Everything You Need to Know About the Gut-Brain Axis

by | Dec 15, 2022 | Gut health

Everything You Need to Know About the Gut-Brain Axis


The gut and the brain are highly connected, and new research shows that the gut-brain axis is an important factor to consider when it comes to health.


Because the gut and the brain are so interconnected, there is potential to help heal gut issues using our brain and to heal brain or mood issues through the gut. Isn’t that amazing?


If that sounds interesting, read on to learn about the gut-brain axis and how you can use this new research to improve your gut and brain health.


Your gut is (partially) controlled by your brain.

As many people know, gut disorders like irritable bowel syndrome (IBS) can cause pain, bloating, and other unpleasant symptoms. These disorders are incredibly common.


Often, gut disorders like IBS don’t have an easily diagnosable physical cause, so treating and finding relief from them can be hard.


Research tells us that our brains control certain digestive processes. For example, thinking about eating can prompt the stomach to release the juices needed to break down food.


You’ve probably also noticed that your gut is sensitive to emotions and have experienced feeling anxious or excited in your stomach.


Several studies show that stress is an important and often overlooked reason for gut issues. Because of this, studies have found that stress reduction techniques can improve gut symptoms.


Your nervous systems

Humans have two “main” nervous systems. The somatic nervous system is one that we can control (like when we move our muscles to walk around or chew our food). 


The other one is the autonomic nervous system. This system controls all body processes we need to survive but can’t consciously control. The autonomic nervous system includes all the processes that happen automatically in the “background,” like breathing.


There are two parts to the autonomic nervous system. The first part is called the sympathetic nervous system, which speeds things up (like when our “fight or flight” reactions kick in). When our sympathetic nervous system is stimulated, our hearts beat faster and we breathe heavier. This is because our body is preparing to fight or flee, so it needs to ensure our muscles get enough blood and oxygen.


The parasympathetic nervous system is the opposite part of the autonomic nervous system. The parasympathetic nervous system is used to slow things down so digestion can occur. The body allows the digestive system to kick into gear by relaxing the heart, muscles, and lungs. That’s why this is called “rest and digest.”


The two parts of the autonomic nervous system interact with the gut. That’s why we can experience gut symptoms when we’re stressed.


The enteric nervous system

In addition to your somatic and autonomic nervous systems, there is a third nervous system called the enteric nervous system or “second brain,” which lives inside your digestive system. It contains 100 million nerve cells (neurons) that communicate with each other using neurotransmitters.


The enteric nervous system is closely linked to the immune system. Germs that enter the body through the mouth end up in the gut triggering the immune system. The immune cells in the gut provide another path for the gut to communicate with the brain. For example, if they detect an infection in the gut, this information is relayed to the brain.


The gut-brain axis

The gut-brain axis is described as the is the link between your gut and brain. Signals pass between the gut and the brain all day, which is why we see a link between digestive symptoms and brain/mood disorders.


Think about it this way. If someone is under a lot of stress, they may activate their “fight or flight” response (i.e., the sympathetic nervous system). Remember that when the sympathetic nervous system is activated, it slows digestion down for the energy to be used to fight or flee.


What’s interesting about this stress response is that the same physical reaction appears regardless of whether the threat is real. That means your body will react the same way to a life-threatening situation and a looming deadline – it can’t tell the difference between the two.


As many people know, negative emotions like fear, sadness, anger, and anxiety can cause unpleasant digestive symptoms, like pain, nausea, and other issues. It’s also known that experiencing frequent digestive issues can affect stress levels and moods. It becomes a vicious cycle of gut symptoms and stress.


How to eat for better gut and brain health

One of the ways diet affects health is through the gut microbiome. Your gut microbes thrive on fiber, so including a wide variety of plant-based foods is an excellent way to keep your friendly gut microbes happy. Try to include various plant-based foods, like fruits, vegetables, nuts, seeds, legumes, and whole grains. 


For people following the low FODMAP diet, eating enough high fibre low FODMAP foods is essential for nourishing and maintaining a robust microbiome.


Fermented foods like yogurt, kefir, and sauerkraut are good choices because they contain health-promoting bacteria. Try to include these foods in your diet regularly.


In addition to foods promoting a healthy gut microbiome, some foods can harm your gut microbiome. Reducing your intake of red meat and sugar can be beneficial because limiting these foods can lead to a healthier gut by increasing the diversity of your gut microbiome.


Eating when your mood is low.

Preparing a meal can be impossible when dealing with a low mood. These tips can help you eat well when not feeling great mentally.


Use grocery delivery services.

When your mood is low, often leaving the house is the last thing you want to do. Luckily, grocery delivery services have become more widespread in recent years.


While it may seem like a splurge to pay an extra $5-$10 for grocery delivery, it’s so worth it. Getting grocery delivery removes the barrier of leaving the house, ensuring you have access to nutritious foods.


Keep a well-stocked kitchen.

Keeping your kitchen well-stocked with nutritious foods will make it easier to pull together a nourishing meal in a pinch. A few handy foods to keep in your kitchen include canned beans, canned fish, pasta, frozen vegetables, eggs, and nut butter. These foods can all be used to pull together a quick and easy meal that’s both nutritious and satisfying.


Prepare emergency frozen meals.

When you’re feeling mentally well, consider doing a bit of meal planning and prepare extra portions of meals that you can freeze and keep on hand for the more difficult days. Meals like fried rice, stew, chilli, curry, and soup all freeze well and easily in large batches.


Order nutritious take-out

There’s nothing wrong with ordering take-out. Try to order a meal that includes a source of protein (like beans, chicken, fish, or meat) and some vegetables to ensure the meal is satisfying. Salads and burrito bowls are great options!  Check out my post on low FODMAP eating out to help you choose IBS-friendly restaurant fare.


Stress management for gut and brain health

In addition to diet, stress reduction techniques or psychotherapy may benefit people who experience gut symptoms. It’s thought that these techniques are effective because they promote the parasympathetic “rest and digest” response.


Here are a few techniques that you may find helpful:

· Guided meditation

· Deep breathing exercises

· Mindfulness

· Gut-directed hypnotherapy (for example, the Nerva app)

· Yoga


If you’re struggling with gut symptoms, incorporating these techniques into your routine may help improve your gut symptoms and mood.


Final thoughts

Our bodies are incredibly complex, and the gut-brain axis is a prime example of just how interconnected the different parts of our bodies are. Research is starting to show that what we eat can improve our gut health, brain, and mental health. Plus, stress-reduction techniques have been shown to reduce digestive symptoms.


If you want a plan to help, you eat – and enjoy – more of the foods that help your gut and your brain, consult a Registered Dietitian who can provide personalized, evidence-based nutrition advice for your health, lifestyle, and goals.


Book a free discovery call to see if my services can help you with your health goals!

Get in touch with Keren and book a free 15-minute discovery call today!

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