Did you know that leeches have 32 brains? They have one brain for each segment of their internal structure. And did you know that jellyfish don’t even have a brain? They have rudimentary sensory nerves at the base of their tentacles. Now, what if I told you humans have two brains? Well, technically, we have one brain, but it turns out that our gut health has such an immense influence on our brain and mental health that our gut is often referred to as our “second brain.”
When it comes to gut health, we don’t just see an impact on our productivity and clarity of thought. Our second brain is so powerful that it actually influences our overall wellbeing and our mental health, including mood, depression, anxiety, and more. Let’s explore this well-established, but often overlooked and misunderstood connection between our gut and mental health.
What are we referring to when we say, “the gut?”
The gut includes every organ that participates in digestion, from the intake of food to the process of converting food into energy, nutrients, and waste. It consists of the esophagus, stomach, large and small intestines, gallbladder, liver, and pancreas.
How does gut health affect our overall physical health?
Scientists call our gut-brain the enteric nervous system (ENS). More specifically, your ENS is two thin layers of more than 100 million nerve cells. They line the gastrointestinal tract from the esophagus to the rectum.
Living along the gastrointestinal (GI) tract is a diverse population of bacteria, viruses, and fungi that not only help your body digest food, but they help keep your body chemically and hormonally balanced by interacting with those nerves through hormones and neurotransmitters.
What you eat is important, but if your body can’t breakdown and absorb your food into the nutrients it needs to function, all systems are affected, although in different ways. And because different bacteria serve different functions, too much or too few of certain types of bacteria will cause imbalances.
If you are unable to properly digest dairy products, for example, you’ll often experience bloating, fatigue, gas, and irregular bowel movements. An imbalance can show up as poor skin, dull hair, and brittle nails. Or an imbalance can lower your immune strength leading to infections and diseases. An imbalance in the gut can also lead to disorders and other illnesses such as irritable bowel syndrome, diabetes, and Crohn’s disease.
How does gut health affect our mental health?
It can sound outrageous if you haven’t heard about this connection before. However, to neurologists, scientists, and physicians, gut health is one of the leading areas of inquiry for researchers in the mental health field.
Remember that the gut is lined with nerves that interact with the bacteria, viruses, and fungi of the gut through chemicals like hormones and neurotransmitters, which are a direct line to the brain. A gut with good bacteria and a well-balanced system of flora and fauna means your body and your brain will be more efficient. That means better mental clarity and better mental health.
An unbalanced gut or too much of the wrong bacteria can mean there is a strong likelihood your body and brain won’t be able to cope efficiently, leading to disorders, diseases, and imbalances of hormones and chemicals, both physically, and mentally.
It’s not whether the bacteria is affecting your overall physical and mental health. The connection has been so well established that scientists are now researching which bacteria can be isolated or controlled in order to achieve better mental health. By identifying problematic bacteria, doctors and scientists hope to help patients cope with or even overcome conditions such as irritable bowel syndrome, allergies, and obesity, as well as mental health challenges such as bipolar disorder, schizophrenia, and Parkinson’s disease.
How is gut bacteria changing your mood?
The absence or abundance of certain bacteria has significant influences on your body. Studies are showing that the absence of specific bacteria in the gut of humans and some animals is closely associated with mood disorders and depression.
To illustrate this, consider that most antidepressants are designed to increase serotonin. However, gut bacteria produce dopamine, norepinephrine, acetylcholine, and GABA, all neurotransmitters that are critical for our moods as well as concentration and motivation.
It’s also worth noting the reciprocal relationship between the gut and the brain. Stress can cause mood disorders. However, stress also causes the gut to become more permeable to bacteria, which can cause an imbalance of good and bad bacteria. That imbalance can, in turn, cause or worsen mood disorders. So, the gut-brain system interacts and can cause a spiral that may only be broken with medication for the brain, or supplements and a diet that rebalances the gut.
What about gut health and depression?
As illustrated above, the gut-brain connection is a strong one. Mood disorders, such as depression, can be caused by an imbalance of the gut biome, and the microbiome can also cause or heavily influence whether someone develops depression. It isn’t clear whether the problem originates in the gut or the brain, but it is clear to researchers that these two systems heavily influence each other.
By restoring or altering the gut biome, some patients experience a restorative effect on their mood and related chemical disorders, specifically depression. When comparing the microbiome of healthy patients and those with depression, specific families of bacteria were missing in those with depression. In addition, many with depression have the same imbalance of specific bacteria. For example, too much of a particular bacteria has now linked depression to Crohn’s disease, suggesting inflammation may be behind many mental disorders.
What about the gut health connection to anxiety?
Researchers have been able to identify the gut microbes that have been shown to contribute to anxiety. In fact, people who are diagnosed with irritable bowel syndrome (IBS) are now understood to be more likely to suffer from anxiety and depression because of this specific microbe imbalance. And of course, anxiety is known to worsen symptoms of IBS, leading to a cyclical deterioration of symptoms.
The gut-brain diet: what to eat and what to avoid
Maintaining the right balance of friendly and unfriendly bacteria can help us cope with, overcome, and prevent a myriad of illnesses, diseases, disorders, and dysfunctions when it comes to our physical and mental health. While some pharmaceuticals are currently used to help balance the brain, some foods have been well-established to help or hinder our gut’s microbiome balance, influencing our health.
Foods that contribute to a balanced gut and mental health:
Here are a few best practices, what to eat, what not to eat, and some tips to optimize and balance your gut flora and fauna, specifically for your mental health.
You’re trying to eat and drink foods that will add good bacteria, viruses, and fungi to your system, and that will help the friendly bacteria thrive. A poor diet will encourage unfriendly bacteria while stifling the good.
Consider digestive enzyme supplements to help restore your health. As we age, our natural ability to make our own digestive enzymes decreases. You may choose to stay on supplements to continue to encourage a healthy gut-brain balance.
Choose plant-based foods that will bring balance and encourage colonies of good flora and fauna. Prebiotic and probiotic foods will help to repopulate your gut and encourage growth. Use the 70/30 percent rule, which says that you can eat what you want 30% of the time, but you must be careful and diligent about your diet 70% of the time to remain in good health. This is a useful option because it gives you the freedom to join social events, workplace meetings, and travel without stressing about every meal. It is perfect for people who don’t want to, or can’t, be very strict with their diet. And remember that this varies from person to person, so take into account your current health, medications, lifestyle, environment, and other factors.
Foods that encourage a healthy gut and mental health:
- Fermented vegetables, such as sauerkraut and kimchi.
- Vegetables that are considered non-starchy: asparagus, carrots, garlic, artichokes, leeks, onions, and radishes.
- Fruits that are considered non-starchy: tomatoes, avocado, apples, cherries, grapefruit, kiwi, oranges, nectarines, rhubarb, and coconut.
- Nuts and seeds and related butters or milks
- Sunflower and olive oils.
- Chickpeas and lentils.
- Try to add these raw foods to your diet: asparagus, garlic, onions, or jicama.
- Probiotic foods such as apple cider vinegar, kefir, kimchi, kombucha, miso soup, sauerkraut, tempeh, and yogurt (must be labeled “live or active cultures”).
Foods that will hinder good bacteria while earning poor gut and mental health:
- Processed and fried foods.
- Foods with high amounts of sugar and high-fructose corn syrup.
- Artificial sweeteners.
- Foods that contain trans and hydrogenated fats.
- Large amounts of starchy fruits and vegetables, potatoes, corn, and peas.
- Deli meats because they are high in salt and fats.
- Peanuts, soy, and other legumes, except for chickpeas and lentils.
- High-mercury fish.
- Dried fruit and fruit juices.
- Eggs and dairy, except for butter and ghee.