The Gut-Brain Connection
- July 1, 2024
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).
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.
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.