Nausea, heartburn, indigestion, upset stomach, diarrhea. If you’re like me you probably sang that in the Pepto Bismol tune. While that’s a catchy jingle, if you have anxiety I bet you know these symptoms very well. Think about a time when you were nervous before a big presentation. Did you have to make several trips to the bathroom? Yep that’s good ol’ anxiety having its fun. Turns out, the relationship is very complex.
You have a physical brain-to-gut nerve called the vagus nerve
The vagus nerve is named after the Latin word for “wandering” as it travels far and spreads out. You’ve probably heard of the central nervous system which is your brain and spinal cord, but there’s also the enteric nervous system located in your gut. The two communicate back and forth with nerve, hormonal and microbial signals. Microbes aka bacteria. Creepy right, all this bacteria just sitting around in your body? Except they’re there to help and are doing anything but sitting around!
These bacteria, of which you have over 2kg, balance blood sugar, keep your immunity up, help process nutrients, and you guessed it…they have a role in mood and stress response. These bacteria produce GABA, an important neurotransmitter for mood and anxiety. It’s inhibitory and similar to pumping the brake pedal to slow down anxiety. Not just part of the brain, GABA also affects gut motility and the rate of nutrient absorption.
There is a bi-directional relationship with stress and bacteria. When you’re stressed or anxious, the amount of good bacteria goes down. But when you work on gut health and increase your good bacteria, it actually lowers the stress response in the body. How? Well, good bacteria in your gut can lower cortisol levels—your main stress hormone and also alter expression of GABA receptors—which helps you feel calm.
Your gut bacteria affects your mood.
There’s loads of species of bacteria in your body, but L.Helveticus and B.Longum have been shown to provide resiliency against stress. L.Rhamnosus has also been studied heavily. This species modifies the GABA system in the brain and leads to decreases in anxiety. It's found in the fermented food kefir, or in many probiotic supplements.
If you want to work on your anxiety, fermented foods should be a key addition to your diet.
Some options are:
Don’t forget about prebiotic containing foods like cabbage, asparagus, sunchokes (aka Jerusalem artichokes) and oats, which feed the good bacteria. I’m a big fan of kimchi (fermented cabbage with spices) as it contains both prebiotics and probiotics.
Stress relief techniques like meditation or yoga are also helpful because remember the relationship goes both ways. Working on your gut health reduces your anxiety, and separately reducing your anxiety and stress can boost your gut health!