The Gut-Brain Connection
For a long time, we thought mental health lived entirely in the brain. Anxiety? Brain problem. Depression? Brain chemistry issue. Fix the brain, fix the person. But here’s the thing. We were kind of looking at the wrong room.
Roughly 90% of the body’s serotonin, a chemical that influences mood, is produced in the gut NOT the brain. While there is a “security gate” called the blood-brain barrier that keeps this physical serotonin from entering the brain directly, your gut acts like a remote control for your mental state. It plays a key role in regulating mood by:
- Affecting tryptophan (the precursor of serotonin)
- Modulating immune responses
- Sending signals via the vagus nerve, the body’s primary gut-brain communication highway
When your gut isn’t functioning well, your mood, energy, and clarity of thought will all take a hit.
Your “Second Brain”
Your gut is sometimes called the “second brain” and for good reason. It contains its own nervous system (the enteric nervous system) that communicates directly with your brain through the vagus nerve and plays a powerful role in mental health. Think of the Enteric Nervous System (ENS) as the brain’s younger sibling who actually runs the household. It manages the entire mood of the house. When the ENS is irritated, maybe from a food sensitivity or chaotic stress, it sends a system error message up the Vagus Nerve. Your brain doesn’t see digestion or leaky gut coming; the vagus nerve sends the anxiety message. This is why focusing on the gut is the ultimate shortcut. In fact, the brain and gut communicate with each other, but 80% of that communication is from the gut to the brain. You’re quieting the alarm at the source. The gut is like an airport control tower for:
- Mood and anxiety
- Cognitive function
- Stress levels
The Role of Lifestyle: Move, Eat, and Breathe
Exercise
Regular physical activity supports gut health by increasing microbial diversity and releasing muscle-derived peptides called myokines, which have anti-inflammatory effects. Exercise also reduces symptoms of anxiety and depression further strengthening the gut-brain connection.
Psychobiotic Foods
Certain foods help your gut microbes thrive and may directly support your mental health. These include:
- Fermented foods: kefir, sauerkraut, kimchi, yogurt
- High-fiber plants: beans, oats, leafy greens, bananas
Manage Stress
Chronic stress can disrupt gut function, leading to inflammation and microbial imbalance. Practices like deep breathing, mindfulness, and earthing can help regulate your nervous system and promote a healthier gut environment.
Prioritize Sleep
Gut microbes follow a daily rhythm, just like we do. Poor sleep disrupts this rhythm and contributes to inflammation, impaired digestion, and low mood. While getting 7–8 hours of sleep is important, the quality of that sleep matters most. Aim for at least 60 minutes of deep sleep and 90 minutes of REM sleep per night to support both your brain and your microbiome. During deep sleep, your gut-brain axis becomes a deep clean vacuum. It’s like the janitorial staff coming into the office at night. If you skip sleep, the trash builds up, and tomorrow’s mood pays the price.
Be Mindful of Medications
Certain medications, especially antibiotics, will reduce microbial diversity in the gut. If you’re taking long-term medications, talk to your healthcare provider about strategies to wean off them and protect your gut health, such as probiotic support or dietary adjustments.
Epigenetics: How Your Lifestyle Talks to Your Genes
Your daily choices, like what you eat, how you move, and how you handle stress, can influence how your genes behave. This is called epigenetics, and it’s like a switchboard for your DNA.
- Eating high-fiber foods? You’re turning on genes that support better mood and digestion.
- Stressed out all the time? You may be switching off genes that help manage inflammation and stress.
By taking care of your gut, you’re also taking care of your mind in real, biological ways.
5 Tips for a Healthy Gut-Brain Connection
- Eat a diverse, protein and fiber rich diet
- Move your body daily
- Manage stress with breathing, meditation, or time in nature
- Get 60 minutes of deep sleep and 90 minutes of REM sleep for good sleep
- Avoid unnecessary antibiotics and ultra-processed foods
We used to think the brain was the commander-in-chief, but we’re realizing it’s more of a mirror. If the gut is inflammed, the brain reflects that as fog, irritability, or low mood. By making the gut your central focus, you aren’t just treating symptoms; you’re changing the biological environment that your thoughts live in.
Don’t get me wrong, I’m not saying eggs every morning will cure clinical depression, but I am saying it’s a lot harder to climb a mountain if you’re wearing lead boots. Healing your gut is like taking the lead boots off. So, maybe start small today: start tomorrow with a tall glass of water, 10k steps, and 5 minutes in the sauna.
Sources
Cleveland Clinic. (n.d.). Serotonin. https://my.clevelandclinic.org/health/articles/22572-serotonin
Cleveland Clinic. (n.d.). The Gut-Brain Connection. https://my.clevelandclinic.org/health/body/the-gut-brain-connection
Psychology Today. (2017). Gut Microbiota May Influence Mood and Behavior, Study Finds. https://www.psychologytoday.com/us/blog/the-athletes-way/201706/gut-microbiota-may-influence-mood-and-behavior-study-finds
Mayer, E. A. (2016). The Mind-Gut Connection – A deeper dive into the science of gut-brain communication.
Dinan, T. G., & Cryan, J. F. (2017). The Psychobiotic Revolution: Mood, Food, and the New Science of the Gut-Brain Connection. National Geographic
Saponaro, C., Madaro, L., & Adamo, S. (2024). The role of myokines in the gut–brain–muscle axis: Implications for mental health and microbial diversity. Nutrients, 16(23), 4032. https://doi.org/10.3390/nu16234032
Koniver, L. (2022). Biological effects of grounding in mice: Impacts on inflammation, oxidative stress, and mood. Biomedicines, 11(1), 57. https://doi.org/10.3390/biomedicines11010057
Sasaki, H., et al. (2025). Gut microbiome composition and its associations with deep sleep architecture in humans. Frontiers in Sleep, 3, 1478129. https://doi.org/10.3389/frsle.2025.1478129