5 Things You Should Know About the Gut/Brain Axis

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Did you know the digestive system and the nervous system are intertwined? And that they can actually talk to one another? You’ve probably felt this when you get butterflies in your stomach when you’re nervous, or when you have a gut instinct about something (or even when you have diarrhea from anxiety). 

The digestive system has its own nervous system called the enteric nervous system; hence, why the gut is often called your “second brain.” The vagus nerve, which governs the “rest and digest” division of the nervous system, connects the brain to the digestive system. This allows the digestive system and the nervous system to be in constant contact with one another, sending signals back and forth. In fact, they are talking to each other so often that when our behavior changes in a certain way, the brain sends a message that changes our gut bacteria (more on that in a minute). If we have GI distress or dysbiosis in our gut, our behavior can also change (via depression, anxiety, etc.).

Here are five reasons why it is so important to nourish both your gut and your brain, so they can seamlessly work together to help you flourish.

1. All of the neurotransmitters in your brain are also found in the digestive system. For example, even though serotonin is best known for its role in brain health, over 90% of it is made in the gut. It plays an important role in digestive health, helping the muscles of the intestines contract to move food through them (also called peristalsis). This means that if you aren’t properly producing serotonin, you just might be constipated (and you also might be sad about it). Salmon, eggs, and spinach can help to naturally boost serotonin levels if you’re worried you might not have enough.

2. Stress plays a major role in digestive problems. Stress not only heightens your emotions, but your physical body functions as well. If we are in a chronic “fight or flight” state, an imbalance can arise from chronic emotional stress. Stress can send your digestive system into overdrive, either compromising your ability to digest food or shutting it down completely. Continued stress in the body and mind affects the body’s ability to heal, and when anxiety is constant (and stress-reduction is at a low), digestive problems such as ulcers, inflammatory bowel disease, irritable bowel syndrome, small intestine bacterial overgrowth, dysbiosis, constipation, diarrhea, GERD, and even autoimmune issues can occur. Rest and relaxation, as well as activities such as deep breathing, meditation, taking a walk, spending time in nature, yoga, reading, or taking an epsom salt bath, help to restore the balance.

3. Depression and anxiety can be triggered by GI distress. When the vagus nerve is chronically inflamed, it throws both the gut and the brain off balance. 70-90% of people with irritable bowel syndrome experience some sort of mood or anxiety disorders, including depression and panic attacks (Lipski, p.106). They are also more likely to have migraines and/or fibromyalgia. In addition, the good bacteria that live in your intestines are nourished by probiotics, which play a role in producing, absorbing, and transporting serotonin and dopamine. If you have an imbalance of bad bacteria to good bacteria in your gut, you may be experiencing feelings of anxiety. Eating a nutrient-dense, whole foods diet; taking supplements like Vitamin D, zinc, and magnesium; and eating foods rich in probiotics (like sauerkraut, kimchi, kefir, natto, and organic yogurt) can help alleviate feelings of stress, anxiety, and depression.

4. Food really does make a difference! Processed foods are designed to make us crave sugar, (bad) fat, and salt. When we have a craving that’s satisfied, our brains release serotonin and dopamine, indicating that a particular food makes us happy and we want more of it. Additionally, when the body has too much sugar, it leads to spikes and stiff drops in blood sugar levels, causing feelings of anxiety, nervousness, and irritability. This can then lead to GI distress (as mentioned above). Eating a diet rich in organic animal proteins, healthy fats, and lots of fruits and veggies helps to regulate blood sugar, which reduces cravings for sweet processed foods and allows the body to regain balance. 

5. Take your time eating meals by practicing mindful eating. Sit down at a table, without distractions, thank yourself for preparing or purchasing this lovely meal, and spend the next 20-30 minutes enjoying the experience of eating. 20 minutes is not as long as you think – it takes that amount of time for your gut to signal to your brain that it’s had enough food. If you eat really fast, you can end up overeating, and that places a heavy burden on your digestive system.

Did I miss anything? Let me know in the comments!

If you’re looking for an individual approach to understanding your own gut/brain axis, let’s chat! Click here to sign up for my Learn to Thrive Discovery Session!


Lipski, E. (2013). “The Enteric Nervous System: the Second Brain.” In Digestion Connection. Pp. 105-110. New York, NY: McGraw-Hill.

Perlmutter, D. (2013). Grain Brain. Pp. 190-191. New York, NY: Little, Brown and Company.

Scott, T. (2011). The Anti-Anxiety Food Solution. Berkeley, CA: New Harbinger Publications.