Have you ever felt butterflies in your tummy before taking a big leap of faith? And where does the expression “Go with your gut” come from?
Our gut (the organs that make up our GI tract) is often referred to as our “second brain.” While it can’t file your taxes or solve for Y, it does send messages to your brain that affect mood, immune system function, hormones, and metabolism.
Many aspects of our diet and lifestyle affect the communication pathway between our two “brains,” and the good news is there are lots of things you can do to ensure they’re communicating effectively. When that communication is strong, you feel your best – both mentally and physically!

The Gut Microbiome
Inside your gut, there are trillions of fungus, bacteria, and other microbes. These “good bugs” aid in digestion and play a role in your immune system, heart health, and brain function, too! The more diversified these bacteria are, the better your overall health.
When the gut microbiome is under stress, though, there’s a disproportionate number of unhealthy bacteria. This can lead to health concerns like irritable bowel syndrome (IBS), diabetes, depression, and other mental health disorders.
How does your gut communicate with your brain?
Several ways, actually!
Physically, they are connected by the vagus nerve. This nerve sends signals in both directions, keeping your two brains in constant communication. It is responsible for hunger, elimination, gallbladder function, and intestinal blood flow. This nerve also relates to our rest and digestion. (We’ll be talking more about the vagus nerve later on in this series, arming you with tools to stimulate it, so stay tuned!)
They’re also connected through chemicals called neurotransmitters, which are responsible for your feelings and emotions. It is estimated that nearly 90% of the neurotransmitter “serotonin” (responsible for happy feelings) is produced in the gut! That means your mood is greatly affected by what’s happening in your tummy and by the food you consume. (Isn’t that crazy cool?)
Thirdly, your gut and brain are connected through your immune system. Around 70% of the body’s immune system is housed in the gut.
Diet & Lifestyle
Here are some things you can try to make sure our two “brains” are in top-notch communication:
- Eat a diverse diet, consisting of foods that are
- rich in Omega-3 fats (fish like salmon, tuna, and sardines; and nuts and seeds)
- fermented (like probiotic yogurt, kefir, sauerkraut, kombucha, and kimchi)
- high in fiber (such as whole grains, nuts, seeds, fruits, and non-starchy vegetables)
- complete with proteins and fats
- Take a probiotic supplement. This will add the “good bugs” back into your gut! (Anna’s personal fave is this one.)
- Eat plenty of prebiotic foods to stimulate the growth of prebiotics in your gut and colon. Examples include chia seeds, flax seeds, greens, garlic, bananas, apples, etc.
- Only take antibiotics when absolutely necessary. Antibiotics, while often important tools for killing an infection caused by “bad bacteria,” also wipe out the majority of the “good bacteria” living in your gut. (Be sure to take your probiotic and focus on gut-friendly foods while you’re taking antibiotics!)
- Take an active role in managing your stress. Chronic stress can lead to intestinal permeability (or “leaky gut”), which means the gut barrier has become leaky. Inflammatory toxins and other materials which SHOULD be excreted can then pass into your bloodstream.
Interested in learning more? Here’s a great episode of the Rich Roll Podcast to listen to, digging more into the microbiome.