The appendix plays a hidden role in gut health: shots

On the first day of spring break in Phoenix in 1992, 12-year-old Heather Smith was excited about her family’s upcoming ski trip.

But before Smith and her family could pack their snow pants, she realized she wasn’t feeling well. She said: “When she woke up, she felt a little nauseous, but we didn’t know why. During the day, she felt worse and worse and she started having pain in her abdomen.” she says.

By mid-afternoon, her father took her to urgent care. She ended up having emergency surgery to remove her appendix.

Smith still has a small scar from his appendectomy. And after her surgery, she found herself intrigued by the part of her body she had suddenly lost. “That got me wondering: Why do we have this weird little organ in the first place? What does it do? Why does it get inflamed?”

Smith He grew up to become a professor of anatomy at Midwestern University and editor-in-chief of the journal The Journal. anatomical records. And decades later, Smith made his mark in the field by researching the very organ that ruined his family’s vacation plans in 1992.

She acknowledges that the appendix has a bad reputation as a useless organ that can cause pain and require emergency surgery. “But recent research has found that it has functions that help us,” she says.

NPR’s shortwave We spoke to Mr Smith about the benefits of the appendix and how a future may come when appendicitis can be prevented and treated without emergency surgery.

This conversation has been edited for length and clarity.

What is the appendix and where can I find it?

A type of appendix found in humans, some primates, and rodents looks like a small worm. It is about the size of your little finger and protrudes from the caecum, the first part of the large intestine.

You can locate it based on a landmark called McBurney’s Point.Draw a line between the navel and the protruding part of the pelvis. [on the right]two-thirds down, that’s where the appendix is.

How did scientists get the idea that the appendix was useless?

There has long been much debate about what appendices do and whether they serve a function. [Charles] Darwin’s era.of [fact] That we can live without it lends some support to the idea that it’s a vestige and doesn’t actually do anything. Therefore, Darwin’s interpretation of it as a trace was reasonable at the time, given the information he had.

But thanks to modern technology, we can now see things like the microanatomy of the appendix and biofilms, and have a better understanding of what it is and what it does. I did.

How has the appendix evolved over time?

Mapping the distribution of the appendix across the phylogeny, or tree of mammalian life, can be interpreted as the actual existence of the appendix. evolved independently. It has emerged independently many times throughout mammalian evolution. That is, evidence that it must serve some adaptive function. It is inconceivable that the same type of structure would continue to appear unless it served some useful role.

So what useful role does the appendix play?

I found that this appendix has two related features. The first function is to support the immune system. The appendix contains a large concentration of immune tissue, which helps the immune system fight off anything bad in the intestines.

The second function it serves is what we call a safe house. This was the hypothesis proposed by the team of. Duke University in 2007. And they argued that the appendix may act as a safe reservoir for our beneficial gut bacteria.

When your stomach is not feeling well, or when you have diarrhea in which all the good bacteria in your intestines are expelled from your body, the appendix is ​​like a blind tube with a very narrow diameter and a narrow lumen. Bacteria are not washed away from the appendix. The idea is that it’s safe during this time of gastrointestinal distress and that it can leave the appendix and recolonize the rest of the intestine with this good bacteria.

So the appendix helps us in two ways in our intestines. Not only does the appendix help fight off invading pathogens, it also helps repopulate the intestines with this beneficial bacteria after gastrointestinal issues.

Why do some people get appendicitis?

Appendicitis occurs primarily in developed countries of the world, areas where diets tend to be low in fiber. One hypothesis is that low fiber content makes it easier for small pieces of food to become clogged during digestion. [inside] The appendix is ​​damaged, cutting off its blood supply and causing inflammation.

Another hypothesis, which seems less plausible these days, is related to an older idea called the hygiene hypothesis. The idea is that we’re over-sterilizing these days with all the antibiotics and all the antibiotics we take, so our immune systems aren’t developing properly. The reason is that the immune system is not developed properly. The reason is that the immune system is not developed properly. . This causes the immune system to overreact and panic. And because there’s so much immune tissue in the appendix, this is one of the areas where it shows up.

Will this new understanding lead to new treatments?

I think there are some promising treatments. With accumulating evidence that having an appendix can actually be beneficial to your health, people are researching ways to treat appendicitis with antibiotics and other methods without completely removing it. Research shows that you can get infected with some really bad, nasty bacteria. temperature difference This tendency tends to be higher in people who have had their appendix removed.

Therefore, there are health benefits to retaining your appendix. In an ideal world, there would be a future where we didn’t have to delete all the time.

What did you learn from studying this “weird little organ”?

I think this study showed me the importance of examining anatomical details. Anatomy may be considered a dead science because it is simply the study of the body. We may think we know everything about the body, especially the human body.

However, it turns out that there are many more variations, functions, and microanatomical adaptations that are not fully realized. Therefore, there is absolutely value in conducting descriptive studies of rare animals that have never been described before, or in observing small parts of our own bodies that are not well documented. .