For generations the appendix was thought to have no purpose. But now, researchers say they have discovered the true function of this organ, and it is anything but redundant.
Conventional wisdom used to claim that this small pouch protruding from the first part of the large intestine was simply redundant or an evolutionary shadow of a once useful organ. For years doctors advised people have their appendix removed and in spite of it’s now-apparent use, most seem none the worse for having it removed.
Duke University Medical Centre in North Carolina researchers say that following a severe bout of cholera or dysentery, which can purge the gut of bacteria essential for digestion, the appendix acts as a reserve for good bacteria to emerge.
In spite of the findings, Professor Bill Parker says that this does not mean we should cling onto our appendices at all costs.
“It’s very important for people to understand that if their appendix gets inflamed, just because it has a function it does not mean they should try to keep it in,” he explained.
“So it’s sort of a fun thing that we’ve found, but we don’t want it to cause any harm, we don’t want people to say, ‘oh, my appendix has a function’, so I’m not going to go to the doctor, I’m going to try to hang onto it.”
Nicholas Vardaxis, an associate professor in the Department of Medical Sciences at RMIT University, says that the theory put forward by the Duke University team makes a lot of sense.
As an idea it’s an attractive one, that perhaps it would be a nice place for these little bacteria to localize in, a little cul-de-sac away from everything else,” he weighed in.
The thing is that if we observe what’s been happening through evolution, the higher on the evolutionary scale we are and the more omnivorous animals become, then the smaller and less important the appendix becomes and humans are a good example of that.
“The actual normal flora bacteria within the appendix, as well within our gut, are the same, so we’ve lost all of those specialized bacteria.
“So it doesn’t have that safe house type of function anymore, I don’t think.
“It’s a vestige of something that was there in previous incarnations, if you like.”
Scientists were led to the discovery by examining the appendices of koalas. Unlike the short human variety, the koala is famous for having an extremely long appendix.
This aids in their diet which is almost exclusively made up of eucalyptus leaves.
Professor Vardaxis says that in spite of the fact that the human appendix acts in a similar manner to that of koalas, it is unlikely that we will see a shrinking of the Australian marsupial’s organ any time soon.
“Unless of course we have a massive blight and we get the eucalypt on which the koala thrives dying, then we may find some mutant koalas out there perhaps that will start eating other things, and as they start to eat other things, then over generations and hundreds of thousands of years of time, then surely, yes, the koala’s appendix will shrink as well.”
Professor Vardaxis says that the human shrinkage of the appendix was due to changes in our diet that took place over many thousands of years. Still, it is possible that any species with a larger appendix now, could find themselves in a similar situation if their diet were to significantly change, and their appendix began to shrink. Koalas, Vardaxis explained, might be afflicted by appendicitis and have to have it taken out at times, just like humans.