The gut-mind connection... and your health
Those butterflies in your stomach actually hold some scientific truth.
For a matter of fact, your digestive system contains millions of nerves that branch from your gut, all the way up to your brain. Further to this, your gut produces neurotransmitters that send signals along that gut-brain highway of yours, as well as contains buckets of bacteria that do all sorts of things that impact your thoughts, feelings and behaviours.
They call all this “The Gut-Mind Connection”.
And remarkably, it has been linked to alterations in mood, anxiety, depression, memory, food cravings, eating behaviours and ultimately life choices.
We’ve all experienced them… Those nervous feelings in our guts before a stressful event, like an exam or job interview. Or maybe even that love feeling.... Does warm and fuzzy resonate?
These gut feelings are real.
There is an actual direct connection between your gut and your mind. A good example of this is experienced when we are scared or fear for our lives. Also known as the ‘fight or flight response’, this is our systems way of prepping us for a quick reaction. Adrenaline is released, our heart rate increases, we get a boost of energy, digestion slows down or stops (the gut) and we react... fight or run.
This ‘fight or flight’ response is regulated through the autonomic nervous system, which is a complex network of nerves that extend from the brain to all the major organs within the body, including the gut.
The body’s 2nd brain
The gut has been dubbed the body’s second brain. It contains over 500 million neurons (nerve cells) and plays a crucial role in both our digestive health and body systems, including our minds.
The guts neurons and neurotransmitters are the same as those found in the brain and spinal cord, sharing similar roles and functions.
All the nerves in the gut are collectively known as the enteric nervous system, and they eventually all link up to form a single larger nerve, called the Vagus nerve, which connects directly to the brain. If the vagus nerve is blocked or damaged it has profound effects on your gut health, including alterations in digestion, appetite and eating behaviours.
When you eat food...
When you eat food, the nerves in your gut are stimulated. This triggers the muscles in the digestive tract to contract and move your food along the digestive train. At the same time neurotransmitters, such as serotonin, are released from the gut to communicate messages back and forth to the brain. These messages affect our appetite and our feelings of fullness, as well as regulate the movement of food along the digestive tract.
We are more than human – The gut bacteria
“One linear centimeter contains more bacteria than all the humans that have ever been born.”
The human gut contains up to 3kg of bacteria. These bacteria are referred to as microflora and outnumber our body cells by 10 to 1. There are literally trillions of them, with hundreds of different species. Lucky enough, most live in harmony with us (like a bird on a cow), providing benefits such as assisting digestion, strengthening immune function, as well as producing some essential nutrients.
If pathogenic (bad) bacteria move in and grow in undesirable numbers, they can damage our health. Think gastro or Bali beli.
Vomiting, diarrhoea, pain, inflammation, toilet marathon, etc.
Now as mentioned earlier, the gut has a bunch of nerves, and some of these protrude out into the lumen (gut space), coming into contact with bacteria. This is one of the reasons we get abdominal pain and suffer other unhappy symptoms when we have a gut bug.
Your gut health affects your thoughts, feelings and choices.
Dopamine is a neurotransmitter that helps control the brains pleasure centre, as well as affects our appetite and emotions. Notably, around 50% of our dopamine is produced in the gut, reinforcing the gut-mind link.
Evidence shows that gut bacteria can produce vast amounts of dopamine, influencing appetite, reward, motivation, pleasure and gastrointestinal motility (the movement of food). Further to this, we know that antipsychotic drugs work by antagonising dopamine, which in turn influences mental state. Similarly, anti-nausea drugs also act on dopamine activity, tying the link between dopamine and the gut-mind connection, even tighter.
Serotonin, another crucial neurotransmitter that regulates mood, cognition, memory, sleep, appetite and most importantly food digestion and motility, is also definitively tied to the gut. Virtually all the serotonin produced in the body (~90%) is made in the gut.
Serotonin is a key player in the gut-mind connection with studies conveying a list of evidence to support this link. For example, a deficiency of serotonin is associated with depression, and alterations in serotonin levels are connected to anxiety.
Ever heard of SSRI? They’re one of the most frequently used anti-depressants that work by increasing circulating levels of serotonin. As a result of SSRIs use they commonly cause side effects in the gut, including nausea, altered bowel habits and increased appetite.
Further to this, research has found that certain gut bacteria produce factors that can block or mimic the actions of serotonin, which in turn influences the functions serotonin has on our mood, digestion and appetite. Again, showing how our gut health affects our mind.
Your gut bacteria can influence your mentality
Gut bacteria have been shown to influence mood, sleep, and the way we eat.
They can do this directly, via mimicking the neurotransmitters that are naturally produced by the gut, as well as indirectly, via blocking the actions of some of these neurotransmitters. Some examples:
- Research shows that 50 to 90% of people suffering from Irritable Bowel Syndrome (IBS) also suffer from anxiety, depression or other mental health conditions.
- Studies have found that by changing gut bacteria activity, food cravings can be reduced.
- Other studies have shown that by increasing gut bacteria diversity, food choices and satiety improved, resulting in improved weight management.
Understandably, there is a lot of scientific truth behind your gut feelings, and as time goes on we will see more and more evidence come out to support the gut-mind connection and it’s influence on our thoughts, feelings and behaviours.
And so, you are more than what you eat, you are what you digest, absorb, ferment and cultivate in that gut of yours.
Here’s what you can do to improve your gut health, which in turn should contribute to better mental health...
Eat a diet rich in plant-based foods
Eat a variety of prebiotic and probiotic foods
Manage your stress levels
Move your body each day
And sleep well