Until recently, we didn’t know how much our gut and brain interacted. Some people thought that our brains controlled everything we did, consciously and subconsciously.
They were wrong! It’s now well established how much our gut controls our overall health and wellbeing (especially our mental wellbeing!).
Some of us have a sense that there is a connection because we often feel emotions in our gut. For example, when we’re scared we can get a “knot” in our stomach. Or, feeling sad or anxious can affect our appetite and the number of bathroom trips we need to make. Plus, many digestive issues often come with mood issues.
Recent research confirms a gut-brain connection, a.k.a. “axis.” This microbiome-gut-brain axis is stronger and more different than we had imagined. And with new technology, we’ve been able to study the gut microbes in a way that was not possible just a few years ago.
The noticeable gut brain connections...
There are a lot of interconnections that we’ve seen over the years that point to this microbiome-gut-brain axis.
First of all, our gut’s main job is to digest and absorb nutrients from our food and get rid of waste. There are a lot of nutrient deficiency disorders which have brain and mental health connections. For example, insufficient amounts of omega-3 fatty acids and certain B-vitamins are linked with brain and mental health issues.
Second, many digestive issues seem to be associated with some mental health issues. Higher-than-normal percentage of people with certain bowel diseases (like IBS – irritable bowel syndrome) develop mental health symptoms of depression and anxiety.
Another observation is through those friendly gut microbes; lots of people report psychological side effects after taking antibiotics. Antibiotics are often necessary to treat harmful bacteria. But, they don’t only wipe out those bad bacteria, they also wipe out our friendly gut microbes too.
And what about the effect of stress on our gut? Stress can affect our appetite and even change the gut microbiome. Research shows that altered gut microbes are associated with mental health symptoms.
Also, studies are starting to show that probiotic supplements may help with stress and some mental health symptoms.
As you can see, there are a lot of ways we’ve seen our guts and brains affect each other. But, how can this be? How is it that these microbiota-gut-brain connections actually work?
4 Ways our gut is actually connected to our brain…
1. Your gut has a lot of nerves and is sometimes called the “second brain.” All these 200-600 million nerve cells together form their own nervous system called the “enteric nervous system.” These nerve cells control the intricate functions necessary for your digestive system to do its job - from release of digestive enzymes, to movement of food through it, to the blood flow around it that picks up the absorbed nutrients. The gut uses its own brain to function optimally.
2. Nerve connection between your gut and your brain is through the vagus nerve. This nerve physically connects our gut with our brain. The vagus nerve is part of the nervous system that controls the body subconsciously. The vagus nerve has recently been shown to send about 80% of the information from your gut up to your brain - and not from your brain down to your gut as we previously thought!
3. One of the most famous mood-affecting neurotransmitters, serotonin, is made in the gut. Serotonin is sometimes called the “happy” neurotransmitter because it seems to be lower in people with depression. Research shows that 90% of serotonin is in the gut, not in the brain! It plays an essential role, promoting the movement of food through the gut (peristalsis).
4. Then there are stress hormones like cortisol. Which when released affects other parts of the body, including the gut. Research shows that stress hormones tell immune cells in the gut to secrete compounds that can cause inflammation and tiny “leaks” in the gut (permeability).
Reduce stress for your gut
As we’ve mentioned, gut issues can affect your stress level and moods, but it works the other way around too. If you have gut issues, then reducing your stress may help some of them.
Irritable Bowel Syndrome (IBS) and Inflammatory bowel diseases (IBD) like Crohn’s and ulcerative colitis are considered to be “biopsychosocial” diseases. This means that they’re not just physical issues, but stress plays a key role in them as well. In fact, people with IBS have higher-than-normal levels of stress, depression, and anxiety. And, people who report high levels of stress can go on to develop gut issues.
Stress influences many gastrointestinal functions. These include the microbiota, how well food moves through it (motility), secretion of important biochemicals, as well as how tightly the gut cells adhere to each other (permeability). As well as inhibiting the vagus nerve and contributing to inflammation.
Some experts say that the most effective treatments for IBS are “mind-body” therapies. Mind-body therapies include hypnotherapy, mindfulness, and cognitive behavioral therapy. Individual counselling or participating in support groups can also help.