Functional Medicine & The Gut-Brain Connection: What It Is + How to Support It

Ever felt nauseous before a big presentation? Or felt “butterflies in your stomach” when you met someone new? That’s no coincidence—that’s the power of your gut-brain connection.

Your brain and gut talk to each other constantly. They’re connected by a rich network of nerve cells known as the gut-brain axis. What happens in your brain affects your gut, and vice versa. That’s why you may get a “gut feeling” about a tough decision or feel a knot in your stomach when stress hits.

In this article, we’ll explain how the gut-brain connection works and how to harness it to support your physical and mental health.

What is the Gut-Brain Connection?

Your brain is connected to all your organs. But your gut is like your brain’s BFF. They have a bidirectional communication network that sends signals back and forth. This two-way crosstalk is known as the gut-brain axis.

Just like you might ask for a friend’s advice when making a major decision, the same is true for your gut and brain. They influence one another. Your brain can affect your digestion, and your digestive system can affect your mood and mental health.¹

But that’s just scratching the surface. Your gut-brain axis can affect many aspects of your health, including:²

Immune function
Hunger and satiety
Metabolism
Food sensitivities and intolerances
Food cravings
Gut motility
Mood
Stress levels
Cognitive function
Sensitivity to pain

That’s why tending to your gut-brain connection can have a big impact on your health and well-being.

Key Players in the Gut-Brain Connection

At a basic level, your gut-brain connection consists of a network of nerves that connect your gut and brain. But your endocrine system also plays a role, secreting hormones that affect stress, hunger, mood, and more.

Here are a few VIPs in the gut-brain axis:

Enteric nervous system (ENS)

The enteric nervous system (ENS) is a network of 200-600 million nerve cells that line the walls of your digestive tract.³ That’s more neurons than anywhere else in your body, other than your brain. This explains why the gut is often referred to as your “second brain.”

The ENS is part of your autonomic nervous system (ANS), which controls bodily functions outside your conscious control. Its job? To regulate digestive functions like swallowing, secreting enzymes, and nutrient absorption. While the ENS works with your ANS, it can perform some functions independently from your brain.

Vagus nerve

The vagus nerve is the longest cranial nerve, and the main pathway that connects your gut and brain.⁴ Its branches wind through your body, connecting your brain to your digestive system and other organs. Think of it like an information superhighway. It sends signals in both directions, helping your gut and brain communicate.

The vagus nerve is part of your parasympathetic nervous system, known as your “rest and digest” response. This branch of your ANS calms the stress response and helps you relax. Stimulating the vagus nerve can help you shift out of “fight or flight” mode and feel more at ease. More on this later.

Gut microbiome

Your gut is home to over 100 trillion microbes, known collectively as your gut microbiome.⁵ These tiny organisms aid digestion, but also influence your gut-brain connection. They produce mood-boosting neurotransmitters like serotonin, dopamine, and GABA.⁶ In fact, 50% of dopamine and 90% of serotonin are made in the gut!⁶ That’s why when your gut health is off, your mood can take a hit, too.

Your gut microbiota also produces short-chain fatty acids (SFCAs), which offer a wide range of health benefits. One standout is butyrate. It’s been shown to lower inflammation, support a healthy gut barrier, and increase levels of GLP-1—the same appetite-reducing hormone that drugs like Ozempic mimic.⁷

Gut Health and Mental Health

There’s a strong link between gut health and mental health. People with an imbalanced microbiome (dysbiosis) are more likely to suffer from depression and anxiety.⁸ On the flip side, people with a healthy gut are more likely to have a healthy nervous system.

Digestive disorders like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are also closely tied to mental health.^9,10 Research shows people with these conditions are much more likely to develop depression and anxiety.

Fortunately, there’s a lot you can do to fix your gut-brain connection and bolster your mental and physical health.

How to Support Your Gut-Brain Axis

Eat a gut-friendly diet

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Supporting your gut-brain axis isn’t just about eating yogurt or taking a probiotic. A functional medicine doctor can help you create a targeted, personalized plan that addresses the root causes of imbalance—rather than just managing symptoms. Eating a nutritious diet is one of the best ways to tend to your gut. In fact, making healthy dietary changes can shift your microbiome in as little as 3 days!¹¹

Skipping processed foods in favor of whole foods is a good place to start. But fiber is a top priority for gut health, too. It keeps your digestive system moving and nourishes your gut microbiome. Be sure to add high fiber foods like fruits, veggies, whole grains, and legumes to the menu.

Speaking of menus, try to mix things up. Eating a wide range of foods promotes microbiome diversity—the number of bacterial species that live in your gut. Generally, the more diverse your microbiome is, the better your gut health will be.¹¹ So consider stepping out of your comfort zone and trying new foods.

Here are some gut-friendly foods to add to the mix:

Omega-3 fatty acids. Omega-3s lower inflammation, support brain health, and promote the growth of good bacteria in your gut.¹² Omega-3 rich foods include fatty fish (e.g., salmon, sardines, tuna), walnuts, chia seeds, flaxseed, and hemp seeds.
Fermented foods. Yogurt, sauerkraut, kimchi, and other fermented foods contain strains of live, friendly bacteria. Eating more of them is an easy way to replenish the “good guys” in your gut and increase microbiome diversity.¹³
Prebiotics. For your friendly flora to thrive, they need to be well fed. Enter prebiotic foods like onions, garlic, asparagus, bananas, apples, oats, and chicory. They contain special fibers that feed your gut microbiome.
Polyphenols. These plant compounds inhibit the growth of “bad bacteria” while promoting the growth of friendly strains.¹⁴ Polyphenol-rich foods include berries, dark chocolate, green tea, olive oil, and certain nuts like pecans and hazelnuts.

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Strengthen your vagus nerve

A healthy gut-brain connection depends on a strong vagus nerve. The good news? You can tone your vagus nerve intentionally, just like a muscle.

Each time you stimulate your vagus nerve, it activates your rest and digest response. This helps you let go of stress, feel more relaxed, and digest your food better. Win-win!

Here are a few activities that can help improve vagal tone:

Slow, deep breathing
Singing and humming
Gargling
Exercise
Cold water exposure
Laughter
Meditation
Yoga

For a deeper dive into vagus nerve stimulation, check out this article.

Address gut imbalances

A healthy microbiome is essential for your gut health and overall well-being. When the bad bugs outnumber the good, it can affect your digestion, mood, metabolism, immune function, and more.

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Pathogens like viruses, yeast, parasites, and bad bacteria can all create chronic inflammation. If left unchecked, this can damage the gut lining and lead to digestive issues like bloating, gas, diarrhea, and constipation. But it can also take a toll on your mood. Remember, many mood-boosting chemicals like serotonin and dopamine are made in your gut.

This is where functional medicine can make a real difference. Instead of masking symptoms, a functional medicine doctor works to uncover and address the root causes of imbalance—supporting long-term healing and resilience.

That’s why Anchored in Health is proud to offer comprehensive gut health testing, including the Gut Zoomer test by Vibrant Wellness. It provides a comprehensive look at your gut health, assessing over 170 species of microbes, as well as digestive health and inflammatory markers.

If you’re experiencing digestive issues and feeling stuck, gut health testing can help get to the root of your symptoms. And if you’re looking for a functional medicine doctor in the Chicago area, our team is here to support you every step of the way—with science, compassion, and care that honors the connection between your gut and brain.

If you’re experiencing digestive issues and feeling stuck, can help get to the root of your symptoms. Live in the Chicago area? Contact us to learn more.

Elevate Your Gut Health & Mood with Functional Medicine in Orland Park, IL

If you’re dealing with digestive issues, chronic stress, or mood imbalances, your gut-brain connection may be the missing piece. At Anchored in Health, we take a root-cause approach to help you feel better, mentally and physically.

Our functional medicine doctor uses advanced testing to assess your gut health. From there, you get a personalized roadmap that supports your microbiome and nervous system.

Live in the greater Chicago area and ready to get answers? Follow these steps:

Contact us with questions.
Schedule your first appointment with our functional medicine doctor here.
Get your gut and brain in sync so you can feel your best!

Other Holistic Health Services at Anchored in Health in Orland Park, IL

Our Chicago-based wellness clinic offers a variety of services to support your health and well-being. This includes massage therapy, acupuncture, chiropractic care, and the Shape ReClaimed program. We also provide thermography and genetic testing to uncover the root causes behind stubborn symptoms.

Disclaimer: The information provided on this blog is for educational and informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. The content is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you may have regarding your health or a medical condition.

Reading this blog does not establish a doctor-patient relationship between you and Anchored In Health or any of its practitioners. Reliance on any information provided in this blog is solely at your own risk.