The Body-Mind Connection: Digestive Health and Your Brain

Have you ever had a gut feeling? Or felt butterflies in your stomach? If so, then you have experienced the gut-brain connection. Some experts once believed that issues in the brain should be handled separately from the gut, but more research is showing that if you want to improve your moods, memory, and brain function, look to the health of your gut.

There’s a good reason why. Let’s start as early as conception, when a baby is in the embryo stage. During this stage, a clump of embryonic tissue separates, and one becomes the brain (the central nervous system, which is the brain and spinal cord) and the other becomes the gut (your digestive system and its enteric nervous system).⁵⁵ Connecting your brain and gut is the vagus nerve—like a telephone line, it carries messages from the brain to the gut and vice versa. It’s also how the bacteria in your gut speak to your brain.

Michael Gershon, professor and chair of pathology and cell biology at Columbia University, has done groundbreaking work on how the gut’s brain, or enteric nervous system (ENS), works. Here are a few key facts^{56, 57}:

The enteric nervous system is embedded in your entire digestive tract from mouth to anus.

It relies on, and in many cases creates, more than 30 neurotransmitters that are identical to those in the brain. (Serotonin is one of these.)

Approximately 70 to 80 percent of your immune system is located in your gut. This makes sense because your digestive system has a big job. It takes in food, water, and bacteria from the outside world and transforms it into nutrients to grow, repair, and maintain the human body. This is the true definition of the old adage, “You are what you eat.”

Approximately 90 percent of the body’s serotonin is located in your gut. Serotonin helps regulate mood, sleep, and learning and can influence your happiness and self-esteem. Serotonin also plays a critical role in digestion by helping to secrete enzymes that help you digest food.

Your gut sends signals to your brain that directly affect feelings of sadness or stress, even influencing learning, memory, and your ability to make decisions. In turn, your brain’s emotions affect your digestive tract. Anger, anxiety, sadness, joy, and other emotions can trigger symptoms in your gut.

Today, more studies are showing that food affects mood and that gut health has a big impact on disease, including osteoporosis, autism, depression, and autoimmune conditions.

Here are three studies that further highlight the gut-brain connection:

1. What you put in your stomach can change your mood. A study by Belgian scientists found that eating fat has the power to lift our emotional state and make us feel happier.⁵⁸ This is why people go for comfort food when they’re upset.

2. Chronic stress can create gut-to-brain cravings. Studies on mice showed that under chronic social stress (like trauma from abuse or bullying), mice would go for high-fat, high-calorie foods and gain more weight than their less stressed counterparts.⁵⁹ Additionally, researchers found that it was the gut telling the brain what to eat and not the other way around. Under stress, the brain produces gherlin, a hormone that stimulates hunger in the brain. Gherlin makes food more exciting to the brain, especially when it is high in fat and calories.

3. Your diet influences your gut bacteria, and your gut bacteria influence your brain. According to neuroscientists, the good bacteria in the gut, which they call “the gut microbiome,” acts as auxiliary DNA. Essentially, what you eat controls the makeup of your gut bacteria, and these bacteria can change how your genes function. In other words, if you are eating a diet that promotes healthy gut bacteria, they in turn can influence a healthy body, regardless of your genetic predispositions.⁶⁰

Another important takeaway from the studies in neuroscience is that your gut bacteria are constantly speaking to your brain. The gut microbiome influences how the brain is wired from infancy to adulthood, along with moods, the ability to learn, memory, and how to deal with stress. When the gut microbiome is healthy, it sends happy signals to the brain; when it’s unhealthy, it can send signals of anxiety. Because of this signaling, neuroscientists are starting to investigate how to manage gut bacteria to treat mood and stress-related disorders, such as depression, IBS, and IBD.⁶¹

In other words, what you eat matters. What you digest or absorb matters. Your gut is responsible for how you feel, how you act, what you focus on, whether you sleep or not, your overall health, and your overall enjoyment of life. When you take care of your gut, you take care of your whole body-mind.

The above is an excerpt from Loving Yourself to Great Health: Thoughts & Food – the Ultimate Diet by Louise Hay, Ahlea Khadro, Heather Dane, published by Hay House (October 7, 2014) available in bookstores or online at www.HayHouse.com.