The Gut-Brain Axis Explained
The gut-brain axis is a term for the communication network that connects your gut and brain. If you’ve had a “gut feeling” or felt butterflies in your stomach, you were receiving signals from your second brain – your gut, that is! The gut is usually associated with the digestive system. However, research shows the gut has the power to regulate inflammation and immunity.
No wonder we feel queasy during a presentation or right before a date! The gut and brain are interdependent: your gut bacteria influences your mood and your mood influences your gut bacteria.
The gut resides in the enteric nervous system (ENS). It is independent of the central nervous system. The gut is made up of two thin layers with over 100 million nerve cells in them! These cells line the gastrointestinal tract. Moreover, it controls blood flow and secretions to support digestion in the gastrointestinal tract. Additionally, these neurons help us “feel” what is happening inside the gut.
Since the gut is equipped with its own senses and reflexes, studies suggest it can control gut behavior independently of the brain. Our second brain bears the responsibility of digestion to prevent us from consciously performing the act.
How are the Gut and Brain Connected?
Vagus Nerve and Nervous System
The Vagus Nerve is one of the most important messengers in your body. It connects your gut and brain and sends signals in both directions. It plays a huge role in our parasympathetic nervous system (rest and digest). In fact, it constitutes 80% of our parasympathetic nervous system! Chronic stress or trauma can prevent the Vagus Nerve from supporting our digestive system. Without the help of this nerve, gut issues can arise.
Neurotransmitters
These chemicals are produced in the brain and control feelings and emotions. Did you know 90% of serotonin is actually made in the gut? Serotonin contributes to happiness and controls your body’s internal clock.
Your Gut Microbes also produce a neurotransmitter called GABA, which helps control feelings of fear and anxiety. These microbes also produce many other chemicals that influence the way your brain functions. For example, they produce short-chain fatty acids such as butyrate, propionate, and acetate. These short-chain fatty acids influence our appetite.
Impact on Mental Health
Most of our emotions are influenced by nerves in our gut. Around 90% of serotonin, which regulates mood, is produced in the gut! According to Harvard Health Publishing, stress, depression, or other psychological factors can affect movement and contraction of the GI tract.
Research shows that inflammation in the gut can contribute to depression. Depression weakens the immune system, which creates a vicious cycle. Inflammation also influences the brain and cognition. In fact, more than 20 percent of inflammatory bowel disease patients displayed depressive behavior.
Causes of Gut-Brain Imbalances
1. Stress
We face countless stressors on a daily basis. Our nervous system is meant to protect us from imminent danger. The most popular analogy is that of a saber tooth tiger. Our ancestors would occasionally go into fight-or-flight in response to a threat like a tiger. However, the stressors we face today are much more chronic. For example, getting cut off while driving and being impatient while waiting in line at a store can knock the body out of homeostasis. We create an environment for inflammation to thrive with elevated levels of cortisol.
2. Poor Diet
Food is information! As the saying goes, “you are what you eat.” While this sentiment is true, we are actually what our bacteria eats. Ultra-processed foods can wreak havoc on your gut. In addition, what you consume determines the quality of microbes in your gut.
3. Environmental Toxins
On a daily basis, we are exposed to countless environmental toxins. While some toxins are unavoidable, you can take steps to reduce your exposure. Heavy metals found in your water supply and food substances can disrupt the gut. Always make sure companies you purchase products from conduct third-party testing for heavy metals.
4. Frequent Use of Antibiotics
Antibiotics can directly impact the populations of bacteria in our gut. In many cases, antibiotics are medically necessary. However, the overuse of oral antibiotics can destroy the microbiome, resulting in dysbiosis or gut imbalance.
Foods that Support the Gut-Brain Axis
Whole Foods
The gut microbiome responds and changes depending on the food you consume. Eating refined carbohydrates like white bread, chips, and pastries can alter your gut health. If your gut is compromised, so is your immune system. Focus on what you can add to your diet: whole, unprocessed foods can improve your gut and brain health.
Probiotics
Probiotics are a certain type of friendly bacteria that provide health benefits when eaten. Focus on getting probiotics from whole sources. Think of probiotic foods as fermented foods. Fermented foods contain helpful microbes such as lactic acid bacteria. Here are some great sources of probiotics:
- Kimchi
- Yogurt
- Kefir
- Miso
- Sourdough
- sauerkraut
Prebiotics
Prebiotics are dietary fiber that feeds the friendly bacteria already in your gut. Essentially, they are carbs your body cannot digest. Prebiotics are like fertilizers that stimulate the growth of healthy bacteria in the gut. Here are some prebiotics your gut microbes will love:
- Garlic
- Artichoke
- Onion
- Apple
- Asparagus
- ripe banana
Omega-3 Fats
These fats are essential for brain health as the human brain is 60% fat! EPA and DHA are the forms of omega-3 that are vital for normal brain functioning. Some great sources of omega-3 fats include:
- Fish & other seafood (especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines)
- Nuts and seeds (such as flaxseed, chia seeds, and walnuts)
- Spirulina
High-fiber foods
Think of fiber as a chimney sweep: it sweeps the colon out and removes unwanted substances. Eating foods high in fiber can optimize the gut-brain axis. Sources of fiber:
- Whole grains
- Nuts
- Seeds
- Fruits
- Vegetables
Polyphenol-rich foods
Polyphenols are plant chemicals that are digested by your gut bacteria. In fact, polyphenols have the potential to improve cognition and increase healthy gut bacteria. Sources of polyphenol:
- Cocoa
- Green tea
- Olives
- Coffee
Key Takeaway
The gut and brain are typically viewed as two separate entities. However, this perspective cannot be further from the truth. The gut-brain axis describes the bi-directional communication they have. Additionally, they have a mutually beneficial relationship: if one is thriving, so is the other. There are many different factors that contribute to gut-brain imbalances, which is why it is important to seek support or naturopathic consulting. Through lifestyle changes and accountability, you can achieve the health of your dreams!
Our DesBio Intestine Restore provides support for the intestines and overall digestive health. Mucilaginous herbs help soothe inflamed and damaged tissues. It can provide quick digestive-relief and can support the gut-brain axis.
In order to ensure that you are using supplements and herbs safely and effectively, we recommend scheduling an appointment with a Naturopathic Practitioner. A Naturopathic Practitioner can help you decide what herbs are right for you and help ensure that you are maximizing their benefits.
