What Are Neurotransmitters?
Emerging research into the gut-brain axis is reshaping our understanding of mental health, behavior, and cognition, especially in children. At the heart of this intricate system lies the dynamic relationship between diet, neurotransmitters, and the gut microbiome. Neurotransmitters (or what could be called “brain chemicals”) such as serotonin, dopamine, GABA, norepinephrine, acetylcholine, and glutamate are critical chemical messengers that influence everything from mood and sleep to focus, energy, and learning. Intriguingly, the gut microbiome—the vast community of bacteria and other microorganisms residing in our intestines—plays a major role in regulating the production and activity of these neurotransmitters. And at the foundation of it all is diet: the fuel that supports or sabotages this biochemical network.
This article provides a high-level overview of some of the functions of our neurotransmitters and the microbes that can help or impair the production or function of these neurotransmitters. Use this article as resource to help identify microbial friends that may be missing from your child’s gut and foods that can help improve their overall microbiome diversity.
Serotonin: The Mood, Sleep, and Digestion Regulator
Often dubbed the “feel-good neurotransmitter,” serotonin is essential for mood stability, sleep regulation, and digestion. About 90% of the body’s serotonin is produced in the gut, where it helps regulate bowel movements and contributes to feelings of well-being.
- Microbes that support serotonin production include Lactobacillus rhamnosus, Bifidobacterium infantis, Lactobacillus helveticus, Bifidobacterium bifidum, Lactobacillus plantarum, and Bifidobacterium longum. These strains help maintain a healthy gut lining and stimulate serotonin pathways.
- Dietary sources that naturally provide these probiotic strains include yogurt with live cultures, kefir, fermented vegetables such as sauerkraut and kimchi, and miso. Prebiotic foods that feed these beneficial bacteria include oats, green bananas, flaxseeds, asparagus, and garlic.
- Impairing factors: Excessive sugar, artificial sweeteners (especially aspartame), chronic stress, and highly processed foods can disrupt the microbiome and reduce serotonin levels, contributing to mood instability, poor sleep and even constipation in children.
Dopamine: Motivation and Reward
Dopamine is a neurotransmitter associated with motivation, focus, and the reward system. It also plays a role in motor control and emotional responses. Disruptions in dopamine levels are linked to conditions such as ADHD, depression, and addiction.
- Supporting microbes include Lactobacillus plantarum PS128, Lactobacillus rhamnosus, and Bifidobacterium breve, which help enhance dopamine signaling and balance.
- Probiotic-rich foods such as kimchi, natto, tempeh, and high-quality supplements can bolster dopamine production. Prebiotics such as apples, green tea (rich in polyphenols), cacao, and berries provide the polyphenols and fiber needed to fuel dopamine-supporting bacteria.
- Impairing factors: Excess caffeine, alcohol, low-protein diets, and high-fat processed foods interfere with dopamine synthesis and receptor function, leading to decreased enthusiasum, motivation and focus.
GABA: The Calming Messenger
Gamma-Aminobutyric Acid (GABA) is a primary inhibitory neurotransmitter, helping to calm the nervous system and promote relaxation and sleep. Imbalances in GABA are linked to anxiety, insomnia, and even seizures.
- Helpful microbial strains include Lactobacillus rhamnosus, Bifidobacterium longum, Lactobacillus helveticus, Lactobacillus plantarum PS128, Bifidobacterium breve and Lactobacillus brevis.
- Fermented foods like kefir, yogurt, miso, tempeh, and naturally fermented pickles can boost GABA levels. Prebiotics that promote GABA-related microbes include chicory root, Jerusalem artichokes, leeks, and onions.
- Impairing factors: Excess alcohol, processed foods, and diets low in fiber can impair GABA production and increase susceptibility to anxiety, brain fog and insomnia.
Norepinephrine: Alertness and Stress Resilience
Norepinephrine is vital for alertness, energy, attention, and stress response. It helps the brain respond to challenges and plays a role in emotional regulation.
- Microbes that support norepinephrine include Bifidobacterium bifidum and Lactobacillus helveticus, which have been shown to reduce stress and improve alertness.
- Probiotic dietary sources include sauerkraut and other fermented vegetables. Prebiotic foods such as blueberries, spinach, and almonds support the microbiota involved in norepinephrine production.
- Impairing factors: Chronic stress, poor sleep hygiene, and refined carbohydrates can blunt norepinephrine production, reducing resilience, increasing fatigue and contributing to mood swings.
Acetylcholine: Memory and Cognitive Function
Acetylcholine is crucial for memory, learning, and motor control. Low acetylcholine levels are associated with cognitive decline, attention issues, and memory lapses.
- Microbial strains such as Lactobacillus plantarum and Bifidobacterium breve assist in maintaining healthy levels of acetylcholine.
- Probiotic-rich foods supporting acetylcholine production include fermented olives, traditionally fermented sourdough bread, and kombucha. Prebiotics such as egg yolks (a direct source of choline), broccoli, and Brussels sprouts nourish the microbiome and promote acetylcholine synthesis.
- Impairing factors: Diets low in healthy fats, anticholinergic medications, and deficiencies in B vitamins impair acetylcholine production and transmission, affecting mood, cognition, digestion, sleep and muscle function.
Glutamate: Learning and Brain Energy
Glutamate is the brain’s primary excitatory neurotransmitter, essential for learning and memory. It helps form connections between neurons and supports brain energy.
- Supporting microbes include Lactobacillus rhamnosus and Lactobacillus brevis.
- Fermented foods such as miso soup, natto, and kimchi can enhance glutamate production and function. Prebiotic-rich foods such as seaweed, barley, and artichokes support a diverse microbiome that aids glutamate balance.
- Impairing factors: MSG (monosodium glutamate) and other sources of free glutamate in processed foods, poor microbial diversity, blood-sugar crashes and chronic inflammation can cause glutamate imbalances, leading to excitotoxicity, mood, cognitive and energy issues.
Conclusion
A growing body of research underscores how deeply interconnected the gut, brain, and diet are. The microbiome acts as a mediator, influencing neurotransmitter production and signaling through both direct microbial activity and immune and metabolic pathways. For children, whose brains are rapidly developing, the quality of their diet and gut health can have profound impacts on mood, behavior, learning, and long-term mental well-being. By embracing nutrient-rich foods, prebiotics, and probiotics, and minimizing harmful dietary and lifestyle habits, we can nourish not only the body but also the mind—from the inside out.
About Heather Tallman Ruhm MD
Heather Tallman Ruhm MD is the Medical Director of the Documenting Hope Project. She is a Board Certified Family Physician whose primary focus is whole-person health and patient education. She draws on her conventional western training along with insights and skills from functional, integrative, bioregulatory and energy medicine. She believes in the healing capacities of the human frame and supports the power of self-regulation to help her patients recover and access vitality.
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