurb432]

Evolution will drop useless parts as well, just not as quickly since it doesnt effect survival at the time. ( where it may have at some point in the past ). Remember too, mating rituals are part of survival. Often in the animal kindgom if you arent as pretty as the competition you cease to contribute to the gene pool. Lobes and other apparent useless-but-neutral features may have been a 'pretty' factor 10 thousand years ago for us.

And since evolution never stops, you cant really predict when something like earlobs will disappear. It just hasn't happened YET.

Re:Keeping kids healthy

[Loke the Dog]

2 and 3 contradict each other. One says immunization by exposure to bacteria/viruses is good, the other says its bad. Admittedly, sterile needles have replaced dirty fingers for the last century. But I don't see why the old method was better than the new one.

Re:Evolution would have gotten rid of it

[bwen]

Your not-inconsiderable portion of the population is considerable - about 7%. Appendicitis does kill often if left untreated. Delay in diagnosis is the principle reason for mortality so to "chop" it off at the first sign of inflammation is usually a good idea. Spontaneous resolution of appendicitis is not something to wait for. Having a patient perforate in front of you is considered bad medicine in the US. If it does serve the purpose of protecting the bowel flora during bouts of cholera / dysentery, then it probably is superfluous in a developed country and will be selected against (esp in fertile women as appendicitis usually strikes people between 10-30.) I do wonder if it is able to salvage more bacteria when faced with antibiotics and if it helps repopulate the gut in developed countries after a pt takes a Z-pak or fluoroquinole for their "bronchitis."

Appendectomies save lives

[cryfreedomlove]

Please don't read this and think that you or your loved ones should avoid an appendectomy if you need one. Nearly all appendectomies are performed on painfully sick people who are facing certain, slow, painful death without an appendectomy.

Re:Polio, Asthma & Allergies

[irtza]

thank you. If I had mod points, I would boost you up and call it a day.

Part of what evolution teaches is a thing called "Selective pressure". If there is no pressure, then functionality is lost. For example, species that adapt to caves tend to go blind because destructive mutations to the eyes pose no greater survival risk.

The same is true for the lower classes vs middle vs upper classes as mentioned in parent. As sickle cell, thalessemia, reactive airway diseases become more treatable, their prevalence will increase or at least come to a steady state. This will also allow other diseases or complications of these conditions to manifest. An example of this would be side-effects of anti-retroviral agents. They can be quite devestating in some cases, but does that mean we stop prescribing them? You can only justify that if you - like Hitler (I thank thee Godwin for this one) - feel that the weak should die to strengthen the gene pool.

Many people are opposed to the idea of going on hemodialysis or getting an organ transplant. They site examples of people doing poorly on these therapies - about the amount of time they spend in the hospital - about the slew of medications they are on. One must bear in mind that these complications are far better than the alternative - a short miserable existence.

Look at the life-expectancy of the lower classes vs the middle class and you will see that hygiene has some significant advantages. Soap and antimicrobial agents are one of the few medical instruments that have had a great impact on the overall life-span of society. Most other advances barely left a dent in the overall life-span.

if someone says its better to have rampant cholera and dysentery wiping out huge populations of children - potentially doubling or tripling infant mortality - just so we don't have as much appendicitis, I would question their judgement greatly.

As for air purifiers (mentioned somewhere in this thread) - they possibly prevent interstitial lung disease on top of removing allergens.