Our bellies and brains are physically and biochemically connected in a number of ways.
Have you ever had a gut feeling or butterflies in your stomach? Has hunger ever changed your mood? Our bellies and brains are physically and biochemically connected in a number of ways, meaning the state of our intestines can alter the way our brains work and behave, giving a whole new meaning to ‘Food for thought’.
As a nutritionist, microbiologist and neuroscientist, Ruairi Robertson is passionate about the link between our bellies and brains. His research is examining how our intestines and the microbes within them can influence both physical and mental health, and most importantly how our diets influence this relationship.
TED Talk by Ruairi Robertson
Key Takeaways
Imagine this… You have just won ten million dollars in the lottery. You have just eaten the most delicious, warm, chocolate brownie that has ever been baked. You…have just had sex. And you…have just done all three at the same time.
In these situations, our brains produce chemicals called neurotransmitters which give us these great feelings of energy, excitement and happiness. And without such chemicals inside of us, we wouldn’t feel such emotions during such pleasant circumstances.
So instead, imagine this: You’ve just been fired. You’re about to sit an exam. You have depression. In these situations, our brains, instead, produce different chemicals, making us feel stressed and anxious.
The highs and lows of life are controlled by our emotions and these chemicals in our brains. This vital organ inside all of us that controls everything that we feel, think and do.
We each have a second brain, another organ in our body which controls as much of our physical and mental functions as the brain in our heads, and which may be the key link between modern disease epidemics, globally, from obesity to cardiovascular disease, maybe even to mental health.
Everyone has something in common. We all spent the first nine months of our existence inside our mothers’ wombs. And this was essentially a sterile environment where no other living things existed, just you. But as you emerged into this world, you were smothered in an invisible coating of microbes, friendly microbes from your mother’s birth canal.
And these bacteria grew to form what is now a three-pound invisible organ inside your large intestine, the same weight as your brain, and which has become known as our microbiota, or microbiome.
And this invisible organ has grown so much, in fact, that right now, 90 per cent of the cells in your body are bacterial cells; only ten per cent are your own human cells. So you are more bacteria than you are human.
This ecosystem of microbes in your gut is as diverse as the Amazon rainforest. Thousands of species all with different functions. And your health is incredibly dependent upon the life and vibrancy of this rainforest.
Your gut bacteria digest certain foods, produce essential vitamins and hormones, respond to medicine and infections, control your blood sugar and blood cholesterol levels.
Meaning the types of bacteria in your intestines can significantly control your risk of certain diseases from obesity to diabetes, maybe even osteoporosis. They’re involved in just about every process in your body. They function almost as a second brain.
We must restore our relationship with gut microbes for our own physical health. We’ve still completely underestimated their role as our second brains.
Our bellies and brains are physically and biochemically connected in a number of ways.
1. Our intestines are physically linked to our brain through the vagus nerve which sends signals in both directions. Interestingly, even though if this is severed, our intestines can still continue to function fully without a connection to the brain, suggesting they have a mind of their own.
2. Our brains are made up of a hundred billion neurons which continuously send messages to tell our bodies how to work and behave. Well, interestingly, our guts have a hundred million neurons.
3. Our microbiomes are the centerpoint of our immune systems, meaning a disturbance down here can cause subtle immune reactions all around the body, which if prolonged, can affect brain health.
Do we remember our chocolate-eating, lottery-winning womanizer here in the front row? He demonstrated for us the neurotransmitters are these chemicals that can change the way we think and behave, and how we feel.
As it turns out, most of these neurotransmitters are also produced in our gut, none more so than serotonin, nature’s antidepressant, 90 per cent of which is produced in our intestines, less than ten per cent is produced in our brains.
Meaning the types of bacteria inside of you may control the way that you think and behave. Has stress ever messed with your insides? Have you ever had a gut feeling? Or butterflies in your stomach? You may have to think twice about that.
In the APC Microbiome Institute in Ireland, we’re fascinated in this link between our belly and our brains, and we research how our modern diets and lifestyles are impacting this gut-brain relationship, and how we can design interventions to target the microbiota in order to prevent and treat chronic diseases.
- For example, we’ve shown that the types of fats that you eat throughout life can drastically change the types of bacteria that decide to reside in your intestines.
- In addition, we’ve shown that by feeding specific strains of bacteria, it can enhance memory, stress behavior, and stress hormone levels in animals.
- And in addition to a number of other researchers worldwide, we’ve identified lists of foods that can act as prebiotics, or foods that can stimulate the growth of healthy bacteria inside our intestines.
To me it’s fascinating that our health is so dependent not only upon nourishing ourselves, but upon feeding other living microorganisms inside of us, meaning future strategies to target and treat chronic diseases, including brain health, may depend on targeting or feeding our gut microbiomes.
As humans, we all need to adopt a greater appreciation for the microbes inside of us. The incidental war we’ve waged on bacteria over the last century has led to bacterial extinction and sparked an epidemic of modern plagues.
We can restore our relationship with microbes, and how this can be used to prevent and treat chronic diseases. Whether it’s by educating ourselves on the risks and benefits of C-sections, restricting unnecessary antibiotic use, or by adopting a gut-friendly diet and lifestyle, we can all support the life of microbes that we’ve evolved to live alongside.
So imagine this: Imagine you’ve just eaten chocolate, or won the lottery, sat an exam or just been fired. Imagine your thoughts, your emotions, your behavior, and your health could be controlled by a hidden organ that you knew little about. To not only prolong healthy human life, but healthy microbial life.
We can all contribute to this fight worth fighting for our own health, but more importantly, for future generations’ health by restoring the relationship between microbe and man. There is some food for thought.