The Strange Location of Your Second Brain


If you’ve ever had a “gut reaction” to
something, gone with a “gut feeling” or had a “gut-wrenching” experience; you
probably didn’t realise we use these terms for a reason. In our gut lies our enteric nervous system
and it’s often called our second brain. We have the same number of neurons lining
our long tube of gut as we do in our spinal cord. And our gut is capable of reacting–like
causing cravings for a taco–without even communicating with our first brain. We have a community of bacteria living in
our gut called our microbiome. It’s influenced by what you eat, your genes, age, stress levels
an even where you live. Certain bacteria thrive depending on what you eat, and we’re starting
to realise what it can do. Our microbiome can communicate with our Central Nervous System
and influence our behaviour. In one study, germ-free mice (who aren’t exposed
to any bacteria since birth and don’t develop a microbiome), were compared to their germ-carrying
counterparts in a maze test. The germ-free mice showed a reduction in anxiety-like
behaviors in response to the maze. They were then housed with the other mice, and exposed
to their germs. But when they did the maze test again, they still showed a reduction
in anxious behaviour. The researchers suggested gut-brain interactions are important to the
development of stress systems, and the germ-free mice missed their window to develop one. A recent study found that prebiotics, little
fibre compounds that stimulate the growth of gut bacteria, have an anti-anxiety effect
in people. Participants were split into two groups, one that took prebiotics every day,
and one that took a placebo. After three weeks, those who took prebiotics had lower levels
of the stress hormone cortisol and in tests they paid less attention to negative information
and more attention to positive information. And other studies have shown that giving people
fermented milk products containing probiotics, or healthy bacteria, twice a day for four
weeks, altered brain activity in regions linked to emotion. The function of our gastro-intestinal tract
goes far beyond just processing what we eat. Of course our second brain, our enteric nervous
system, isn’t capable of conscious thought. But our microbiome can influence our behavior,
our stress levels and even our mood. So the next time you have that feeling of butterflies
in your stomach, remember there’s a whole lot more happening down there than you may
realise. For more awesome facts about yourself, head
over to my friends Alltime Numbers, where they’ll take you through the human body
in numbers. And if you don’t already subscribe to BrainCraft!
For a new, brainy video every Thursday.

69 thoughts on “The Strange Location of Your Second Brain

  1. The ancient Greeks believed that our thoughts come from our guts.  Where the phrase comes from 'gut feeling' has it's roots there.

  2. Does this mean emotional people have lots of bacteria in them? Like, with their blood type. Maybe this would explain the moodiness of pregnant women also, because tests have shown their blood type can change after giving birth.

  3. Hmm so our enteric nervous system helps in formulating intuition, and our gut flora helps in managing stress. So I guess the next time I'm preparing for an exam, I shouldn't just devote my time reviewing and reading everything, but rather I should also give more attention to eating right.

    Hence the start of The Pursuit of Gut Adeptness….  ^_^

  4. This is fascinating, but I worry about what it means for folks like me who have lost intestines to disease. Is our second brain now impaired?

  5. I love my microbiome.

    After twenty years working in the maintenance sphere, going into people's homes every day… working in messy corners under the sinks, etc… in many cases the dwellings of recent immigrants, or refugees… or later in the hospital rooms of people with goodness knows what germs…

    …I feel I must've developed by now, one of the most diverse microbiomes imaginable. And I credit it with keeping me much healthier than my peers.  

  6. Lmao. "There's a lot more happening down there than you realize" ;D


    I'm too primitive to be on this part of youtube … :/

  7. I somehow managed to read the title as "How to change the location of the your second brain."

    I DON'T EVEN

  8. Interestingly the enteric or gut brain is the 1st neural network, intelligence or brain laid down in the womb. The cardiac or heart brain is laid down next and then finally the 3rd brain – the cephalic brain is laid down last. While the cephalic brain is by far the most complex – it is not the most important as each has their own unique role. In essence, we need all 3 brains and each needs to be doing its own job.

    3 brains are better than 2 which is better than 1!

    There is a new and fast growing field of exploration called mBraining or mBIT which combines insights from neuroscience, neurocardiology and gastroenterology – in short head, heart and gut brains. Fascinating to say the least.

  9. Thank you! You just landed another subscriber. I want to be a research Dietitian on this topic. We are just scratching the surface!

  10. what her name? she is trying IRISH accent… but failed completely, which made this hard to understand at some point.

  11. I read that the heart contains neurons that also function like the ones in a brain and that that is partly the reason for transplanting memorys from a donator to the receptor.
    Did you hear about that?

  12. I think that the addition of pro and pre biotics into someone's stomach would also increase that persons uptake of certain vitamins which would further decrease stress levels and anxiety. It's a synergistic effect. Also when you are starving the "neurones" in your stomach can really start to change how you think. You will become more ruthless in how you aquire food. As a survival precaution.

  13. Anyone else notice the subliminal advertising she is doing for Taco Bell?

    She mentions a craving for Tacos and shows a taco with the Taco Bell Chihuahua. Then her sweater has the Taco Bell logo on it. Its faded so its not blatantly obvious but its still flashing its message to your brain.

  14. Ernest Becker couldn't have been that wise, speaking of "the fatality of death" as such phraseology is redundant. I've never seen a death that wasn't fatal. I believe he may have meant the stark finality of death.

  15. So eating yogurt for breakfast on test days could prevent me from panicking during the test? You may have just saved my whole week!

  16. Guys have a third brain located below the second brain. It's a small brain with only one thing on it's mind really and it can be very hard to ignore at times.

  17. Can't find any research articels on probiotics and anxiety on the NIH site ww.ncbi.nlm.nih.gov/pubmed.
    Can you give us some references, please?

  18. The bacterias living in our intestine outnumber our own cells by a factor of 10.

    As you mentioned, we have two nervous systems (autonomic vs voluntary), two circulation systems (lymphatic vs iron based actively pumped blood), two immune systems (the default, killing directly but inefficient, the second learn to recognize past infections, send tag team which infiltrate it's way thru layers of cells seeking gradient then soldier killing efficiently anything with the tag. Also, in the new system, some soldier just throw peroxide bombs, then fly away to avoid being damaged by own chemical weapon.

  19. Thank you for your interesting video. I've heard there are more seretonin receptors in your gut than in your brain. Whether this is true or not I don't know.

  20. I really appreciate the academic references. There are other channels which have made statements on this topic which are pretty over the top, but this discussion seems grounded in reasonable science, and lets us follow up for more information if desired.

  21. It's hard to listen to your gut when you have gastro diseases – honestly, it's hard to tell between intuition and pain sometimes.

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