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Episode 9: How Similar Are The Microbiomes Of Identical Twins?

Episode 9: How Similar Are The Microbiomes Of Identical Twins?

Identical twins are an interesting case study because while they have 100% the same DNA, they often vary widely in everything from their hobbies to their health issues. That was certainly the case for Lisa and Alana Macfarlane, two identical twin DJs, better known as The Mac Twins.

Though they currently live in London, the twins originally grew up in Scotland eating foods that didn’t do a whole lot to help their gut health. Years later, as adults, they participated in a research study that analyzed the contents of their microbiomes. The surprising results catapulted them on a new quest to learn all about their own gut health, and eventually, to launch The Gut Stuff, a platform dedicated to breaking down the barriers between microbiome research and the public.  

People have devoured information from The Gut Stuff through online features like “Ask A Nutritionist” where visitors can ask any question for free, and in-person at their sold out supper clubs and events.

On today’s show, they talk about that initial discovery that shocked them to their core, and why they became so passionate about topics like poo. They also tell Andrea what they’ve learned after talking to thousands of people in the UK about gut health and dish on their plans to make 2019 their most inspiring year yet.

To check out The Gut Stuff, visit the website at or follow the twins @thegutstuff and @themactwins on all platforms.


On this show, you’ll learn:

  • Who are the Mac Twins? (1:15)
  • Before getting started, their knowledge on gut health (4:51)
  • How the UK has dealt with gut health information (5:48)
  • What was their diet and lifestyle like, previous to getting studied? (6:57)
  • How the experience led to a diet that they can both best follow (8:37)
  • The ways the diet changes led to improved health (10:47)
  • What their diet looked like as kids growing up in Scotland (12:53)
  • Biggest surprises/most interesting things that they have learned along the way (13:38)
  • The biggest gut health misconceptions that they encounter (15:30)
  • The Mac Twins plans for 2019 (16:46)
  • Are their DJ lives crossing paths with their gut health lives? (18:17)
  • What they are most excited about moving forward (19:34)

BIOHM gut quiz


Andrea Wien: I'm Andrea Wien and you are listening to the Microbiome Report powered by BIOHM Health. On today's episode, I'm talking to Lisa and Alana Macfarlane, two London-based DJs turned microbiome fanatics. The Mac Twins, as they're called, are the official DJs for the UK's Love Island. Think The Bachelor meets Real World meet Survivor. And the founders of the website, The Gut Stuff. The identical twins initially became interested in the microbiome after participating in a research study on twins, where they found that despite having 100% the same DNA, their guts were 60% different. Now they've made it their mission to teach the world about microbes.

Through The Gut Stuff, they launched a YouTube series featuring leading scientists, hosted a popup dinner series called Supper Club and added a section on their site where anyone can ask a nutritionist a question for free. On the show, we talk about how the news that their microbiomes were so different rocked their understanding of health and dig into the big plans they have to make gut health just as cool and accessible as nightlife. To start, because I don't think many of our listeners have heard of you guys or heard of your project, can you just tell me a little bit about yourselves?

Alana Macfarlane: Of course, yeah. So we're actually primarily DJs. So yeah, we've DJ-ed for like seven or eight years, and we just volunteered for twin research and here in London, we have one of the biggest twin research facilities in the world at Kings College Tommy's Hospital. And we just saved up just to find out what was different between us. And it's like getting a sort of free health check every six months. So we were like, "Yeah, we're in." About four to five years ago, Tim who heads up the facility was like, "I've got this new experiment. It's quite intrusive. Not when people want to do it, but do you want to be the first? The chief guinea pigs in it?" And we were like, "What do we have to do?" And they were like, "You've got to send your poo off in the post every day for two months and have four colonoscopies."

We were like, "Yeah, where do we sign? We're in." From that, we basically, it was what we didn't know at the time, we were one of the first people in unit to have our guts analyzed and sequenced. So we found out from our bodies that we obviously have 100% the same DNA, but only 30% the same microbiome. So they did that same test on more twins and found the same thing. And then over the past sort of three or four years, they've done different experiments on Lisa and I from measuring blood glucose levels with the microbiome, to doing different diets, doing exercise. And as we were going through all the research, we were just fascinated by the gut and how important it was and how it was linked to everything. And we then got quite angry as to why nobody knew about this. All the sort of different people that we were speaking to in lots of different departments from immunology to Parkinson's to mental health.

Well, none of them were speaking to each other. And actually we were like, "Why does nobody know this information?" And here in the UK, there was sort of like tabloid papers talking about it, but it was a bit like [inaudible 00:03:04] and not actually cement in the importance of the gut for overall health. So we set up a YouTube series about two years ago, which is mad, just interviewing scientists about gut health, but making it fun and accessible. So every time we were interviewing the scientists, we were like, pretend we're toddlers. So we sort of distilled hour long interviews down to like two minute bite size chunks for a younger millennial audience. And then the New York Times hailed the gut as the thing of 2017. And we had set up a website, just ethically we thought it would be good for somewhere for people to go.

It was so bad. The branding was awful. It was just like, we just put scientific papers up for people to sift through. And the website hits started through the roof. And we were like, right, okay. This is actually a thing. The more passionate we got, the more we were like the people that need this information aren't getting it and we need to... We were from working class Scotland and if a lot of these people knew just one nugget of information, for example, they should be eating more fiber, everyone wouldn't die very young as they do Scotland. And so there was a lot of passion in there to get the word out there. And it was just a passion point project at this point, because we were still DJing a lot. And then we teamed up with a branding agency called JKR, made our amazing brand and that put us on a platform. Yeah. And it's just sort of went from strength to strength from there. It's sort of a bigger beast than we ever could have imagined it.

Andrea Wien: Well, it looks great now. The branding is on point and the content is very helpful for people who are just getting started in the microbiome and trying to figure out what it's all about. But is it safe to say then before you had the testing done on yourself, you didn't really think much about gut health or didn't really have an interest in gut health?

Alana Macfarlane: Literally. Yeah. Zero. This was like very much all new to us as we started going through the experiment-

Lisa Macfarlane: What made it seem quite good for us, coming at it from an objective point of view, not having a background in nutrition because we can make it quite clear and accessible because if we can't understand it, a lot of people are going to be able to. And also you think laterally about things and ask different questions when you're not within that industry. And I think that having an unbiased voice, but also realistic voice in this space for the microbiome at the minute, is really important because a lot of the information is sensationalized and there's a hell of a lot cowboys out there. So I think for us, we sort of ask the obvious questions and we're able to sort of come at it from a sideline point of view, I guess.

Andrea Wien: What's been the reaction to the project overall? Are people excited about it? Are they blown away that this is information that they didn't know? Kind of what's been the response?

Alana Macfarlane: It's difficult. On socials, you get sort of one response, but we actually took over one of the main tube stations here for a week with six brands that we love in the space. And that was brilliant because there was yeah, 70,000 people a day came through and it was really good to see what the kind of baseline knowledge was and where could you... Again, I think London is probably similar in New York, it could turn into a bit of an echo chamber where you assume people know more than they do. And actually it's just a lot of people in the industry talking to each other. And actually what we refer to as the baseline knowledge is still quite new, and actually probiotics, people are still not even grasping how important the gut is, nevermind probiotics. And polybiotics and prebiotics and all the rest of it. So I think that people are really shocked and surprised about how much impact it has, but also I think none of us can overestimate how much people actually know in the space.

Andrea Wien: From your own journey, so when you go back to when you had your microbiome sequenced for the first time and only 30% of it was the same, what kind of diet and lifestyle were you living? Were you living pretty much the same? Traveling together and eating a lot of the same foods or was it completely different?

Alana Macfarlane: Yes. I mean, we live quite similar lifestyles. I think we were even living together at that point, where we?

Lisa Macfarlane: Yeah.

Alana Macfarlane: Maybe just. They've obviously found out through our bodies that it can be from things that happened so many years ago. I suffered from arthritis since I was seven and it was a hereditary type of arthritis. So the doctors were just baffled why Lisa didn't have it as well. So it all started to make sense of things had happened in the past. We didn't have exactly the same illnesses or antibiotics growing up. We actually lived apart for five years. So I stayed in Edinburgh for university and Lisa came down to London. So there were so many different factors that could have contributed to it. But the first experiment we did, they put us on the same diet for two months. So they take that variable out. So yeah, even with the same diet, we were still completely different, which was fascinating.

Andrea Wien: Did they get closer together? Was it like, okay now 60% is the same or was it still always really far apart no matter what you did that was the same?

Alana Macfarlane: The diversity was, it got a lot because we did one month of eating just processed foods and drink and alcohol. And then we did a month of eating fiber bars and just having like a veg plant based diet. And in both our diversity increased by a lot in that month which was interesting, but it was still pretty different. So the species were different. But I think it'd be fascinating though, to do it again when the technology is further forward, which we're planning to do next year.

Andrea Wien: So doing all those experiments and getting the gut sequenced at different times, have you found the diet that's right or best for you or makes you feel the best with the least amount of symptoms?

Alana Macfarlane: Yeah. Yeah. I mean, we've been quite lucky. Both of us don't really suffer from digestive issues on a constant basis. It's more after we've been on an night out or whatever, like everyone. But yeah, we've definitely found what works for each other. And for example, I really like fasting and Lisa gets very hangry, so there's just a quite a lot of different things. But the things that we both do now, we both think about fiber a lot more. We have fermented foods, whereas before we'd never even heard of fermented foods. I mean, coming from Scotland, even avocado was quite a stretch or kale, we were like, "Oh, that's something we fed the guinea pig when we were seven for its birthday." So yeah, just in terms of variety and diversity, we sort of adopted that. And even our first taste of kombucha, we were like, yuck. But now, we've just changed our pallets and it's something that's in our daily lives now. They're all fermented foods.

Andrea Wien: When you first got that result back and it was the 30% were only the same, what was the breakdown? Do you remember the breakdown of more pathogenic strains versus beneficial when you just weren't even paying attention to gut health?

Lisa Macfarlane: Well, Alana actually had a lot of them, so I've always been a stone heavier. And even when they put us on the same diet, they weren't quite sure why. Alana had a lot of christensenella and I had-

Alana Macfarlane: Lucky me.

Lisa Macfarlane:...virtually none. So there was that. And then the thing that surprised us most, I think was just that my diversity was pretty shocking because I had been on a series of antibiotics for quite a long time and Alana's was a lot better. And she was genuinely healthier. This came out of the studies, but obviously we're still so far early doors into knowing what each bacteria do specifically. But yeah, Alana was always much healthier than I was, thinner, which obviously we don't focus on the weight thing, but if people do, then that was what happened and just generally better. Whereas I have got quite a bad immune system. I get ill quite a lot. And yeah, I was just interested in that now that there's potential answer to that.

Andrea Wien: Did you find then, with yourselves that a higher fiber plant based diet that led to more diversity also made you feel better?

Lisa Macfarlane: Yeah, I think in terms of, yes, I think it definitely did make a difference, but also, in being experimental with food kind of makes you happier because you're making better choices. But it's also quite exciting to learn different vegetables. I think that here in the UK, we have loads of different plant-based veg available to us and we eat on average six. So it was quite good to just kind of try and tick off 40 different foods. And we're starting to receive lots of different niches as well as obviously the different types of fiber that we're feeding the bacteria.

Alana Macfarlane: I think as well, over the years, in our 20s, before we knew anything about gut health, I think I speak for a lot of the UK nation-ers that all the diets that everyone went on were about restriction. And that obviously mentally, plays a shocking part in your health. But also it was just always something negative. It was always like a chore, a task. But with gut health, it was all about adding things and trying things that you haven't tried before. And I think that's super important as a lifestyle change. But here at The Gut Stuff, we're not angelic. It's not like we completely have switched our lives. It's about small, easy, tangible swaps, rather than a big lifestyle overhaul. I mean, we still like to have a vodka on a Saturday night. But I think that's why The Gut Stuff has resonated with so many people because we aren't telling people to change themselves. It's just about tweaking things to make themselves feel better and realizing that there's this big whole ecosystem inside you that can help you do that.

Andrea Wien: Yeah. It's not about living in a wellness bubble and never letting anything that could be potentially harmful in, it's about balancing so that your system is more able to handle those things when you do have the vodka on Saturday night, or maybe a cupcake over your birthday.

Alana Macfarlane: As we go into Christmas, prevalent in those discussions.

Andrea Wien: In terms of your diet as kids, what did that look like? You've kind of alluded to it not being very diverse and not being very plant-based, but what was that like?

Alana Macfarlane: I mean, working class [inaudible 00:12:54], it was like crispy process pancakes, everyday for lunch we'd have for break time, we'd have a Gregg sausage roll. For lunch, we would have a chip roll and then a softie, like a sandwich. And then sweets. I mean, it was bad.

Andrea Wien: Yeah. It sounds like it. It sounds like it definitely was beneficial to go through this study and kind of move away from some of the habits that you'd formed as kids.

Alana Macfarlane: I mean, we used to have deep fried pizza. That is-

Andrea Wien: Oh geez. Sounds delicious, but probably not the best.

Lisa Macfarlane: Pretty much as bad as you can get.

Alana Macfarlane: Yeah.

Andrea Wien: So through this process of really learning about your own health and then now spreading the word to other people, what are some of the most surprising or interesting things you guys have learned along the way?

Alana Macfarlane: A lot of the things are sort of like little facts. But when we spoke to, so we spoke to for the YouTube series like six of the top scientists in the world. And then so six episodes turned into 36 episodes. And even then, I watched some of the videos back and I'm like, "Oh my God, I forgot about that." That like 95% of your serotonin is produced in your gut. The majority of your immune system is housed in your gut. Just like little facts like that. You're like, wow, this thing is super important.

And yeah, I think the science is something that has always pulled us over and that sense and how it's been ignored for so long. I would say Hippocrates said, "All disease begins in the gut." Hundreds and hundreds of years ago. And then we all sort of chose to ignore it. And I think that just generally it surprises me how lax people are about what they put inside their bodies and how badly they may mistreat the interior. I'd say that that's the sort of thing that continues to surprise us and how amazing science is and how thorough it is. And yeah, just the future really, really exciting.

Andrea Wien: I think it's interesting too, that I think a lot of humankind knew these things inherently in some way back centuries ago and then in our quest for medicine and modern day medicine, which of course is amazing and has its place, we've lost a lot of that inherent knowledge. And yes, maybe our ancestors didn't know why they felt better when they ate more diverse foods or ate fermented foods. They just did it because it kept them safer from illness. And now we're really getting that science to back it up, which is so exciting.

Lisa Macfarlane: Exactly. I think it's like the why piece that we've all been waiting on. Even with fiber, and just I think that we've been, the technology has meant that we haven't got there yet, but now it's all starting to unfold and it's all kind of starting to come together.

Andrea Wien: So in that same vein, talking to people that maybe don't know as much about gut health as you do now, what are you finding are the biggest misconceptions? What are people most confused by?

Alana Macfarlane: The complex nature of it? People are like, "What do you mean my beer belly?" Or, "Do you mean [inaudible 00:15:35]?" And it's like, "Yeah, sort of." It's just very difficult for people to get their head around that bacteria can be good. It also is a difficult message for the personalization element of that. It's easier for us to portray because obviously we embody that. If we can't be sold the same thing, then the nobody can. But there's a lot of bad errors that come up. And even just the words microbiome, if you come out with London, even an hour of London, you say the word microbiome or probiotics, people are like, "What are you talking about?"

So the words that people are using are complicated and scientific. It's probably the word that I think that is confusing people the most. And just getting your head around that you're outnumbered by the ecosystem that lives in and around you. I think just people are just like, "Oh God, no, it's freaking me out." But it's about giving people bite size chunks and making it in steps. If you overload people with information, they just run away. And I think that's what we've tried to do is give people small bites of information and if they want to delve deeper into it, then they can, and the science is all there. But I think it's about small, simple nuggets of wisdom.

Andrea Wien: Yeah. What's your overall goal with The Gut Stuff? Where are you guys going in the next year?

Alana Macfarlane: So we're just about to move into product. And then we just signed the book deal for a digestive work book. We're taking the road show that we do around the UK. And I think maybe to New York to sort of spread the good gut word. It's about reaching people that wouldn't necessarily come across as organically or online and we're lucky that our social following is growing rapidly, but it's about trying to hit people that wouldn't necessarily come across us in that sense or aren't in the health and wellbeing space. So that's the main aim of The Gut Stuff is to empower everyone with gut health. And we're going to do that through online and content and media, but through products and services as well. So it's a big job and it keeps us up at night thinking about doing it.

But I mean, it was by chance that we came across it, but we're super passionate about it. And I think it's the time. And I think a lot of people and initially when gut health started to come to the forefront of the media was seen as a bit of a fad, but it's trying to get the message across that this is going to be the future. And the future of healthcare is a big beast and it takes a long time for it to catch up with the science. So that's something that we'll probably come across in this country as well. And then [inaudible 00:18:02] is stretched enough as it is, and to bring new works and new practices in, it's going to be difficult and it's going to take a long time, but I think it will get there.

Andrea Wien: Are you incorporating your DJ lives into the world of gut health now too? Or is that maybe going to become more of a past life?

Alana Macfarlane: Yeah, yeah.

Lisa Macfarlane: At the minute we can sort of do both because we DJ in the evenings, but yeah, I'm not sure how long we can keep. It's quite good that we do a show here in the UK called Love Island. And I don't know if you guys, I think you can maybe stream it in the US, I'm not sure. But yeah. And that's sort of like one of the biggest telly shows here and we're the DJ of that, but if we can get that young Love Island audience talking about gut health, then-

Alana Macfarlane: We've done our job. Or thinking about the body from the inside out rather than the outside in. So we're going to DJ good into next year. We're going to keep doing it, doing the big ones, but I think we'll start paying it back.

Andrea Wien: I'm picturing like a whole festival all around gut health and music. That's like the ultimate millennial festival, right? All about wellness and gut health and then having some awesome music on the side.

Alana Macfarlane: Yeah. I think it's true. That kind of hedonistic lifestyle has to be balanced out with something. Yeah, because at first, we were like, "Oh my goodness, what's everyone going to think? Two DJs talking about poo?" But actually it works because we're reaching the audience that we play to do our sets is exactly the sort of audience that needs to know about this stuff. So yeah. And they do sort of surprisingly go hand in hand.

Andrea Wien: When you think about what you're most excited about in the world of gut health and where the science is going, what do you ultimately think of right away?

Alana Macfarlane: The gut brain access, I think is something that is really exciting. I just think that generally thinking about having a more holistic approach to health care is something that we need to start marrying health and wellbeing together. And I think that people becoming more aware of their bodies and that everything's linked. Obviously at the minute there's a bit of sensationalizing around that and obviously mental health multifactorial. So there's a lot of people making sort of sweeping statements that don't make sense. And a lot of the studies that have been done have been done on mice, but is a super [inaudible 00:20:07] of research and really exciting for us as a company because I think we can really make change with it. I think for me as well, it's about this idea of prevention. So people don't actually check in with themselves until they're not well, and we base the word health on just not being unwell. And I think that shouldn't be about that. Sort of educating this next generation for prevention of disease and illnesses is super exciting.

Andrea Wien: So when someone comes to you, maybe they've seen the website or maybe they come across you at an event now, or even at a DJ set and they have no idea about gut health, what are some of the simplest things that you tell them just to get started in terms tuning into their body and how to start optimizing what's going on inside?

Alana Macfarlane: Yeah so food diary is the big thing. I think we don't check in with our bodies unless, like I was saying, we're ill or we're hung over. And I think doing a food diary is key. And I think when you go to your doctor, it's the first thing they'll ask you to do if you go to them with an adjacent issue. So food diary. Upping your fiber intake and variety and trying fermented foods. In the UK, it's not actually fermented foods isn't mainstream yet so you can't just go to a supermarket and buy lots of kombucha, unfortunately, but we're getting there.

Andrea Wien: Well ladies, thank you so much, Lisa and Alana. It's been great to have you on. If people want to check out The Gut Stuff, check out your music, hear more about what you have going on, where can they find you?

Alana Macfarlane: On Instagram it's just @thegutstuff and then our DJ handle is @themactwins. And then just the website, you'll see everything there.

Andrea Wien: Perfect. Well, thank you so much. Excited to see how it grows and hopefully when you come state side, we can meet up.

Alana Macfarlane: Yes, definitely for sure. Have a kombucha.

Andrea Wien: Perfect. Have a great day. Thanks so much. I'm Andrea Wien and thanks so much for listening. Head to the show notes on our website to connect with the twins. Next week, we're going Zen about the power of meditation on microbiome. In the meantime, don't forget, you can save 10% off any product at by using the code BIOHM10 at checkout. We'll see you next week.


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