How Replaceable Are You?

In the 1970’s TV show called Six Million Dollar Man, a test pilot is in a horrible accident. The show’s famous line goes, “We can rebuild him. We have the technology.” Now, in the 2025 book, Replaceable You https://www.maryroach.net/replaceable.html, science writer Mary Roach explores how people have collectively lived up to the task of rebuilding human bodies when they fail, as well as all the ways we may not quite be there yet. In this episode Regina G. Barber https://www.npr.org/people/1082526815/regina-g-barber and Mary Roach https://www.maryroach.net/maryroach-bio.html discuss three chapters of the book, get into everything from iron lungs to private parts and try to answer the question, “How replaceable are you?” Interested in more science behind the human body? Check out our episodes on synthetic cells https://www.npr.org/2025/10/13/nx-s1-5527869/life-synthetic-cells-engineering-alive and thefirst pig kidney transplant https://www.npr.org/2024/12/20/1220579294/pig-kidney-transplant-genetics. Email us your question at [email protected] mailto:[email protected]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:18Speaker 00

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• 0:23Regina Barber?

  When I was younger, I was excited to get older. And not just my 20s and 30s, but maybe even my 60s and 70s. At the time, the Golden Girls were cool, I loved science, and I thought if any part of my body didn't work anymore, it could probably be replaced. My heart, my lungs, my legs. But I recently read a book that made me think again. It's called Replaceable You by nonfiction author Mary Roach.

• 0:52Speaker 02

  Fairly far along in the process of writing this book, I was like, is there anything that we humans have built or designed or cooked up that is 100% perfect or pretty much just does what the original part does? And I thought, OK, the tears, how about tears? Have we got a perfect artificial tear? You know, I found this guy who works for Tear Lab, and he spent decades working on tears, and we got on to a Zoom call. And I said, OK, so artificial tears? He's like, yeah, they'll help for an hour or two, but they kind of wash away the good stuff. So we don't even have, we can't really even replace tears.

• 1:38Regina Barber?

  So my cyborg dreams may not become a reality just yet. But science has still made huge progress when it comes to fixing the human body when it fails. And Mary covers a lot of that progress in her book, from hair to pig organs to her experience visiting a burn unit at a hospital in Boston.

• 1:55Speaker 02

  Third-degree burns are really tough because the cells that would regenerate from below, like on a second-degree burn, those are destroyed. So the body tries to heal by contracting, by kind of pulling like a drawstring. But there are ways now to culture the person's skin off-site. So rather than waiting for the place that you took the skin to heal, so you can take more skin, you can take a biopsy and they can grow out these very thin layers of the person's own skin. There's spray-on skin, which you're spraying cells over the wound area.

• 2:34Regina Barber?

  Today on the show, how replaceable are you? We join Mary Roach on her adventure through the human body and learn how far we are from going full cyborg. I'm Regina Barber and you're listening to Short Wave, the science podcast from NPR.

• 2:55Speaker 00

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• 3:33Speaker 00

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• 4:17Speaker 00

  compared to renewal price, Ford in Florida.

• 4:21Regina Barber?

  So Mary Roach, we're going to focus the rest of this episode on three chapters from your book. We're going to start with the lungs. You write about the history of the human lung and the invention of something called the iron lung, which was particularly important during the polio epidemics in the 1940s and the 1950s. And for someone who doesn't know, polio is a disease caused by a virus that can lead to paralysis, including chest paralysis. So patients can no longer breathe on their own. And the iron lung helps with breathing. How does the iron lung work?

• 4:53Speaker 02

  People think about ventilators and they think about, you know, when somebody is intubated and put on a ventilator, that's a system where you're kind of just blowing up, you're forcing air under pressure.

• 5:07Regina Barber?

  Like a balloon.

• 5:08Speaker 02

  Like a balloon, like you're blowing up a party balloon. So you're forcing air into the lungs. But we don't breathe that way. Breathing is a very, it's a very natural state of affairs where your muscles are expanding, the muscles of your diaphragm and your rib cage, they open out the area. So they're lowering the pressure. So the air rushes in. And the iron lung works the same way. It's called negative pressure ventilation.

• 5:38Regina Barber?

  But you actually went in an iron lung. What was that like?

• 5:40Speaker 02

  I did. I did. I was in an iron lung. And it is, I mean, I haven't been on a positive pressure ventilator, which is a whole, I mean, most people are sedated when they're on them. So I can't compare it. But I will say, your breathing feels the way your breathing does when you're not in an iron lung, except that you have absolutely no control over when you're going to inhale and when you're going to exhale.

• 6:05Regina Barber?

  Wow.

• 6:06Speaker 02

  The machine has taken over.

• 6:07Regina Barber?

  Yeah.

• 6:08Speaker 02

  So if you're trying to talk with somebody, and this is something, I mean, I know that you're, when you speak, you're speaking on the exhale. You can't speak and inhale. I just tried to do it. So that's what happens.

• 6:20Regina Barber?

  Wow.

• 6:21Speaker 02

  So, you know, I would be talking to this guy whose iron lung I was... In and I would try to just talk normally and I, you know, it just cuts you off.

• 6:32Regina Barber?

  Wow, that's cool.

• 6:33Speaker 02

  Which is a weird, yeah, is kind of a weird thing. So it's, it's this very relaxed, kind of luxuriant breathing. But the other thing about the iron lung, your head is outside and it has to be a tight seal. So you have this thing around it, kind of like, so you're simultaneously breathing in this very luxuriant way and feeling like somebody is choking you. Cause it has to be, it has to be a tight fit.

• 6:53Regina Barber?

  Right.

• 6:54Speaker 02

  Not, it's not choking you, literally, but it is a tight, it's not, um, it's not a comfortable way to spend the night and I thought, I'm gonna sleep in the iron lung.

• 7:03Regina Barber?

  Did you last the whole night?

• 7:04Speaker 02

  I lasted about seven minutes.

• 7:08Regina Barber?

  We started talking about this with, like, now we have this kind of like ventilators, you said, like blowing up like a party balloon.

• 7:15Speaker 02

  Yes.

• 7:16Regina Barber?

  How does that compare to the iron lung? Is it, is it much, much better? Are there pros and cons? Like, what is the difference?

• 7:24Speaker 02

  Yeah, for sure. Well, a positive, you know, positive pressure ventilator, you've got to intubate the person. So, you know, you've got to thread this tube down and it's going through the voice box and it's, so you can't talk, you can't swallow. But what can happen with a positive pressure ventilator is you just, like with a party balloon, you know how the top part inflates easily and the bottom part doesn't? So you can end up with the lower part of the lungs not taking in the air and people tend to be sedated. And when you're sedated for a period, I mean, it's fine for a short period of time, but if you're, if you're sedated on positive pressure for days and weeks,

• 8:08Speaker 02

  then you start to get sometimes cognitive issues, um, muscle, muscle deterioration.

• 8:14Regina Barber?

  Wow.

• 8:15Speaker 02

  And it takes a certain amount of rehab to get you, you know, back to, to a place where you can breathe on your own and move around well on your own. So, uh, so you don't want to be on a, a positive pressure ventilator for extended period of time. But people who were in iron lungs, they were in there for. Weeks, months, you know, I mean, a lot of you, people in them would often regain some muscle control so they'd be able to get by during the day outside, but then they'd sleep in the iron lung. So they weren't always 24/7.

• 8:48Regina Barber?

  Yeah. So we're going to talk about the next chapter, the vagina dialogue. This is the chapter that focuses on vaginas made from parts of the intestine. Like, and I hadn't heard of this surgery before, and I was like fascinated that using the colon could create this like new organ. What is the process like and why the colon?

• 9:09Speaker 02

  Yeah, this was a chapter where I was just fascinated by the body's kind of adaptability. So what you can do is the colon, well, when you think about it, it makes a lot of sense. You know, it's tubular, it's moist, it's pink, it's stretchy.

• 9:23Regina Barber?

  Yeah, that's, that's what you said in your book, that that's a doctor was like, yeah, okay, makes sense.

• 9:28Speaker 02

  I can't think of any other body part that would do double duty as a vagina. I was talking to, he's the, Dr. Garcia, he's the head of the Cedar Sinai Transgender Surgery and Health Center. And this is a technique that is sometimes used if a more, the more common way of building a vagina doesn't work out. It's, it's an option. It's not used, it's not used all that often. You can take, you know, an eight inch, six or eight inch section of the ascending colon, you know, make a cut and you're going to stitch back the pieces of the colon, right? So that it's still a working

• 10:05Regina Barber?

  Yeah.

• 10:05Speaker 02

  tube, but you can keep, but you can swing down this section that you've liberated and you keep it attached to the blood supply, right? It's got a, you know, long enough connection to the blood supply. You can swing it down and stitch it in place and, and there you have a vagina.

• 10:23Regina Barber?

  Yeah. So this chapter, it kind of led you to this other realm of like replaceable. I'm just going to say it, penises, and you traveled to Georgia.

• 10:33Speaker 02

  Yeah.

• 10:34Regina Barber?

  To pursue this like story you had heard about of like middle fingers being used to rebuild penises. What kind of research is happening in Georgia? What happened?

• 10:44Speaker 02

  Well, let me tell you.

• 10:47Regina Barber?

  Okay. Fascinating.

• 10:49Speaker 02

  This came up, I was having a conversation with a, she actually does, she's a stem cell researcher, but somehow in the course of the conversation, she mentioned she saw a paper about a technique.

• 11:01Speaker 02

  Whereby a man's, um, the man had had cancer. Uh, and, uh, his penis was rebuilt using his middle finger. I, of course, imagined the finger removed and installed, pretty much as is.

• 11:15Regina Barber?

  Right.

• 11:15Speaker 02

  You know, with the nail. So I was determined to, uh, talk to this surgeon who is, uh, I found out in Tibaleesi, in Georgia.

• 11:27Regina Barber?

  The country, the country, Georgia.

• 11:29Speaker 02

  The country, yes, the country. And I wrote to him in English, in Georgian, using Google Translate. God knows what that note said, in Russian. Uh, I didn't hear anything.

• 11:39Regina Barber?

  Especially talking about replacement penises.

• 11:40Speaker 02

  I would love to see, actually, the, uh, how that actually read to somebody who speaks Georgian. So I went there and, uh, I showed up. The surgeon wasn't there, apparently on vacation. And I'm like, but we've come all the way from America. To which the logical response would be, well, you're a couple of idiots. But I was able to talk to another surgeon there who kind of showed me the, um, images of the procedure. Uh, it's not as is. It's, it's wrapped in skin.

• 12:13Regina Barber?

  It's not just a finger on a body.

• 12:16Speaker 02

  I don't know why he chose to use the finger. Uh, but I will say the penis, at the after photo, it looked quite normal. Except that it does actually bend at the knuckle. In order to show how strong it was, I get this. Um, there's an image of the penis kind of bent upward partway along. And there's a ceramic water pitcher being held by the penis.

• 12:42Regina Barber?

  That was the funniest part, I think, of that chapter for me.

• 12:44Speaker 02

  The ceramic water pitcher.

• 12:46Regina Barber?

  This is so great. Um, so after working on this book, like, in your opinion, what, what does the future look like for, like, transforming the human body? Is, am I gonna be a cyborg? Cause I would really like that.

• 13:01Speaker 02

  Hmm, not yet, Gina, but it'll happen. I mean, it'll happen. Uh, all these things are on the way. Same with bioprinting. I spent time at a lab, a bioprinting lab, the Feinberg Lab at Carnegie Mellon, which is doing really cool stuff. But I said, so how far are we from printing an organ that can be implanted and ready to go in a human being? And he said, we're kind of at the Wright Brothers stage, if you want to compare it to aviation.

• 13:34Regina Barber?

  I see.

• 13:34Speaker 02

  Which is both really exciting. I mean, the Wright Brothers, my god, they got the thing off the ground and down to the end of the pasture.

• 13:42Regina Barber?

  Yeah.

• 13:42Speaker 02

  Pretty cool. But a long way off from, you know, thousands of flights going back and forth every day.

• 13:51Regina Barber?

  Thank you so much for talking to us today and sharing this book with the world.

• 13:56Speaker 02

  Oh, thank you, Gina. It was so fun to talk to you.

• 14:02Regina Barber?

  If you liked this episode, give us a follow on the platform you're listening to us from. You can also check out our episodes on synthetic cells and the first pig kidney transplant. We'll link to those episodes in our show notes. This episode was produced by Rachel Carlson and edited by our showrunner, Rebecca Ramirez. Tyler Jones checked the facts. Kwasi Lee was the audio engineer. Beth Donovan is our vice president for podcasting, and I'm Regina Barber. Thank you so much for listening to Shorewave from NPR.

• 14:37Speaker 03

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