2018-11-01 / OnCall

The Second Brain

Feeling anxious? It may be all in your gut.
Dr. Brandon Craft

Our brains are the communication centers of the body; their tasks stretch far beyond math homework and speaking to also regulate involuntary bodily functions. But a colony of millions of cells inside our guts are also sending strong signals throughout the body, earning it the nickname “second brain.”

This second brain is made up of millions of cells, including microorganisms and “good” bacteria that make up an ecosystem called the microbiota. Studies show that this microbiota regulates our immune system and protects us from disease, but new evidence also suggests that certain bacteria increase the production of brain-boosting chemicals that preserve mental health.

“The brain sends signals to the digestive system to keep working, and the gut’s second brain manages these processes and releases enzymes to keep it running smoothly. It responds when things are going well, or if something isn’t right,” says Geisinger gastroenterologist Dr. Brandon Craft. All of this communication comes through the nervous system, immune system and even hormones.

On the other hand, if our enzyme or bacterial levels get out of whack due to improper nutrition for the microbiota, we might experience stress or anxiety. No two people have the same mix of components.

How that connection can impact us

Our bodies have a finite amount of energy that can be used to perform all of our vital functions and desired activity. So, if our brains are working overtime, that might take some of the energy needed to operate our gut.

This might be why you find yourself dealing with some intestinal discomfort right before a public speech or why you forget to eat during exciting or stressful times.

On the other hand, having an unbalanced microbiota may cause your gut to work harder or inefficiently, creating a feeling of stress or other physical symptoms. An imbalance in the microbiota may also signal a hormone imbalance, triggering an emotional response.

“Irritable Bowel Syndrome (IBS) is a great example of this. Patients who suffer from IBS are more likely to experience anxiety and depression than those without GI issues,” says Dr. Craft. “New evidence suggests that the system sends messages to our central nervous system when it’s struggling, causing those mood changes.”

This connection could possibly spell out new treatment options for previously difficult-to-treat digestive system issues, while research continues on the connection between our two “brains.”

Dr. Brandon Craft, M.D., is a board-certified and fellowship-trained gastroenterologist. His clinical interests include general gastroenterology and endoscopic ultrasound. Dr. Craft obtained his medical degree from West Virginia University and completed his residency and a fellowship in gastroenterology and hepatology at the Medical University of South Carolina.

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