The Gut-Brain Connection

Have you ever experienced nervous butterflies before a job interview or important presentation? Or how about that “pit in your stomach” feeling when you realize you’ve just made a big mistake? These feelings aren’t just in your head. Underlying these sensations is a vast network of over 100 trillion microbes in the digestive tract and over 100 million neurons that line the gut. In the past, scientists believed this network was simply responsible for digestion. But it’s much more than that. As researchers turned their microscopes to the gut, they uncovered something remarkable: the gut behaves like a second brain.

According to Harvard Medical School, “a person’s stomach or intestinal distress can be the cause or the product of anxiety, stress, or depression.” Studies have found that people with mood disorders often have a disrupted gut microbiome. But how is it possible that your gut can have such a profound impact on your mood.

It doesn’t help you write poetry or solve complex problems. Instead, the gut heavily influences your mood. Perhaps even more so than your brain. On the flip side, your mood can have a substantial impact on your gut. So your gut and brain are intimately connected to one another. Scientists call this the gut-brain axis or connection. While research is still in its infancy, scientists have found that your gut produces around 50% of all dopamine and an estimated 95% of all serotonin. Both dopamine and serotonin are neurotransmitters that play a pivotal role in your mood. When you have high levels of these neurotransmitters, you feel happy and motivated. When they are low, you can feel deflated, stressed, and unhappy. With that in mind, if your gut is not functioning as it should, it can negatively impact your mood by disrupting the production of these important neurotransmitters. The gut and brain have a bidirectional relationship. This means not only can your gut influence your mood, but your mood can also impact your gut health.

If you’re chronically stressed, for example, it can decrease the tone of your vagus nerve which is connected to your entire digestive tract. The vagus nerve plays a role in telling the brain what’s going on in the gut and controls a variety of digestive functions. When the tone of the vagus nerve is low from chronic stress or other factors, studies have found that it can trigger the symptoms of IBS such as bloating, gas, cramping, constipation, and fatigue. This would explain why so many people experience digestive issues when they are nervous or stressed.

There’s also evidence that stress can contribute to leaky gut syndrome which can result in chronic inflammation and cause your immune system to attack your own body. When the gut-brain axis is dysregulated, things can go from bad to worse. As your gut health negatively impacts your mood, the increased stress can cause your digestive system to react, causing digestive distress.

The good news is that you can take advantage of the gut-brain connection. By focusing on improving your digestive and mental health at the same time, you can turn it into a positive cycle for upgrading your well-being. Even if you’re only concerned with boosting your mood, both your mental and digestive health must be addressed due to their powerful relationship. In fact, in recent years medical experts have successfully used a strategy of optimizing gut health to help patients overcome mood disorders.