Published 23rd June 2022

Our ancestors’ diet: Surprising discoveries from a 5,000-year-old iceman

Why would a podcast on nutrition and health run an episode on a mummified man found in the mountains of Italy? Have we gone completely off track? We haven’t, we promise. 

It turns out this unfortunate soul could be the key that unlocks an entirely new understanding of human health. This mummy, discovered in an alpine snow drift by two hikers, gives us a remarkable understanding of how we lived 5,000 years ago.

New technologies have allowed scientists to examine every inch of him — from the contents of his stomach to the health of his arteries and even his gut bacteria. Together, this provides a remarkable glimpse into the surprising dietary choices of our ancestors.

In this podcast, Jonathan discovers some secrets held by our ancestors by speaking to two outstanding guests:

Frank Maixner works at the Institute for Mummy Studies in Italy and travels the world uncovering the secrets of our ancestors.

Tim Spector is a co-founder at ZOE and one of the top 100 most cited scientists in the world.

If you want to uncover the right foods for your body, head to joinzoe.com/podcast and get 10% off your personalized nutrition program.

Transcript

[00:00:00] Jonathan Wolf: Welcome to ZOE science and nutrition, where world-leading scientists explain how their research can improve your health.

Why would a podcast on nutrition and health run an episode on a mummified man found in the mountains of Italy? Have we gotten completely off track? We haven't. I promise. It turns out that this unfortunate soul could be the key that unlocks an entirely new understanding of human health. This mummy discovered in an Alpine snowdrift by two hikers gives us a remarkable understanding of how we lived 5,000 years ago. New technologies have allowed scientists to examine every inch of him, from the contents of his stomach to the health of his arteries and even his gut bacteria. Together, this provides a remarkable glimpse into the surprising dietary choices of our ancestors.

The story of this discovery is a lot of fun and we're joined by an incredible guest to help tell it. Frank Maixner has one of the most exciting jobs in the world. He works at the Institute for Mummy Studies in Italy and travels the world, uncovering the secrets of our ancestors. We're also joined by Tim Spector, my co-founder at ZOE and one of the world's top 100 most cited scientists to help us understand the implications of these discoveries for our health today.

Frank and Tim, thank you for joining me today. And I have to say I'm very excited to have a mummy scientist on the podcast. I'm sure that like many of my listeners, you know, as a young child, I was obsessed with Egyptian mummies and the idea of doing something.

And now we get a real mummy scientist to talk to. And so why don't we start at the beginning of this story in modern times. And Frank, can you tell us about what happened? I think about 30 years ago, high in the mountains, you know, between Italy and Austria. 

[00:01:57] Frank Maixner: Yeah, it was in 1991, actually. So there was this couple from Nuremberg, Erika and Helmut Simon.

They were on holiday and they were on a hike in the mountains, on the Alpine ridge between Austria and Italy. And it was quite late, already on that day. And then they need to take a shortcut back to the hut there. And when doing this, they stumbled over a body, which was still sticking half in the ice. And they immediately thought that this maybe is a hiker or skier who died up there and they informed the hut owner and he informed the Italian police, which then not very responsible for this.

And they then said the Austrians would take over this case and, yeah, this body was recovered and it was for a long time, not considered precious. It took some days actually until an archeologist had a look at this finding and it turned out that it was a 5,300-year-old mummy who died up there. And this was the start of this research on the Iceman, actually.

[00:03:02] Jonathan Wolf: So they've discovered this 5,000-year-old body sort of sticking out of the ice at the top of the Alps. Who was he and what happened to him? 

[00:03:13] Frank Maixner: It's a good question, actually. So some things we do not yet know. Who he was, actually, this would be a nice question to ask him but it became more and more clear that he belonged to the so-called early European farmers which already lived the settled lifestyle. They had access to domesticated animals and plants also. Yeah. He lived and grew up also in the Italian Alps. Eastern Italian Alps. 

[00:03:39] Jonathan Wolf: And tell us a bit about why he ended up stuck in this glacier and then a bit about what we've been able to discover about him, because I think this is one of the most amazing things, and this is a podcast only. So you can't see the pictures, but you know, it's amazingly well preserved. And I think the story of what we've been able to figure out is extraordinary. Help us to understand that a bit, Frank. 

[00:03:59] Frank Maixner: Yeah, the mummy and this finding were particular for archeology, also. Normally you do not find any organic material anymore, and this is really special.

So all the equipment which we found with the Iceman was very particular, but also the mummy with the preserved tissues provided a lot of interesting insights. For example, radiographic imaging revealed that actually Iceman murdered up there. So they found arrowheads still sticking in his left shoulder.

We saw also that he had a lot of calcification in his arteries, for example. So he suffered from atherosclerosis and the most important also about it, which we are dealing with now, currently is also that biomolecules are preserved in such mummies. So this means we can still analyze the original endogenous DNA or the proteins, and we can confront this data with modern-day data. So this is a very particular information source, I would say. 

[00:04:57] Jonathan Wolf: So, this is amazing. This is the oldest unsolved murder case in the world. Is that right? Frank? That you're working very CSI. 

[00:05:05] Tim Spector: True cold case. 

[00:05:07] Jonathan Wolf: Thank you, Tim. So, how old was he? What do we know about his lifestyle? And obviously, on this podcast, we're fascinated by what this could tell us about diet and nutrition. Have we been able to figure out anything about this? 

[00:05:22] Frank Maixner: Yeah, anthropologists think he is around 40 to 50 years old, was a very slim guy, very trained, hiked a lot. You see this, that he was hiking a lot in the Alps and we noticed that he was most likely hunting up there, hunting wild animals, which are present in this region, like the ibex or the red deer, for example.

And yeah. Definitely was part of this community, which was in this kind of transition from hunter-gatherers to settled lifestyle. And this is a very fascinating period because there are a lot of changes in diet also happening. 

[00:06:02] Jonathan Wolf: And so what have we been able to discover about what he was eating? 

[00:06:07] Frank Maixner: We were lucky because normally mummification if it's not starting immediately, the degradation of the body starts in the intestinal region.

And here this mummification stops this and we have still access to the intestinal contents, the stomach content, and also the lower intestines. And by analyzing this. We, not only microscopically, but also molecularly could see that he has eaten ibex meat actually, of this mountain goat, red deer meat. And in parallel, this was supplemented by cereals and an ancient form, the einkorn wheat, actually, it was part of his meal. And interesting was also the discovery of a toxic brake fern, which definitely was also part of his meat but we have not yet can really identify why he has eaten this. So maybe in a young form where it's not so toxic. So it was composed of these parts.

And a second thing, which we see is 50% nearly was then also fat. So it was a very lipid-rich, very fatty, rich diet to get the energy he needs up there. So this was another observation we had. 

[00:07:13] Tim Spector: Wasn't there something about the type of meat that was fatty meat, rather than the lean bits. I remember reading something about that. Can you remind us how that deduction was made, that they ate the fatty bits, the meat, not the lean bits? 

[00:07:26] Frank Maixner: That's true. So it was definitely intentionally simple that the regions where the fat is more enriched and this ibex, for example, normally the meat is quite fatless or not rich in fat, but certain regions like in the neck or other regions, you have quite accumulations of fats and, the Iceman took these parts and used it as his diet also. So it was most likely air dried, also. And we can imagine that it's in the form of a spec or in a form of an air-dried fat meat consumed. For weeks, they hunted together and they needed to of course, also to conserve and preserve this meat. And the best way to do this is really to air dry it.

[00:08:07] Jonathan Wolf: So this was sort of the ultimate high density, high-calorie food to allow you to exist in a pretty tough environment. And I guess part of the reason why this amazing information existed is that when he died, it was already so cold? Is this why the whole mummification gave you this sort of data, you know, right down to the food that was still in his gut?

[00:08:26] Frank Maixner: That's also our assumption that he was then subjected to a so-called most likely freeze drying process, similar to lyophilization a little bit. So it's not that he was just covered by snow or ice, but in parallel, also the drying process then conserved the biomolecules and all his tissues, actually. 

[00:08:46] Tim Spector: Okay, isn't this what Californians pay, for to live forever?

[00:08:52] Jonathan Wolf: I hope they prayed for a different outcome, Tim. 

[00:08:55] Frank Maixner: But maybe this is, they look similar afterward. 

[00:09:00] Jonathan Wolf: We don't recommend this at home just to be clear. And I guess what's surprising. So I think already Tim's picked up on this idea of the meat, and I think you talked a bit about the fact that we were actually able to look at the health of his arteries. Could you just explain a bit, because we often talk about everybody being completely healthy in this sort of ancient times? And I think actually you've got some quite surprising results, didn't you? 

[00:09:23] Frank Maixner: Yeah. That's actually really an interesting discovery talking about these, maybe modern-day diseases, like atherosclerosis. 

[00:09:30] Jonathan Wolf: Which is furring of the arteries. Isn't it? That can lead to heart attacks. Something like this. 

[00:09:35] Frank Maixner: Yes. And he has really severe calcification already of his arteries, also in the heart region already. And this a little bit stands in contrast to his lifestyle because he was slim. He was really hiking a lot. In the diet, you can, of course, argue, that now we have a snapshot only in the stomach content. We have seen a lot of fat actually, but this, maybe it's just an exception. But the interesting thing, look also at other mummies from different regions like South America, also Egyptian mummies, we see always 30% to 40% of these mummies also suffer the same level of cardiovascular diseases or calcifications actually.

So our assumption is that we see this also in the Iceman that there's a major also component coming from our genes or their genes. And the Iceman has actually a high genetic predisposition to develop this kind of disease. And this is also in other mummies, which show already the signs. And this seems to be independent of the diet, the origin, from the population you belong to. And I think this brings us away a little bit from this, this is only a modern-day disease linked to our lifestyles. I think we should also not forget this. 

[00:10:48] Tim Spector: And just remind us how we think he is? 

[00:10:51] Frank Maixner: The Iceman's 40 to 50 years. 

[00:10:53] Tim Spector: All right. So it was an early middle middle-aged man. So normally be quite unusual, even in modern times to have heavy calcification of the arteries without it being genetic.

So the genetic theory might be the one rather than diet or lifestyle related, given that he had some other diseases we don't know about, but that seems most likely. 

[00:11:14] Jonathan Wolf: And so I would be quick, would I to tend to say, cause I think one of the things that is sort of coming through a lot of our work, right, is that animal fat, in particular, is one of the low-quality fats.

So I think I might've gone with this assumption that he's eating a rather unusual diet probably for this time, very high in this, and that this is linked. But I think what you're both saying is that that's not enough really to explain this. 

[00:11:34] Tim Spector: I think so. And I think it's, we don't really know what his habitual diet was.

Cause he might've been having a high-altitude hunting type guy. And wherever he came from, they might've just been eating einkorn all the time. You know, there's a sort of standard wheat if he was, because he's not quite a hunter-gatherer and we don't know which he favored, I guess. Before we move on. I do remember hearing something about Iceman having magic mushrooms on him.

Can you confirm that rumor? 

[00:12:03] Frank Maixner: Yeah, he has a recorded first aid kit with him, so he carried also mushrooms. One is to facilitate making a fire. So this is a particular mushroom, which is then facilitating this fire-making process. But the other mushroom is actually quite interesting. So this is one which we think he could have used also for medications or like a medicine, which he'd carried with him. And we see also some signs that he bit into it. So this is also very interesting. What then the reason was for this, we don't know, it's known that this mushroom also stops bleeding. If you put it on a wound, it can help to cure this. And it has some bacteria acidic also in action but the real reason we don't know it, actually. 

[00:12:51] Tim Spector: Okay, but it wasn't a hallucinogenic mushroom, as far as we know. 

[00:12:55] Frank Maixner: No, it's not hallucinogenic. It's not. 

[00:12:58] Jonathan Wolf: Seems like a dangerous thing to be taken at 3000 meters, I feel so, probably a good thing. 

[00:13:04] Tim Spector: And then falling into a crevasse. That's right. 

[00:13:06] Jonathan Wolf: Yes. So we've talked a bit about the diet and I think that's already amazing that we can understand this, but you and your colleagues have managed to go further. Right? And actually understand the bacteria, the microbiome that he had 5,000 years ago. 

[00:13:22] Frank Maixner: This was actually also in cooperation with Nicola Segata's group and others, which are focusing on modern gut microbiomes, actually. What we saw there is that the Iceman still carries these traces of the gut microbiome community.

And that we can confront this also in communities we know from modern people. And this was quite surprising to see that he resembles, not the gut microbiome we most likely carry in us, but more than one, which indigenous populations also still carry nowadays. So populations which have more traditional diets, which have a different lifestyle to ours.

So we call it also non westernized populations and the Iceman was the first time also the proof that these non westernized, populations, maybe a good proxy, how the gut microbiome of our ancestors was. 

[00:14:13] Jonathan Wolf: So, this is really amazing. We basically have this ability to look back 5,000 years and understand the microbes at that point. And, 5,000 years is a lot of time for us. It gets from microbes that are potentially, you know, having another generation, every 30 minutes is like some unimaginable number of generations. What was the most surprising thing that we found out when we look at the microbiome?

[00:14:35] Frank Maixner: Yeah, there's a difference nowadays. And this is what you said already 5,000 years seem to be not long, but within these 5,000 years, there seem to be changes going on. We do not yet understand well when this happened, but there was clearly a higher diversity of microbes in the Iceman. So. strains we nowadays do not carry anymore in our guts.

Were present in the Iceman. Shifts of this gut community, which we see. And this is actually very surprising that within this very short timeframe, we see diversity decay similar to the case in diversity in plant or animal kingdom. So, this potentially can be linked also to some other developments, diseases we can nowadays know, are linked to diet, maybe. And when does decay, or when this diversity change happened, this we are now currently investigating, actually. 

[00:15:27] Jonathan Wolf: And Tim, can you explain a bit for us what this diversity means? 

[00:15:33] Tim Spector: Yes. Diversity is a way of microbiologists generalizing, a very complicated picture of our gut microbes into something that most people can understand.

It's the way of saying how many different species there are in all the trillions of gut microbes in the average gut, you know what that community looks like. And so a highly diverse gut microbiome, Is one, a bit like a garden where there are lots of flowers of all types flowering, and the soil is incredibly rich and there's hardly any room for weeds to grow.

It's a very healthy community with one species helping another, and it just looks beautiful all year round and has a non-diverse gut microbiome, it looks more like an Arizona backyard with dust bowls and toxic waste and other things going down.

[00:16:26] Jonathan Wolf: Yeah. I'm not sure everyone in Arizona is going to like this particular position. 

[00:16:29] Tim Spector: Okay. Not all gardens and Arizona are like that, but I've just envisioned a more desert, thing where there are a few sparse plants that have adapted to that rather rugged environment. And there might be cactuses and things like this. So it's that large contrast. You've got to bear in mind visually how you might see your gut microbes.

And we know that people with nearly all the common diseases we're seeing today in westernized societies, which don't happen in non westernized societies, such as diabetes, such as obesity, such as auto-immune diseases, cancers, heart disease, et cetera. And the thing with chronic inflammation, plus even mental disorders such as depression, autism, and spectrum disorders, all have a reduced diversity compared to the healthier types of Western society.

So we sort of generally links this number of species with health in a very broad sense of it. 

[00:17:30] Jonathan Wolf: And I understand Frank that he is an Italian, which we obviously know means that clearly had a very good diet. Right? That's the general view and not an Austrian. Is that right? Frank? Is that the conclusion? 

[00:17:41] Frank Maixner: Yeah, he was found 90 meters on the Italian side. So the Austrian border was 90 meters away. So he's definitely Italian. And the diet of course tells us also that he liked to eat the Italian diet. That's true. 

[00:17:56] Jonathan Wolf: So I think this discovery sort of started a whole new academic discipline, right? Looking at our ancient ancestors in a lot more detail and with all of these new techniques that were possible.

And in particular, my understanding is that the science has really expanded in the last few years to not just look at mummies in general, but actually to look at mummified poop, or I think paleofeces is I think the technical word if you want to sound smart at a dinner party and you're really at the forefront of this. Can you tell us a bit more about why? And I think particularly really interesting to talk about your big investigations in the, how's that salt mines in Austria and in these caves in Mexico. 

[00:18:36] Frank Maixner: Yeah, it's exactly how the search of having more science for this kind of diversity and to also investigate more the diet of our ancestors. And for this, we need different kinds of samples, and materials, where also this biomolecule preservation as well as in the Iceman.

And they are, these paleofeces are actually very well suited. So we were also surprised how well preserved plant material, but also then DNA or proteins are in these materials. So they have a similar kind of preservation. So they got desiccated very rapidly or water just wasn't removed. And then they are in a similar state like lyophilized sized.

And this is either due to the positioning of this cave in Mexico, where we analyzed paleofeces material, which is in high altitudes, very dry conditions and the same holds true for this other side in Austria, where salt mining is done and in the salt mines, also rapid desiccation takes place of all organic material. And this then leads to this extremely valuable preservation.

[00:19:41] Jonathan Wolf: And so how long have people been at the salt mines? And so how far back have you gone and then tell us, what did you find. 

[00:19:48] Frank Maixner: Yeah, it's a very unique site, I would say. So I was there two weeks ago. So you have to drive there for hours and hours because it's in the middle of nowhere. It's around 1000 feet, 400 meters attitude.

You have snow there until May, snow again from September on. So aside from where you normally would not expect a high culture developed, a European culture, the so-called Eichstatt culture, which is part of the Iron Age, we are talking about 2,500 years ago. And they all were there because they had access to the sword. So the sword was for their own purposes, but they also traded the sword. And since then there was a continuous salt mining going on until nowadays in, an industrial scale actually. And it is an interesting culture. So they were working hard in the mines, but they had in addition, due to the salt, very rich grave goods, they had access to different dietary components like wine from the south.

They had ember, they had gold, and they had ivory from Africa. So we see really a long trade network here, including also trade networks of exotic foods. For example, walnut was not present at the time in Europe. 

[00:21:02] Jonathan Wolf: So tell us, what did you find about what they were eating through this? 

[00:21:06] Frank Maixner: The analysis tells us that these miners actually, similar to the Iceman had a quite fibrous diet, again, a carbohydrate-rich, different kind of cereals, a mix of cereals actually, which is interesting.

So we have the wheat, spelt and we have the emma, we have einkorn again also as Tim mentioned, but also the barley was present all the time. Then a form of cereal, the millet, was more present at that time also. So we have quite a rich carbohydrate, rich diet, which was supplemented by proteins from the broad bean, from the garden bean also.

And on top of this, there were also animal products consumed such as meat from the swine or kettle meat, or kettle blood products with particular in one sample, a high presence of blood. This means also this very important protein, rich slaughter byproduct was actually used for consumption and was actually a rich energy source. 

[00:22:08] Tim Spector: Just like current Austrian sausages, like blutwurst. Is that right? 

[00:22:13] Frank Maixner: Yeah, exactly. This was one of the ideas also that they really already use this combination. And you need also for certain of these clogging processes, high salt concentration. So they would have had the possibility to combine the salt and this blood and enhance the blood processing. 

[00:22:31] Tim Spector: And evidence of preserving meats, friended style, like salamis or hams and things, or not?

[00:22:36] Frank Maixner: Yeah, they not only traded the salt, but as you said, Tim, it was really a network of different products and they also traded, and one of them was also ham. And we found here a lot of bones from swine and then also archeological manufacturer, also oils where they actually then salted the meat. They also process the meat and conserve the meat. And this is not only for their own purpose but also for trading this product. 

[00:23:05] Jonathan Wolf: So they were eating a lot of different things. It sounds like Frank, how plant-based was the diet? Cause he started talking about a lot of different, you know quite complex grains. Then we started to talk about quite sophisticated meat techniques. How plant-based were they in comparison to our Iceman, you were talking about before? 

[00:23:19] Frank Maixner: Yeah, it's hard to say how much finally this made up. But it was very carbohydrate rich for sure. A lot of cereals, as I said already. And sometimes we find also white plants like the apple occurring. Also, some greens, and some berries also, which they supplemented their meals. 

[00:23:39] Jonathan Wolf: And what about dairy, which is a topic that people often talk about being this sort of modern introduction and you're going back 2,500 years. Was there dairy at this point or not? 

[00:23:49] Frank Maixner: There were already dairy products present. This we know also from other sites. So not only the domesticated animals were used for meat production, but dairy products were used. And we see this also on that side. So we have indirect evidence also here using the DNA that they already produced cheeses, and not only produce cheeses, but also flavored these cheeses.

This was a very surprising finding, in my opinion, since we did not expect that they had really interested to change the texture or the taste of something like this cheese. And we saw here that they produced a kind of blue cheese actually, which we nowadays know, like the Roquefort or the Danish blue. And so they are similar cheeses, like the gorgonzola. And this was one of the most surprising findings actually here. 

[00:24:36] Jonathan Wolf: So they were making their own Roquefort 2,500 years ago up in the mountains in Austria. Have they managed to recreate this? I feel that Tim would be first on the list if they were re-growing this. 

[00:24:47] Tim Spector: Ancient salt, mine cheese. Yeah. I think that would be a big hit, particularly if you took, yeah if you went in there and got all the microbes off the rocks and things, I'm sure you could make a really fascinating cheese. I think we should definitely start a company though. To annoy the French to say this is the original Roquefort. 

[00:25:05] Jonathan Wolf: So, I mean, I think one of the things that's interesting about this is, you know, do you ever think about my, my own sort of history with food in the past.

I've given a lot of things up. With a sense that like particular foods are bad for me. And I'm trying to sort of deal with intolerances or thinking about my health. And I guess what's interesting is you're showing this really big diversity of foods, both these cases, these were obviously quite rich individuals.

And, and is that also something that you see across all of these examples? When you look at Mexico, for example, do you see this very different story? 

[00:25:35] Frank Maixner: It's definitely depending on the society you're looking at. So this is something we see now. So this is how should, as you said, a very rich community have access to sophisticated foodstuff, I would say. So it's very rich and also exotic, traded, also plants, for example, in these paleofeces from Mexico, for example, we don't see this diversity also. So there are mice. There are, also plants which were growing there. They were no meat products. So far we discovered...

[00:26:04] Tim Spector: sorry, just to clear up, they weren't eating mice. Maze, you mean, is that right?

[00:26:09] Frank Maixner: Maze, sorry. 

[00:26:11] Tim Spector: Might've been eating mice and rodents again, don't try that at home.

[00:26:15] Frank Maixner: That's an important difference. 

[00:26:17] Jonathan Wolf: So you were saying actually, basically this is an entirely plant-based diet that you were seeing in Mexico? 

[00:26:22] Frank Maixner: Yeah. Thanks a lot, Tim. This was important. Yeah. Yeah. I'm actually much less diverse diets or all of them had access to plants and plant diets and no indications for animal components in this diet. So quite different societies for sure. 

[00:26:40] Jonathan Wolf: We've talked about diets, but I think you've also been able to look at the microbiome of these different groups. Isn't that right, Frank? And what have you seen there? 

[00:26:47] Frank Maixner: Like Tim before said we see here a diversity, we nowadays do not see often in our westernized communities and this is not only true for these very ancient samples we analyzed, but in the Eichstatt Saltman, for example, we have a sample which comes from the modern times. So we are here in the 18th century. When Mozart, for example, was in Salzburg and performing, and, we are in the Baroque period, actually it's called, and this sample shows the same, like the Iceman, like this Mexican, like this. Bronze Age or Iron Age H samples, the same community structure. And of course, it's not one sample and we need to extend this also, but this brought us to the conclusion that most likely we are having also other factors, which came during industrialization, for example, which were much more severe affecting also this gut community structure, so that not only diet but also other factors are important to consider.

[00:27:47] Jonathan Wolf: So that's quite cool. You might have Mozart's grandfather's stool sample is what you're saying, is that right? You know what his microbiome is, and you've, maybe, we have an inkling now maybe on Mozart's microbiome. And what you're saying is it's a lot healthier than ours. This is the key that you're saying, Frank, is it that, just making sure I'm understanding this right. This microbiome actually looks more similar to something 2,500 years ago than actually to mine, which is not so great, or even Tim's who, you know, in the Western world is supposed to have a pretty good microbiome. You really see that shift. So recently? 

[00:28:18] Frank Maixner: That's exactly what we see. So of course, as I said, it's one sample now, as we are now trying, and this is a nice thing on this site, it's really that we have access to a lot of these samples so that we can also use a lot of samples, which are even more recent. We are talking about the 19th century or the beginning of the 20th century. So we can really now make this in a diachronic approach.

And we see maybe really, more signs when such shifts happened. So we always have to keep in mind, of course, that those people who were working in the salt mine, were hit at a particular site where they worked on. Maybe we cannot generalize it too much to everybody now, but yeah.

[00:28:57] Jonathan Wolf: I mean, Tim, maybe talk a bit specifically about sort of the microbe part of this. Frank's done this brilliant job explaining, like, beyond just changes in diversity, have we been able to understand more about particular bugs and you know, where is the science in terms of understanding what's changed between the, you know, what would have been in my guts, you know, 200 years ago and where I am today?

[00:29:20] Tim Spector: Yes. Well, I will say it's very complicated. So are thousands of different species, some strains have disappeared, some haven't, and it's hard to know which ones to focus on because there are so many, but I think a lot of the scientists are focusing on a few that we do know what their functions are. There are a couple that is mentioned. One is about Prevotella coppery which is found in nearly all non westernized populations in large amounts and in only a small proportion of westernized populations or individuals, I should say. So it does vary within one population. You might have it. And Frank might not, you know, it's highly variable.

[00:29:57] Jonathan Wolf: Unfortunately, I don't have it, but yes. Thank you, Tim. 

[00:30:00] Tim Spector: It's related to general good health and having less metabolic syndrome and less inflammation. And so trying to understand what's happened there, is really important because these certain microbes could in the future be used as probiotics as treatments or given to you when you have medicines or anti-cancer therapies, et cetera.

To understand the exact type. It's not just the broad species, but the exact subtypes. Could also be really important. And that is some of the things that have changed. We might've kept the general species, but we have a very different strain from our ancestors. That's really important. So Prevotella is a really important one because of its role, particularly in inflammation and the immune system.

And another interesting one that which only came to light again with the work of Nicola Segata's lab that we've been working on with the ZOE samples, has highlighted just recently in the last few weeks that this parasite, which five years ago, we used to send to a doctor to get eradicated with antibiotics is present in all westernized populations called blastocysts.

So we all had it. The Iceman has it, it was like completely ubiquitous, blastocysts this parasite. And it was thought this was bad for us. And so eradicated when it was found, but it hasn't been hard to detect until, the latest genetic sequencing, which we found in the ZOE predicts samples, but it turns out only 25% of the UK population has it, and it's more common in men than women, so fewer women.

But amazingly, when you go to the US samples, it's less than 5% have it. And so we're even seeing within Western populations really big changes in this and, what's really fascinating is this parasite is actually good for you. It's associated with having low body weight, better metabolic syndrome, fewer glucose responses, less internal fat, and lower blood pressure.

So it's quite amazing when we've now looked at nearly 15,000 samples across the world. And this is proving like a, a real barometer of westernization, if you like, and must be related to, you know, not only the environment but also diet. And so I'm really lucky because whatever reason I've still got it, I'm not quite sure why. Maybe it's my Australian mother. Gave it to me. 

[00:32:31] Jonathan Wolf: If I sort of pull this all together, I think one of the things we'll always try and do in this podcast is talk about what does this mean for us today? And what's the actionable advice. So I think it's this amazing story and insight is so much fun, but if I can't just go and get these microbes today and I can't buy them in the store, what's the actionable advice that comes out of this, do you think? 

[00:32:51] Tim Spector: I think learning that when non westernized populations have better sets of microbes means that we should be generally thinking about reducing our antibiotic intakes, particularly for our children who generally have 18 courses of antibiotics by the time they're 20, certainly in the US and in most Western countries, so, we're overusing antibiotics, which is one reason that we've probably killed off a lot of our microbes, not being too sensitive about sterilizing everything and making sure that our children, particularly when the microbiome is really most responsive, given the chance to be outdoors and have trees and eat dirt and play with animals as our ancestors did. And then finally, you know, improving our diets so that we don't pollute it with highly processed foods, and chemicals, and that we try and eat up a rich diversity of plants and try and learn some of the lessons from our ancestors.

I think that to me is the take-home message. We don't have all the answers, but I think there are some sensible things we could start to do now that would try and reverse some of this really bad trend in our biology. 

[00:34:03] Jonathan Wolf: And Frank one other takeaway, it seems to be from your research, which is really interesting is, that there isn't just one ancient diet. Is that a fair conclusion? 

[00:34:12] Frank Maixner: I fully agree with the Eichstatt for example, samples, we had four specimens so far, one of these individuals really ate blue cheese and drank beer. The others do not. So this is already a good example. There's quite a variation between these different diets.

[00:34:29] Tim Spector: I like that guy. 

[00:34:31] Frank Maixner: But it's also interesting, in a respect of, does this reflect maybe different social status. So this is really something we want to investigate more. So is this a more frequent phenomenon or is this more sudden? Yup. 

[00:34:47] Jonathan Wolf: I think also say this big variation, it sounds like in meat-eating this idea that we didn't need any meat doesn't seem true equally. Well, you're not really seeing anybody on an enormous exclusive meat diet. Is that also a fair takeaway from this? 

[00:35:00] Frank Maixner: Definitely. This is definitely linked to the availability, also food. And finally, we had now in Mexico, a very plant-based diet only, but most likely because it was a poorer also society. And then we have the Iceman. Which would have already accessed maybe two domesticated animals, but at that time they went back again and hunted animals also, and still stick to this omnivore's diet, having plant-based and animal-based diets. And this then continues in the salt mines. Also very, not only had a plant-based diet but also animal based diet. So this is something we see throughout, but it's always availability and access to this foodstuff, actually. 

[00:35:44] Tim Spector: So no evidence of a keto or carnivore diet. There were no fanatics for that, that you able to detect so far? 

[00:35:51] Frank Maixner: No, I cannot imagine that there was this kind of fashion already.

[00:35:55] Tim Spector: Omnivores. Yeah. That's everything.

[00:35:59] Jonathan Wolf: My one takeaway of this is this idea that you could just imagine this we're all built for this one diet that we all had in the past. That isn't really true because depending upon where you are living, you're talking about, you know, a variation from entirely plant-based to like surprisingly high and meat to other things.

And this, I guess, ties into the story we often hear about, you know, how our microbes themselves are helping us to adapt to these different environments. To try and wrap that up. I think we covered a lot of things and, I always try and do a little summary to try and pull it together. This is a challenging one this time, but let's see.

I think that we started by talking about this amazing story of the Iceman and about how modern science can now recreate the way that our ancestors lived 5,000 years ago. But for most of human existence, our diet was very different from what we sort of had over the last 200 years, that this was very varied in the past, but what we see is, critically that our gut microbes were very different in the past, Tim talks about them being much more diverse, many more species. And that actually, that seems to have continued until very recently. And this is very new information that just in the last, even 200 years ago, it looked more like hunter-gatherers today.

There are things that we can do to try and compensate for where we are today. And Tim talked a lot about things we can do with our children about less antibiotic usage and being able to sort of probably interact more with nature that in general, trying to improve our diet is valuable. And that we can't just say, there's this one diet in the past, actually.

You know, we saw this big variation, some people eat lots of meat, some people eat none. They were certainly eating cheese 3000 years ago. So we've been living with cheese for longer than I would've guessed and lots of fiber. So you talked a lot about these fibrous grains and lots of variety. And then finally, I think we may have lost some of the very best bugs, Tim.

And if I can pronounce this right, you mentioned both Prevotella and Blastocystis as two bugs. We're just starting to discover what could be really health promoting that were present in the Iceman. And although Tim has one of them, I know I don't have either of them. And so maybe that's something we can get back in the future, but today I guess we have to focus on diet. Is that right? 

[00:38:13] Tim Spector: Yeah, I think you've summed it up well. 

[00:38:15] Jonathan Wolf: Very good. Well, Frank, we will definitely invite you back as you discover more. And I hope that we will be getting you around the world to find these ancient paleofeces close to listeners on this podcast. That would be very exciting. I think many people engage with ZOE or are passionate about trying to push forward the science. Thank you both so much. I really enjoyed it. And look forward to speaking again, soon. 

[00:38:37] Frank Maixner: Thanks to you, Jonathan.

[00:38:38] Tim Spector: Thanks. Bye.

[00:38:39] Frank Maixner: And Tim also, yes. 

[00:38:41] Jonathan Wolf: Thank you to Frank and Tim for joining me on ZOE science and nutrition today. We hope you enjoy today's episode. If you did, please be sure to subscribe and leave us a review, as we love reading your feedback. If this episode left you with questions, please send them in on Instagram or Facebook, and we will try to answer them in a future episode. And absolutely do let us know if you believe there is one of these paleofeces in your neighborhood. Frank is serious about being willing to follow up on that.

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As always, I'm your host, Jonathan Wolf. ZOE science and nutrition is produced by Fascinate Productions with support from Sharon Feder and Alex Jones here at ZOE. See you next time.