**EP347: What Do You Know About Your Appendix?**
**Dr. Auric Bishop:** Welcome, my name's Dr. Auric Bishop. I'm a cardiologist, an author, and a keynote speaker. I'm the CEO of the Healthy Heart Network. I'm all about trying to help people live as well as possible for as long as possible. Heart disease is huge in Australia. Every 20 minutes, someone suffers a heart attack. Most of these could probably have been avoided if only we knew what to do. This podcast is all about helping you understand blood pressure, weight, and cholesterol for better health. If you enjoy this podcast, I would be honoured for a five-star review. You can share it with your family and friends. It may well save someone you love.
**Dr. Warwick Bishop:** Hi, my name is Dr. Warwick Bishop, and welcome to my podcast and videocast station. Thank you so much for tuning in. Very quickly, if you happen to be tuning in from Botswana, I'd like to personally recognize you. Thank you so much for making me number three in medical podcasts in Botswana. I don't know how that came about, but I'm absolutely beside myself to have found that out just the other day. So thank you so much. For those listening in Australia, I'm dropping in and out of the top 100 medical podcasts in Australia. To be honest, I'd be super grateful if you could share this podcast or subscribe if you're not already, because I would just love to get its reach out there further and be more recognized. Having said all that, thank you so much for listening this far, and I hope you find today interesting. Well, I think I did, so I'm going to share it with you.
What I'm going to be talking from is one of the bits of medical news that go past me on a regular basis. This particular piece of work is from Medscape Medical News by Marta Zarasky from June 10 this year, and it's about the appendix and whether the appendix is useless or not.
Well, this is a super interesting article, and it really talks about whether we consider the appendix important or not. Often, it's considered in the setting of an emergency with abdominal pain and often in the situation where it's about to be operated on and removed for fear of rupture and the complications of that. But there is some emerging work that simple antibiotics could be an alternative therapy for appendicectomy, and that then raises the question that for an uncomplicated appendicitis that responds to therapy with antibiotics, should we be taking it out?
Well, there is a question that removing the appendix may well be linked to increased risk of such things as irritable bowel syndrome and even colorectal cancer. There are some emerging signs that there could be significant impact from removing the appendix to such a degree that it's not unreasonable for us to pause momentarily and think about whether we should be whipping it out without a trial of at least trying to preserve it.
There is a comparative anatomist from a Midwestern university in the States called Heather Smith, who really suggests that there's no reason to remove an appendix, as it is better to have one than not have one at all. This is interesting because way back in 1928, an American physician called Miles Brewer suggested that people who had appendicitis should be left to perish so as their inferior DNA, i.e., that DNA that allowed them to have an appendix, would be removed from the gene pool, calling them uncivilized people and candidates for extinction. Old Miles was hoping to see, if you like, evolution and natural selection weed out people with an appendix.
In fact, interestingly, even Darwin sort of suggested that it was a rather useless vestigial and leftover from us switching diets from leaves to fruits. Well, we'll come back to all that. Interestingly, as we start to look at the appendix in a different way, instead of it being a frustrating piece of anatomy, which is a blind-ended tube at the end of the colon, perhaps it actually has a role for other things.
The question evolves and revolves around whether it's important for maintaining gut microbiome and having an impact on the immune system. There is some suggestion that it does play a role in several medical conditions, from ulcerative colitis to colorectal cancer, to Parkinson's disease, and even lupus. This is significant because roughly 300,000 Americans will undergo appendicectomy each year. It is worth us trying to figure out whether it's important to try and keep it or not.
The appendix is a small blind pouch, a little sausage, if you like, that only has one end open to the colon, the other end closed, and it's attached to the large intestine, just past the junction of where the small intestine meets the large intestine. Interestingly, not all animals have one. It's been found in several species of primates and rodents, as well as in rabbits. It's in wombats, so there's an Australian flavour to it. Other mammals don't necessarily have one; dogs and cats, for example, don't.
Interestingly also, although the appendix looks like a big fat worm, it has different sizes in different animals. Looking at comparative anatomy studies, trying to understand how evolution has impacted the appendix, there appears to be at least 29 times throughout mammalian evolution where there's been some change in the function of the appendix, pointing to it having potentially, or quite reasonably, some adaptive function.
There was a French study where scientists looked at data from 250 plus species of mammals. These were all mammals in a French zoo. They discovered that those animals that had an appendix seemed to live longer. One possible suggestion was that the researchers suggested that an appendix may have a role in preventing diarrhoea. The same study looked at the records of 45 species of primates housed in the same zoo. Scientists established that the primates with appendices were less likely to suffer diarrhoea than those that didn't possess the organ.
So it might be that the appendix has a role in reducing bowel troubles. The opportunity to test this on humans is probably unethical, but nonetheless still gives us cause for thought. There was a study that compared people with an intact appendix with a history of appendectomy versus people with a history of appendectomy, and these were shown to have more than double the risk of developing serious infection with non-typhoidal salmonella, the type that might require hospitalisation. So a question about a protective role.
If you think about this little pouch that sits within the colon, you could quite reasonably ask if the appendix acts as a safe house for beneficial gut bacteria. Think of a severe infection that might completely clear out the gut. Maybe something like salmonella with watery diarrhea, no feces in the bowel, everything washed out. As the diarrhea clears out all that bowel, it takes with it the microbiome. Once the infection's over, however, one could theorise that the appendix acts as the, if you like, reservoir for the microbiome to re-establish the large gut and therefore re-establish a normal environment for that individual organism down the line.
So the safe house hypothesis for an appendix is pretty easy. Oh, pretty easy. Pretty reasonable to hold on to and certainly pretty interesting. The significance of that, of course, is losing your appendix through appendicectomy may well mean that if you are confronted with an infection down the line, you may not have the appendix to replenish the stocks of those healthy microbiological organisms in the gut.
It does seem that the appendix has a second function as well, and it may serve as a bit of a training camp for the immune system and picks up the environment, looking for markers where the immune system may well become activated. In fact, the human appendix is enriched in special cells known as M cells that act at detecting and capturing invasive bacteria and viruses and presenting them to the body's actual T cell immune system.
So if we dwell on the beneficial bacteria storage and the immune system, it may really explain why the appendix appears to be linked to various diseases. A Taiwanese study looking at people who'd undergone appendicectomy pointed to people having a significant increased risk of irritable bowel syndrome if they'd had their appendix removed, to such a degree that some authors have written that if you've had your appendix removed, you should be under surveillance for the development of irritable bowel disease.
Similar data seems to have linked type 2 diabetes with people who have had an appendicectomy, which is sort of interesting, and also an increased risk of lupus, particularly so in women. There's a bit of contention as well, and some of the links of appendicectomy include such things as Parkinson's, ulcerative colitis, and colorectal cancer, which I've touched on.
It is interesting to note that in a small study in 2019, the performing of an appendicectomy led to a third of patients improving their ulcerative colitis when the appendix was removed. So what's going on? It appears clearly to have some role in immune function. Where that sits, it's going to be hard to know. I think time will tell. Such things as colorectal cancer being linked with removal of the appendix will, I think, lead to more insight and observation around this space.
And it is interesting to note that when it comes to Parkinson's disease, there's a protein within the appendix called alpha-synuclein, which can accumulate in the brain and could be linked to early and progressive Parkinson's disease. But this has not been shown, and consistently it's been conflicting in different studies.
Where does it leave us? Probably if antibiotics can prevent us from having an appendicectomy, it might not be a bad idea to keep hold of it. It probably was put there for a reason. However, if we are going to use antibiotics to clear an appendicitis, i.e., treat the bugs that are inflaming the appendix, could that very antibiotic therapy alter the reservoir of good gut bacteria that the appendix is holding on to?
At this stage, I'm not entirely sure, but I had never really thought about the appendix before, and thinking about it as a reservoir for the gut microbiome, thinking about it as an immune modulator, I think are really fascinating thoughts, and I wanted to share them with you.
Well, I hope you found that interesting. Whether you've got an appendix or not, I do wish you the very best. I hope you live as well as possible for as long as possible. Take care and bye for now.
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