ANDREA SEABROOK, host:
Here's the test of your grade school education. What comes to mind when I talk about your appendix? Are you thinking useless intestinal pocket? Evolutionary throw back? Or I bet this is the one - vestibule(ph) organ? Well, that's what we all learned, but we might all just be wrong.
Dr. William Parker at Duke University joins me now. Hello, sir.
Dr. WILLIAM PARKER (Assistant Professor, Experimental Surgery, Duke University Medical Center): Hello, Andrea.
SEABROOK: Well, isn't the appendix a useless vestibule organ, Dr. Parker?
Dr. PARKER: That was the thinking for a log time. We've just found what we believe though is the function for that organ, or it's not even really an organ. It's sort of a structure that sticks off the colon.
SEABROOK: And what is it's purpose? What's it's use?
Dr. PARKER: In a nutshell, we think the use has to do with maintenance of - in preservation of the good bacteria that live in our body, those bacteria that we need.
SEABROOK: What does that mean - good bacteria?
Dr. PARKER: Well, everybody has in their intestines a lot of bacteria, billions of bacteria that are helping us digest our food and helping us keep away bad bacteria. We need those bacteria and our immune systems have ways of protecting that bacteria in facilitating growth of that bacteria.
SEABROOK: And so how do you prove a notion like this? What did you then go do?
Dr. PARKER: It's very difficult to prove this kind of thing.
Dr. PARKER: And the reason that it may be very difficult to prove Is that we don't think that you really need the appendix in a westernize culture with modern health care and modern sanitation practices.
SEABROOK: Oh. So that's why people aren't crippled by not having their appendix.
Dr. PARKER: In fact, that's one of the things that made it very difficult for people to know what the appendix was for is because in theory, if we're right, then you really don't need it anymore. And, in fact, when we tell people, well, we figured out the function of the appendix almost in the same breath, we have to say that, you know, if it gets inflamed, please, you know, get it taken out because it's life-threatening if you don't.
SEABROOK: Why wouldn't we need it though? I mean, even now there are packing special yogurt that gives you good cultures. I mean, don't we need those good bacteria still?
Dr. PARKER: You do need your good bacteria but the idea behind the appendix it's a more of a reserved supply. It contains the same bacteria that the rest of your gut contains under normal circumstances. But if you get, say, amoebic dysentery or some kind of E.coli that's very dangerous and all of your bacteria gets contaminated, so they get flushed out…
Dr. PARKER: …well then way back up in the corner you can have this little safe pocket in the appendix and those bacteria then are occasionally extruded in and can restart the population after everything else has been flushed out. And fortunately, we don't have those kinds of epidemics in our country anymore. We might have a little outbreak here and there, but it only infects, you know, a few people. So as a whole population, our bacteria are still very intact.
SEABROOK: Dr. William Parker teaches experimental surgery at Duke University Medical Center in Durham, North Carolina.
Thank you, sir, very much.
Dr. PARKER: Thank you very much, Andrea. It's my pleasure.