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EPISODE 3: Should we trust our gut?

TAI: There's a saying I always hear whenever I'm stuck making a decision. I remember this one time I was at the farmers market and I had two dollars in my hand and I’m like do I want to buy the maple candy or the cookie? Do I want the sweet sugary maple candy ro do I want the soft doughy cookie. Maple candy? Cookie? It was just so hard to choose. My friend came over and was like Tai why are you standing in the middle of the farmer's market? And I was like I can't, I can’t decide. And then he'd look at me and he’d say dude just trust your gut. Should I trust my gut?

[THEME]

I'm Tai and this is my podcast, Tai asks why. There are so many good questions that you just, you want to get answered: How do we fix climate change? What happens after we die? What is love? Why do we dream? And should you trust your gut?

[THEME OUT]

TAI: My gut is this big pile of intestines that digests my food. I don't really know what’s to be trusted there. I know that I get these feelings in my gut like butterflies when I'm nervous or when I'm hungry like my stomach will like cramp and feel like squeezy.

But like why? Is my gut able to make decisions and like tell me what to do? That seems pretty crazy because that means it has a brain and that seems crazy. You know it's just like my intestines, but like maybe there is a brain in my gut, but at the same time it's kind of far fetched and wacky. So I decided to take this theory to the park and see what my friends had to say.

TAI: Do you think there’s a brain in your stomach?

VOICE 1: No. No.

TAI: Why?

VOICE 1: Because your brain’s in your head.

VOICE 2: I think your brain makes everything you feel possible

VOICE 3: There couldn’t be a brain because there wouldn’t be space or else you'd have like a big lump on either side.

VOICE 4: My feelings and anxieties and stresses they come from here. My gut.

VOICE 5: Your stomach does not think, except when it's hungry.

VOICE 6: I think there is some sort of connection.

KIA: But I imagine myself as creatures that are like waa, waa, waa. It’s really, really complicated.

TAI: You know I think Kaya is on to something. It is like really complicated and I did a little bit of research and apparently there are little creatures in our guts and they're called microbes. I remember reading this one factoid from the Science Center saying that all the microbes in your body weigh about a kilogram and you know that's crazy. These microbes they're apparently all over our body and they're like inside us everywhere, therefore if we're supposed to trust our guts then does that mean that we have to trust all of the little microbes? Do the microbes have a brain? Are they sentient? And as I was doing this research, I saw this scientist called Dr. Embriette Hyde

EMBRIETTE: For my Ph.D, I studied the microbiomes.

TAI: So I decided to call her up. What is a microbiome?

EMBRIETTE: So you can’t see it because well for one, it's inside of you, but for two, they're invisible to the naked eye. So it’s all of the microbes that live in and on your body. So that includes bacteria, viruses, fungi, some parasites and it's not just the microbes, but it's the things that they do in your body.

TAI: So the microbiomes in our gut is responsible for a lot of processes in our body. But like I wanted to know do the collection of microbes form like a brain?

EMBRIETTE: Your gut is full of neurons, which are the same exact cells that are in your brain. And there's this amazing nerve called the vaguest nerve, which connects your brain to your digestive tract and your brain can send signals directly to your gut and your gut can send signals directly back to your brain through this nerve and they're always communicating and talking to each other. And because of that a lot of people like to call this system the second brain in your gut, but I think it's probably more appropriate just to call it an extension of your nervous system.

TAI: Does our brain have like a conscience and think sentiently?

EMBRIETTE: We don't fully know the answer to that yet. Microbes live in your gut and they help affect this communication between your gut and your brain and people are wondering if maybe microbes have a mind of their own and if they do then maybe you know you could extrapolate a little bit and say well if the microbes have a mind of their own and they're affecting how my gut is talking to the brain then maybe that could be the conscious aspect of it, but we just don't know yet.

TAI: What do you think the brain and the gut are communicating? Is the gut being like we’re able to process that pizza that you sent down a couple hours ago. Now bring on some more and then it sends it to your brain and then your brain tells you, hey, I'm hungry. Give me food. Is that what it's like?

EMBRIETTE: Well that's definitely part of it, but I think it's just a little part of it. So have you ever I don't know you seem like a very good podcaster or interviewer, but maybe if you've ever gotten nervous before giving an interview or having to talk to somebody and maybe you felt butterflies in your stomach, that is a result of your brain and your gut talking to each other. In addition to giving signals about whether or not we should eat or whether we're hungry, there's a lot of emotional input as well that comes between your brain and your gut. If you are stressed out or you're really sad about something, you'll notice that you're not quite as hungry. It's really amazing the ways that your brain and your gut can talk to each other.

TAI: Yeah because like you know if you're sad then the gut is like oh man my partner’s bummed out. Now I'm bummed out.

TAI: I remember seeing my best friend at Spirit of Math and he looked bummed out. So I’m like oh dude what happened? And and then he said aw my hamster died. And then he was just gloomy the whole time and that just made me gloomy and I was like oh no, cause when he’s sad, I’m sad.

TAI: So if my gut brain and my head brain are like close friends, do I make my head brain sad when I eat something you know kind of nasty?

EMBRIETTE: Let me ask you a question. Have you ever eaten a food that you used to like and now you don't want to eat it at all ever again? Just thinking about it makes you feel sick?

TAI: No.

EMBRIETTE: Well that's happened to me and that's happened to one of my best friends. She hates macaroni and cheese, which I think is crazy, but she just doesn't like it anymore because one time she ate it and it made her sick. And this has to do with a really intricate and elegant way that your memories are formed and how they make you react to certain situations and the gut brain access has a very important role in that.

TAI: So our eyes and our senses are tied to our head brain and those will help make us recognize the mac and cheese.

EMBRIETTE: That’s right.

TAI: Right? So the gut brain needs to communicate with the head brain because the head brain can recognize it.

EMBRIETTE: Yeah absolutely. And the next time the food goes in, your brain will say last time my immune system, you know told me this, so maybe I just have bad memories associated with this and then it completely affects whether you want to eat that food or not.

TAI: You know when like you're like oh do I want to buy the candy bar or save the money? You're stuck with the indecision and then like if you're with like your parent or a friend they'll just be like hey do you trust your gut? Do you think that's like scientifically accurate and do you think a scientist was actually like I am a smart scientist, your gut has a brain. Trust your gut because it has brain.

EMBRIETTE: You know a lot of it has to do with this memory formation. Sometimes we don't remember the memory, but our brain subconsciously remembers it and our gut also remembers it and so together they are able to tell us that, hey trust us on this point and you know make this decision versus that decision.

TAI: When you say trust your gut, do you think that’s the brain thinking and then the message gets sent to the gut or do you just think it's the gut itself?

EMBRIETTE: Your gut doesn't come up with it on its own. Your brain sends a message to your gut. You're just not aware of it and then your gut then responds and sends a message back to your brain and you're aware of that one and then you get that feeling from it and you make your decision whatever it is that you decide. And you know sometimes people fight against their gut feeling and they go with just their head brain. Half the time it works and half the time it doesn't.

TAI: Does that mean do you think you should trust the gut itself or the brain?

EMBRIETTE: If you take one away, you break that whole cycle of communication and then the messages you get are going to be different. They're not going to be full. You’re going to be missing part of the story and so I really think it's both. You have to trust both.

TAI: And then if your gut brain is gone then your head brain is sad because he doesn't have a friend.

EMBRIETTE: Yeah. Exactly.

TAI: Maybe the gut brain is the head brain's only friend and only possible friend.

EMBRIETTE: That's a very interesting way of putting it. I like it.

TAI: They've been with each other through so many hardships.

EMBRIETTE: They have.

TAI: Grumble, grumble, thank you.

TAI: So there is a brain in our gut that's made of all these microscopic organisms and they're constantly communicating with our head brain and they can even infect our emotions. And so when we say trust the gut, we're kind of just saying trust the head brain-gut brain friendship. But like should we trust that friendship because these microbes, they’re still not like us. They're external organisms. So do these microbes define our selves? And if so, what really does that make us? Now these are the kind of questions that Dr. Tobias Rees is asking.

TOBIAS: About a year ago I became director at a research institute in downtown Los Angeles called Berggruen Institute, where I'm building a new program and I also became Reid Hoffman professor of humanities at the New School of Social Research in New York.

TAI: I'm just a kid who was playing in a sandpit, you know.

TOBIAS: I'm just a kid, who’s a little older. People sometimes refer to this as the second brain. That's actually wrong because when you think in terms of evolution, which nervous system our brain or nervous system in our gut came first then it's actually in our gut. So this is not the second brain, it’s the first brain.

TAI: So the gut brain, the brain in our gut, it came first, right?

TOBIAS: Yes, the gut brain came first. That's right.

TAI: Then why has barely anybody even heard of it?

TOBIAS: So when we think about intelligence, everyone usually touches their head and thinks it's in their head, but they don't recognize in that moment that it actually happens in the whole body and they absolutely don't think about the possibility that microbes, bacteria are a part of this. Now maybe eight years ago when the first studies were published that suggested that there is a direct communication between bacteria in our gut and our brain in the skull, you can imagine many neuroscientists thought that's crazy. Why would that be because they have been studying the brain as being tucked away in our skull and not really related much to the body. And so the idea that the bacteria are important is wild.

TAI: And this is where it gets really, really weird. Tobias thinks that these bacteria change everything about who we think we are.

TOBIAS: If you think about your brain as being you, as being the place where your consciousness or your sense of self or your mind is located, but then your brain depends on little substances that are produced by something that seems to not be you, that seems to be external to your body namely bacteria, then you have a very funny quirky situation where not you is actually part of you. We don't know where Tai ends and his microbiomes begins. So I'm not really just Tai the person, I'm Tai the ecosystem and there's like a weird flurry of microbes in me and around me and the world I interact with becomes part of me and my mind.

TAI: Like at that point, what makes me a human boy? When I, when I ate that cookie and that cookie became part of my brain, is that a good thing? Should I have stuck with the maple candy? Did I really make that decision or did the cookie microbes just want to be with more of their family? And if I'm not the one making the decisions, who am I?

TOBIAS: For such a long time, the brain was the place of self. But if the brain, how it functions, depends on chemical substances that are produced by bacteria, how can one think about humans as more than mere human? And this more makes it very difficult to think about the human as such as if we would exist as free or set apart or as independent. We’re like thoroughly integrated with our bacteria and through them with our environment.

TAI: Do you think the listeners after they turn the podcast off, do you think that all this talk is going to change the way that they think about themselves and define themselves?

TOBAIS: The very short and very straightforward answer is Tai,I so hope so. When you take the microbiomes serious and you say well I don't know where Tai ends and his microbiome begins and what he thinks or what he will do depends largely on his bacteria, then you cannot make this differentiations between the human on the one hand, creative, meaningful, philosophical and mere nature on the outer side. So you have to learn to think about humans as integrated. In a moment there we have a lot of mass species extinction, where we have climate change produced by humans. So it will be very interesting for me and very important for us and the planet if we could succeed in thinking about ourselves as integrated.

TAI: Thank you so much for spending the time to talk to me just a guy with his hands in the dirt wanting to know more.

TOBIAS: Thank you Tai. This was a lot of fun.

TAI: So I started this whole journey trying to find out if I should trust my brain or my gut

and I was kind of like pinning them against each other, pent the non-style. But now I know that my gut and my brain they can't be separated and we actually can't really separate our minds from our bodies and our bodies from the world. It's a lot to take in, but like I wonder if Tobias is right. I'm thinking like if we can make people aware of what we really are, could we get them on board with the like superhuman perfect the Earth, perfect us program? And I wanted to start with my brother because you know he's my brother. He lives right beside me.

TAI: Hey Kien.

KIEN: Hey Tai.

TAI: How are you doing?

KIEN: I'm good. I played soccer games and had lunch and snacks. What I normally.

TAI: Anyway, when you think of yourself, you think of your brain in a way, right?

KIEN: When I think of me I think of like my body and my head and my parts.

TAI: Yeah, but like have you ever thought of your gut as a part of your identity brand? Your brand identity?

KIEN: No, no.

TAI: So Kien, how shocked would you be if I told you that the bacteria that help form the gut brain are external bacteria. That hot dog you ate Kien.

KIEN: How do you know I had a hot dog?

TAI: What, you did?

KIEN: Yeah.

TAI: Oh my God, that’s so magical. But what do you feel about that?

KIEN: Cool.

TAI: Would you consider that gut brain is a part of you, if it's just like external organisms?

KIEN: Yes because it is part of me.

TAI: But the thing is they're all just organisms and microbes that aren't from you. Your intestines are just this basically this super duper long shaft that’s like and it goes all the way to your mouth, right? But we learned that the gut, which is part of it, is actually filled with external organisms. Do you think that kind of connects you with nature and the world in some way?

KIEN: Um, no.

TAI: Do you think this talk will change who you think you are?

KIEN: No. I already thought I was part of like stuff nature like nature stuff. Nature stuff stuff nature stuff.

TAI: This is getting deeper.

KIEN: It’s going to go deep into myself.

TAI: By the look in your eyes, I see that it already has.

TAI: I started with this question about the validity of the statement, should you trust your gut and that somehow through like a couple interviews it turned into enlightening people to the ways of the superhuman. Man. So now whenever someone asks me to trust my gut, I'm not going to think gut or brain, gut or brain. I’ll think, oh wait, they're best friends.

The head brain trusts whatever the gut brain says. So the next time I'm like do I want that poutine or do I want the burger or do I want the pizza, I’ll just listen to my gut, even if it's just more greedy pizza microbes because the gut brain is my head brain’s best friend.

[TAI SINGS GUTBRAIN SONG]

TAI: To whom it may concern.

I’m writing this from the top of Tai’s body’s shoulder, just between the ears.

It’s me, head brain.

I want to let the world know that there’s someone special to me.

Someone so special that I just wanted to tell you all.

His name is [sound]

But because you other head brains don’t understand that, you can just call him gut brain.

Microbes come and microbes go

But a gut brain will always be my bro (be my bro)

Best friends forever more

He’s my best friend

We always have the same sense of humour

We like the same food

I just eat whatever he’s craving

You know he always just gets what I want

He pretty much reads my mind

He completes me

Microbes come and microbes go

But a gut brain will always be my bro (be my bro)

Best friends forever more

He’s my best friend

That’s us for sure

Take it away gut brain

[Gut brain sounds]

Thank you so much for listening. I'm Tai Poole. This show was produced by Veronica Simmonds and Yasmine Mathurin. Our digital producer is Olivia Pasquarelli. Today my guests were Dr. Embriette Hyde and Dr. Tobias Rees. Thanks to Crystal Duhaime for the editorial assistance. The theme music is by the legendary Johnny Spence and also thanks Johnny for helping me write record the Gutbrain song.

KIEN: Next time on Tai Asks Why: death.

CLIP: The language of love is universal and so is the language of pain and suffering and loss.

TAI: Till next time. I’m Tai. Keep asking why.

TRANSCRIPT: Tai Asks Why - Season 1, EP 3

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