The gut and brain are constantly communicating, so increased stress can affect digestion, and poor digestion can affect mental health.

Key takeaways

• The gut-brain axis helps the brain and the lining of the gut pass messages back and forth.
• Microorganisms in the gut impact the types of messages the brain receives. When you’re stressed, the gut produces fewer feel-good chemicals.
• Eating a balanced diet with fiber, whole grains, prebiotics, and probiotics may help improve gut health and mood.

The gut-brain connection: How gut health affects your mood

Have you ever been so stressed during a Saints game that your stomach hurts? Or maybe you’ve felt tingly “butterflies” in anticipation of your favorite summer concert. Both feelings are examples of how the gut and brain are connected (also called the gut-brain axis). In other words—how you feel affects your gut, and vice versa.

Researchers continue to study the relationship between gut health and mental health. Here, we review some of the findings so far.

What is the gut-brain axis?

The gut-brain axis is the two-way communication between the central nervous system (the brain and spinal cord) and the enteric nervous system (the lining of the gut). The gut, sometimes called the “second brain,” physically connects to the brain through the vagus nerve. It also connects to the brain by sending messages with chemical substances known as hormones and neurotransmitters.

The messages that pass between the gut and brain depend on the bacteria and other microorganisms living in the gut (known as the gut microbiome).

How does gut health influence feelings and emotions?

Researchers have determined there’s a strong relationship between gastrointestinal (GI) symptoms like heartburn and indigestion, and mental health problems. For example:

• It’s common for those with irritable bowel syndrome (IBS) to have anxiety or depression.
• Long-term inflammation in the gut can make it harder for the brain to regulate moods.
• Some foods can cause people to have brain fog, become tired, or be more irritable.
• The most common side effects of antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), are GI-related, including nausea and diarrhea.

One reason an unhealthy gut can affect mood is that a diverse gut microbiome makes chemicals that are essential for mood regulation—like serotonin, dopamine, and gamma-aminobutyric acid (GABA). When the gut produces less of these hormones and neurotransmitters, it affects how we feel.

Not only does gut health affect mood, but mood affects gut health. High stress levels and poor mental health can disrupt our digestion. That’s because stress triggers our fight or flight response. Basically, the brain tells the body there’s a threat and releases lots of hormones. These hormones can change how quickly or slowly food moves through the digestive tract. So, if you’re stressed, you might experience diarrhea or constipation, nausea, or stomach pain.

What are ways to support a healthy gut-brain connection?

There are many ways to support a healthy gut-brain connection, but results vary by person. You should find what works best for you based on your gut health and mood.

Many researchers suggest adjusting what you eat before you try other therapies or supplements:

• Add colorful fruits and vegetables to your plate.
• Consume less red meat in favor of lean proteins and seafood.
• Eat plenty of fiber and whole grains.
• Focus on whole foods instead of ultra-processed foods that can disrupt gut bacteria.
• Incorporate foods with probiotics, such as plain yogurt.
• Try fermented foods when you can. Examples include kefir, sauerkraut, and kimchi.

Along with eating foods that are good for your gut, it’s also important to manage stress levels. Practice mindfulness, find stress relief through exercise, or try deep breathing. Getting enough sleep and limiting alcohol consumption support both gut and mental health, too.

For long-term GI symptoms or mood issues, consult a GI specialist.

How a GI specialist can help

GI specialists (also called gastroenterologists) are gut experts. If your gut or mood symptoms last more than a few weeks or interfere with daily activities, start by talking to your primary care provider. They can refer you to a gastroenterologist for digestive symptoms or conditions that require specialty care.

At LCMC Health, our gastroenterologists integrate care that considers both digestive and emotional wellness. Learn about digestive care services near you.

Related questions about digestive care

What are signs that your gut health may be affecting your mood?

Your gut health may be affecting your mood if you notice mood changes alongside digestive issues. Look for these signs:

• Brain fog or trouble concentrating
• Constipation or diarrhea that doesn’t go away
• Frequent GI issues, such as bloating, gas, or stomach pain
• Higher levels of anxiety or feeling low
• Random fatigue

What’s the difference between probiotics and prebiotics?

Probiotics and prebiotics are nutrients that promote gut health. Foods with prebiotics (apples, bananas, oats) feed the microorganisms in the gut. Foods with probiotics (yogurt, kimchi, sauerkraut) have microorganisms that support the ones already in your gut.

How do anxiety and depression affect the gut?

Anxiety and depression can trigger a stress response in the body, which causes the gut to release less of the chemicals that make us happy or calm.

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