Science Friday - The Gurgling, Growling History Of The Gut

Episode Date: November 18, 2024

Despite advances in scientific research, the stomach remains a subject of mystery and intrigue. After all, it’s nearly impossible to ignore its gurgles and growls. Some cultural understanding of the gut has changed too—from an unruly being that must be fed and placated, to a garden ecosystem that is to be nourished in order to flourish.And if you’re a frequent listener of Science Friday, you’re familiar with the gut’s microbiome—the constellation of trillions of microbes thriving in our bodies. And that the stomach has some of the same neuroreceptors as the brain, which has earned it the nickname of the “second brain.”Ira talks with Dr. Elsa Richardson, author of Rumbles: A Curious History of the Gut and co-director of the Centre for the Social History of Health and Healthcare at University of Strathclyde in Scotland. They discuss the changing cultural and scientific understanding of the gut, including the discovery of the enteric nervous system and Victorian-era physician Sir William Arbuthnot Lane’s obsession with curing constipation.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Despite our medical advances, the gut continues to be a source of both fascination and mystery. It is an organ of the body which has resisted medical authority in interesting ways. It's Monday, November 18th, and you're listening to Science Friday. I'm sci-fi producer Shoshana Bucksbaum. You're likely familiar with the gut's microbiome, that constellation of trillions of microbes thriving inside of our body. bodies, and that our stomachs have some of the same neuroreceptors as our brains, a second brain, so to speak, and that gut feeling, it's, well, impossible to ignore. A new book explores not only how the scientific understanding of the gut has changed over time, but also its

cultural significance. Here's Ira with more. Dr. Elsa Richardson is author of Rumbles, the curious history of the gut. She's the co-director of the Center for the Social History of Health and Healthcare at Drathclyde University based in Glasgow, Scotland. Welcome to Science Friday. Thanks so much for having me on, Ira. In the book, you're right about not just the medical history of the gut, also its cultural history. How have the metaphors we use to describe the gut shaped our understanding of it? Well, I think that's what really got me interested in the gut as a topic. So I'm a medical historian by training, but my interest tends to lie in where medicine and ideas about health sit in culture. And what I noticed when I was looking into the history of digestion and looking

into the history of diet was how dramatically the metaphors we have used to describe, think about our stomachs, have changed over time. So my area of specialism is the 19th century, 19th century British history. And one thing that I found really odd in a way was the way that the metaphors then that attached themselves to the stomach were overwork. overwhelmingly negative. So I think today we tend to talk about our stomachs as, you know, these kind of beautiful, blooming gardens that have to be, you know, tended and carefully managed, you know, ecosystems within, maybe. Whereas in the 19th century, the metaphors and the language associated with the gut was much more confrontational. So, you know, you have physicians in the middle

of the century describing the gut as an enemy within as a foe that had to be conquers. You or this kind of irascible creature that lived within you, which, you know, you fed and you tried to placate and yet it still acted against you. You still gave you stomach aches and terrible pains. Many of the sources I was looking at and citing were, you know, from the medical community, were physicians who were talking about and describing the stomach using really florid language, kind of quite unusual imagery. You know, possibly some of the mystery of the gut It revolves around historically.

It was harder to study as compared to other body systems, right? Yeah, I think that's part of why the metaphors around the gut are so rich and so diverse. One of the reasons is that for so long, the stomach really remains something of a kind of medical mystery. When dissection became part of medical education, these dissection manuals would often describe the need to examine the stomach first, because it's the organ which will decay quickest, right? So there's this sense in which outside of the body, the stomach doesn't really make sense, or it doesn't make sense for very long.

Added to that, there is, throughout medical history, especially before kind of modern medicine, the gut is also so important to treating the body, to diagnosing disease and to managing health generally. So, you know, before we have antiseptics, before we have ways to anesthetize patients, opening up the body is a really dangerous procedure. That leads to the question of, you know,

what other interventions can you make into the body? And one of the major ones is through diet, right? It's through the gut. So the gut is both a way that the body's health can be treated and maintained. but it's also kind of diagnostic space. So many doctors would examine the feces for clues as to what was going on in the interior of the body. Yeah. And it still talked about having a microbiome that's healthy, right?

And your diet might be able to impact that. Yeah, absolutely. So part of what is so interesting for me is a historian of medicine about the stomach and about diet is that, it is an organ of the body which has resisted medical authority in interesting ways. So on the one hand, where there are other parts of the body where medical expertise is paramount, right? So you think about perhaps going to, let's say, a cardiologist and a cardiologist tells you, listen, you know, you have to take these particular pills in order to stop yourself from having heart attack. you would be relying on the expertise of that physician, right? And you would probably likely do what they say.

However, the stomach is this space in which there is a lot of kind of competing different forms of knowledge and competing forms of expertise. So you think about the way that perhaps, you know, you may see a nutritionist if you had particular gastric problems, but you might also look to forms of household wisdom, right? you might also look to, I don't know, the advice of your grandmother about what to, you know, what's good to eat and what's not. But we've had big advances in understanding the gut. And I'm talking about the discovery of the enteric nervous system, right?

That there are all these nerves down there. How was it discovered that we have this sort of mini brain there? Part of what is so interesting about the interic nervous system. And so I think must have been mind-blowing to discover at the time. It's not only that there are nerves down there, but it is also that it is kind of truly, in a way, a second brain in that what was discovered about the interic nervous system when it was mapped by physiologists in the latter part of the 19th century was that it's also able to think for itself. The interic nervous system can act outside of the central nervous system.

So I think part of what the interic nervous system might force us to question is exactly, you know, what kind of thinking different parts of the body you're capable of doing. Because obviously the interic nervous system and the gut don't think in the same way as the brain thinks. Right. But part of what this suggests is that there is a kind of cognition going on there. Yeah, because most of us are keenly aware of the connection, I think, between the gut and the brain. you get butterflies in your stomach, you have anxiety, stomach aches. That relationship between mind and gut has changed over time, hasn't it?

I mean, we sort of realized it, but now we know more medically or scientifically how that happens. I think it's absolutely changed over time. But what I find consistent through the history of the gut is that basically as long as we have been interested in the brain, or as long as we've been interested in the stomach, we have been convinced of a link between the two of them. So I think that modern science is doing wonderful work

in terms of mapping that connection. So through the interic nervous system, through the kind of neurons in the microbiome that you mentioned in the opening, also through the vagus nerve, that kind of direct highway between the gut and the mind. So there's a great deal of work being done just now in terms of trying to understand exactly what the kind of mechanisms are which facilitate that connectivity.

After the break, a Victorian-era surgeon's monomaniacal obsession with constipation and why throughout history women have been seen as being predisposed to gut issues. I know you're an historian of science, and I want to get into some history because it's fascinating. You write about a Victorian-era physician, Dr. William R. Bothnot Lane, who is obsessed with constipation and curing it. Tell me a bit about his work and his theory of the gut, and I hope I got his name right. So William Brothnot Lane is a fascinating figure. So he was an extremely well-respected surgeon working in London around the end of the 19th century in the beginning of the 20th century. He was at one point surgeon to the king.

So he is Sir William or Rothnot Lane, actually. Excuse me, I didn't mean to leave that here. Excuse you. He becomes obsessed in the latter part of the 19th century with the problem of constipation. And one of the reasons that he becomes so interested in this problem is because of the theory that's not his theory, but which was very kind of present in this period called the theory of auto intoxication. And so the idea of auto intoxication basically posits that, material, waste material, sitting in the bowel for too long, will begin to fester,

grow putrid, and begin leaking all kinds of nasty bacteria and toxins back into the rest of the system. So this is, you know, as you can probably tell, partly a product of the rise of bacteriology as a field, right? So like this is the language of kind of good bacteria and bad bacteria is also a product of a generalized anxiety in the latter part of the 19th century about the problem of kind of causativness, right? The problem of, yeah, not being able to go. And William Barthot-Layne suggested or perceived that this was, in fact, a much bigger problem than, you know, that physicians had previously acknowledged. And what he suggested was that all of these kind of toxins that he thought were leaking back into the body from the guts were

causing all kinds of problems. So he attributed things like infertility to auto intoxication, fatigue, muscle wastage, neurasemia, but also, you know, quite dramatically things like cancer. You know, the failure to empty your bowels, at least once a day, was something which he viewed as absolutely imperiling your health. He would advise his patients to modify their diet, to perhaps, you know, take up different forms of exercise. But in the most severe cases, he began removing clinical large sections of their colones. So either like chunks of colon, but also sometimes like full colonectomies in the most severe cases. And he performed hundreds of these surgeries, mainly on women, it's got, must be noted, towards the end of the 19th century

in the beginning of the 20th century, until finally he was pulled up in front of the British Medical Board and was eventually struck off British Medical Register. So he had this kind of quite dramatic kind of fall from grace, really, all because of this quite monomaniacal obsession with constipation. Well, I want to get into that part you said about women. I mean, you're right about how throughout history women have been seen as being predisposed to gut issues, right? Yes.

Why is that? I think it's a really complicated question. So, I mean, we think about the way that even, I don't know what it's like over in the States, but in Britain, medication, laxatives, but also things like yogurts with probiotics, which are meant to improve gut health, are really predominantly marketed at women. I didn't know that. So we live with that association today, and apparently, you know,

according to figures, women are more prone to constipation than men. Now, this may have a physiological cause. It may be that it's associated perhaps with the hormonal changes or menstruation. However, it might also be that women today just report are more willing to admit, perhaps, to being constipated than men are. But what is interesting is that throughout history, there has been this kind of quite sustained and kind of complicated connection between women and constipation. So when William my breath not learning is working in the 19th century, he suggests that part of the problem is a kind of female prudishness. around matters of the toilet. You know that what is happening

is that women have been raised in kind of stuffy Victorian households, that they are too proper, and that this is somehow kind of impeding their, you know, toileting regularity. What he also suggests, and what is consistent also throughout history, is this kind of connection

that is made between women's reproductive capacity and her digestive health. So for William R. Bethnal Lane, one of the ways that he worries his female patients is by saying, look, if you are constipated, this is going to impact, one, your ability to get a husband. Okay, so you will have, according to him, sallow skin and be of a kind of, you know, crabby disposition, much less likely to get wed. But also that even if you are able to, you know, somehow bag a man, you will be unable to bear children

because this kind of this constipatedness in your system is going to impact your reproductive health. I only have a few minutes left, but I don't want to let you go without talking about one of the weirdest pieces of research in your book is about how what's in your stomach relates to what we dream about, really? That came out of a survey which was conducted by the British cheese board, boom boom, which suggested that, eating certain types of cheese before bed would produce particular kinds of dreams. So, you know, Red Lester causes weird dreams. Bree invokes kind of, you know, celebrities to appear in your dream. This was a survey that was undertaken in Britain. Probably as a piece of kind of, you know, wild marketing material.

Right. But it did speak to a quite long-standing association between the belly and the dreaming mind. The research that I looked into more closely was looking at the way that medieval dream theorists and dream interpreters talked about digestion. And these dream theorists proposed that a number of things could happen. So one, food digesting in your belly could send up vapors to your brain, which would then produce particular kind of dreams or visions. And based on that, they suggested that, you know, dreams that were had.

in the early part of the morning were more likely to be of a spiritual or kind of divine nature than dreams which were experienced in the early part of the evening, let's say. And the reason for that was that by the early morning, your stomach would have digested all of the food that was in it. There would be nothing sitting there festering anymore. And that therefore, these kind of, your dreams would not be clouded by these vapors emitting from the same. stomach. Now, obviously, we don't tend to think about dreams in exactly those terms anymore, but I think we still sustain some connection between perhaps having, I don't know, overindulged the night before, and then suffering kind of weird nightmares or terrors. Yeah, I remember when

I was a kid, my mother would say, don't eat all that, you're going to have nightmares. Yes, yeah, absolutely. When you go to sleep, I don't think there's any empirical evidence that's connecting any of these dreams to food, is there? A folklorist. by the name of Caroline Oates, has done some research into tracing the cheese dream, but the cheese dream across cultures. So in Britain and North America, we are very likely to report that after eating a strong piece of cheese, we have weird dreams, let's say. Whereas in other countries, namely southern European countries, so thinking of France,

Italy, places like that, people do not tend to report any association between having eaten, you know, kind of cheese and having a weird dream. And those countries are not known as kind of cheese avoiding nations, right? You know, without postulating exactly what that tells us, I think that part of what it describes is the way that, yeah, that dreams and the dreaming mind cannot sit outside of culture. Well, in this case, the cheese stands alone, as we used to say. Dr. Richardson, thank you for taking time to have to be with us today. And good luck with your book. Thank you so much for having me. It was a real dream.

Dr. Elsa Richardson, author of Rumbles, the curious history of the gut. And she is the co-director of the Center for Social History of Health and Healthcare at Strathclyde University based in Glasgow, Scotland. That's all the time we have for today. Lots of folks help make the show happen, including Felissa Mayors, Danielle Johnson, Beth Ramey, Jason Rosenberg.

Tomorrow, ticks are thriving in part due to invasive plant species. Plus, scientists recreate an ancient bird brain. I'm sci-fi producer Shoshana Bucksdown. Thanks for listening. We'll catch you next time.