Grassroots Naturopathic Medicine Health Clinic

The Gut-Brain Connection

If you’ve ever noticed that when your gut is off, your mood is off, you are not imaging it! Or, if you’ve eaten something that you know you shouldn’t have, and your mood is low the next day, there is a connection! We call it the Gut-Brain Connection. The gut-brain connection is a bidirectional communication system between the gastrointestinal tract and the central nervous system, and it plays a significant role in regulating mood and mental health.
The Importance of the Microbiome
The gut microbiome, the diverse community of microorganisms living in the digestive tract, influences mood and brain health through various ways.

Neurotransmitter Production: The gut microbiome produces neurotransmitters such as serotonin, dopamine, and GABA, which are crucial for regulating mood. Serotonin often referred to as the “happy hormone”, is heavily involved in mood regulation. Around 90% of serotonin in the body is produced in the gut!

Inflammation and Immune Response: Imbalances in the gut microbiome can lead to increased intestinal permeability (leaky gut) and chronic inflammation, which can impact mood. Inflammation sends the message to the brain, “we’re under attack,” which can greatly impact mood. The gut microbiome also interacts with the immune system, and dysregulation of this interaction can contribute to mood disturbances. Think about how cranky you are when you have a cold.

Short Chain Fatty Acids: Certain bacteria in the gut produce SCFAs through the fermentation of dietary fibers. SCFAs have been shown to have anti-inflammatory properties and influence mood and behavior by modulating neurotransmitter levels and immune function.

Vagus Nerve Signaling: The vagus nerve is a major nerve pathway between the gut and the brain and is an essential part of the parasympathetic, “rest and digest”, nervous system. Gut microbes can impact vagal nerve activity, which can turn on our “fight or flight response.”

Hormone Regulation: The gut microbiome can also influence hormone levels, including those involved in stress response (e.g., cortisol) and mood regulation (e.g., estrogen).

Nutrition and the Brain
Our brain health is directly affected by the foods we eat, which can greatly impact our mood. Here are key nutrients for our brain that we should be consuming every day.

Omega 3 Fatty Acids and Good Fats: The brain is composed largely of fat, so the quality of fat in our diets is critical to brain health. It is important to eat sources of good quality fats such as raw nuts and seeds (a walnut looks like a brain!), oily fish, avocado and olive oil.

B vitamins: B Vitamins particularly B6, B12, and folate, are vital for producing neurotransmitters like serotonin and dopamine, which regulate mood.

Vitamin D: Vitamin D receptors are found in areas of the brain involved in mood regulation. Low vitamin D levels have been linked to depression and seasonal affective disorder (SAD). Your Naturopathic Doctor can test your vitamin D levels. The normal range is 50-200 but optimal vitamin D is closer to 150.

Magnesium: Magnesium helps regulate neurotransmitters and can have a calming effect on the brain.

Antioxidants: Antioxidants are also powerful protectors of brain health. Antioxidants are found in colourful fruits and vegetables, especially berries and dark leafy greens. Dark chocolate and green tea are also great sources of antioxidants.

Amino Acids: Amino acids come from proteins, yet another reason to make sure you are getting enough protein in your diet. Various amino acids act as the building blocks for neurotransmitters.

Supporting Neurotransmitters
Neurotransmitters are the chemical signals that are passed between neurons and can influence our mood, thoughts and behaviours. Many of these can be tested through a functional urine test called organic acids testing.
Serotonin: Regulates mood, appetite, and sleep. Often referred to as the “feel-good” neurotransmitter, serotonin contributes to feelings of well-being and happiness, helps sleep and regulates appetite. Stress has been shown to lower serotonin. Low levels are linked to depression, anxiety, sleep disorders and carbohydrate cravings. A key nutrient in the formation of serotonin is Vitamin B6.

Dopamine: Involved in reward, motivation, and motor control. Plays a significant role in pleasure and reward mechanisms in the brain, and can let us know that we are on the right path. B vitamins and Magnesium are involved in the production of dopamine.

Norepinephrine: Affects attention, alertness, arousal, and the fight-or-flight response, including anxiety. An increase in norepinephrine when we are about to do something new or stressful alerts our brain that we are about to learn. It is a very important neurotransmitter in neuroplasticity or growing our brains. Vitamin C is required for synthesis of this neurotransmitter.

GABA: The main inhibitory neurotransmitter in the central nervous system. Helps to calm the nervous system, reducing neuronal excitability. Low levels are linked to anxiety. One of our favorite nutrients to support GABA is Theanine, an extract from green tea.

Acetylcholine: Involved in attention, learning, and memory. Choline is an essential nutrient in the formation of acetylcholine and is found in egg yolks and soy.
Brain Irritants
Gliadin (the protein in gluten) and Casein (the protein in all dairy) can be potent brain irritants. They can bind to opiate receptors in the brain, and like opiods, can be very addictive. Toxins especially mercury can greatly affect mood. In fact, mercury exposure is linked to depression.
Blood Sugar and The Brain
Insulin resistance and excess blood sugar can irritate the brain as too much glucose in the blood can glycate, or damage, tissues including neurons. Dementia caused by insulin resistance and diabetes is now being referred to as Type 3 Diabetes.
Your Naturopathic Doctor can guide you on how to optimize gut health and your nutrition for optimal mood and brain health.