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cover of episode Snippet 21: Why Your Gut Is Your Second Brain - Expert Dietitian Sophie Medlin

Snippet 21: Why Your Gut Is Your Second Brain - Expert Dietitian Sophie Medlin

2023/4/18
logo of podcast Deep Dive with Ali Abdaal

Deep Dive with Ali Abdaal

Shownotes Transcript

Oh, by the way, before we get into this episode, I would love to tell you a little bit about Life Notes. Now, Life Notes is a weekly-ish email that I send completely for free to my subscribers, and it contains my notes from life. So notes from books that I've read, podcasts I'm listening to, conversations I'm having, and experiences I'm having in work and in life. And around once a week, I write these up and share them in an email with my subscribers. So if you would like to get an email from me that contains the stuff that I'm learning, almost in real time as I'm learning it, you might like to subscribe. There is a link down in the show notes or in the video description.

So because your gut is constantly communicating with your brain, again, if your gut is not happy, things are communicating differently. But also you could just not be producing enough serotonin for various different reasons, or your gut might not be sending the right signals up to your brain. So you might have, if we looked at your microbiome, and it's certainly not necessary to do that, we can do this in clinic without testing. But if we looked at your microbiome, we might find that you've just not got enough of these bacteria that are doing this particular important job with brain connection stuff.

So what we would suggest then is to really optimize the gut. And you know, what happens, Ali, as you know, is when people are busy and they're working too hard and they're doing a side hustle and everything else is high pressure or they've got a family and everything else, people tend to make their diet quite small, not necessarily in terms of volume, but the types of foods that they're eating. So they might end up eating the same types of foods on repeat.

What I see is people, there's kind of two camps here, the people who do like the meal prep stuff and they eat the same foods five days a week and they think they're being super healthy, eating sweet potato and broccoli every day. Or you have the people who are just living meal to meal prep, you know, it's wherever they're going every day, the same sorts of things, but just various different places and nothing's particularly planned or thought through. And inevitably, both of those ways of eating have an impact on your gut health, whether you feel it in your gut or not.

So that way of eating limits the types of fibres that your gut bacteria are being fed and the most important thing for your gut health is that you're eating 30 different plants a week, so trying to eat loads of variety of different types of plants. That includes fruit and veg but also nuts and whole grains, different types of grains. We're super fixated in this country on like oats and wheat but actually there's so many different types of grains that our gut really benefits from.

So, when you're busy and you're struggling and you're eating meal to meal or you're eating the same foods on repeat, what happens is your gut health, your gut sort of function might not change, but your gut health is inevitably not optimised. And that's when you can have these problems with lack of concentration, focus, energy, getting bugs all the time, that kind of stuff.

And really interestingly, your gut bacteria communicate with your hypothalamus, so that bit of your brain that controls things like cortisol production. So really early in your life, your gut bacteria dictate where your sort of HPA axis is set, so how much cortisol you release under given circumstances. And we all need some cortisol, right?

but we don't want loads and loads of cortisol because we've got loads of anxiety and stress all the time. We can really struggle to concentrate and to focus. So we can use our gut bacteria to try and reduce that and make things a little bit better in that department. We can use them and harness their powers to get more serotonin, which helps us with better sleep and concentration and focus and all those important things, those happy hormones.

And we can also just try and calm down those messages from our gut to our brain, which are distracting our brain all the time. And your gut bacteria are going to be saying, we need more plants. And you're going to be not reading that properly and giving them more sushi. And that's not quite what they want. Wow. So it sounds like you're saying, and please correct me if this is an oversimplification, that changing up what you eat can have a massive impact on your

focus productivity performance happiness absolutely because all of those things are linked gut brain everything yeah fundamentally i mean and proven in amazing research and science yeah

What kind of research has been done on this? I guess I'm thinking healthy people rather than people with official gut problems. Yeah, so the amazing work of John Kryan is a really good place to start looking at this stuff if people are interested. And he's written an amazing book called The Psychobiotic Revolution. So psychobiotics are these gut bacteria that communicate with our brain. So they're the ones that we're particularly interested in when we develop the high smart probiotic, for example. So work that's been done in that area to start within rodent models is

they used a model of an autistic mouse and a model of a non-autistic mouse, so a sociable mouse, and they took the microbiome. So they took a sample and gave the microbiome of the autistic mouse to the sociable mouse. And the sociable mouse starts to show autistic traits. And when they swap them over, the autistic mouse starts to become a sociable mouse just because its gut microbiome has changed.

So that was the early work that they did trying to understand how much our gut microbiome is impacting our mental health, our mental performance, how our brain is working. So similar studies to that have then been replicated in humans, in other places. And to be clear, that autistic spectrum disorder stuff in humans is so complex and we can't replicate that exactly in humans as yet. But there's certainly something going on there, which is what we generally learn from rodent studies.

We've also got some great data showing things like increase in production of serotonin when we use particular probiotic species. There's great data showing that using particular probiotic species within treatment diets and things like that, so within treatment within studies, in controlled studies,

improves anxiety, depression, all of these kinds of symptoms. And wider nutrients within this world, if we think about things like omega-3s and B vitamins, they've been used in place of anxiety and depression medications, SSRIs, that kind of stuff. And they work as effectively in some people some of the time in studies. So we can use all of these things. And a similar work has been done with the two strains we use in the smart probiotic in

in terms of seeing whether they work as effectively as common anti-depression, anti-anxiety medications. And they do. So much so that there's health claims on them in Canada that people can say these are definitely shown to improve anxiety and depression. So there's great data. It's a young field of research, but it's super exciting. And it's very solid research just showing the magic that we can harness from our gut.