Healthy Digestion, Healthy You

The Brain-Gut Connection

Ever had “butterflies in your stomach”? How about a “gut instinct”? Maybe a “gut-wrenching experience”? When a “gut check” tells you how you feel, it’s tempting to think that it’s all in your head. But the truth is, when instincts tell you to “go with your gut”, your gut really is trying to tell you something.

There really is a strong connection between your brain and your digestive tract, and they are in constant communication with one another. An incredible amount of information travels between your gut and your brain – so much so, that the nervous system that resides in your digestive tract is often called the body’s “second brain”.

Your Body’s Two Brains

The connection between your brain and your “second brain” in your digestive tract is something you’ve probably experienced in the form of a “gut reaction”. You know the feeling when you get some bad news, or have a difficult conversation with someone. Your gut tells you exactly how you’re feeling. When stress or anxiety strikes, your brain sends a signal to your gut – and the next thing you know, you’ve got a churning stomach.

The signals travel in the other direction, too – from gut to brain. This system alerts the “first brain” if you’ve eaten something you shouldn’t have, and also keeps tabs on your hunger level and your mood. When something in your digestive system isn’t quite right, an alert is sent to your brain – often before you even notice that anything is wrong.

Your Gut and Your Mood

It’s clear that certain emotions can trigger a digestive response, but there is also speculation that the reverse may also be true – conditions in your gut may influence how you feel.

Studies in mice have suggested that introducing certain strains of bacteria into the digestive tract (specifically, two called lactobacillus and bifidobacterium) can reduce “anxiety-like” behavior in the mice.[i]

The thinking is that these two strains of bacteria (commonly found in yogurt) alter the bacterial makeup in the gut in such a way that there is an effect on brain chemistry – perhaps by stimulating the production of certain brain chemicals (called neurotransmitters) that play a key role in determining mood.

Whether the same holds true for humans is yet to be seen, but there is no question that your brain and gut are well connected – so it makes sense that keeping your digestive system in tip-top shape is vital to your sense of well-being.

The steps you take to keep yourself healthy are the same ones that promote digestive health, too. A diet that includes plenty of fiber from colorful fruits and vegetables and whole grains, adequate hydration, a source of probiotics and regular exercise are all key factors. Fibers help promote regularity (which could affect your mood!), and certain fibers also promote the growth of the “good” bacteria in your microbiome.

Taking time to enjoy your meals helps, too. When you slow down you may eat less food, and you’ll probably be less stressed – which means you’ll be sending signals to ‘both’ your brains. When you eat more slowly, it allows time for your gut to tell your brain that you’re full – and for your brain to tell you that you’re more relaxed, too.

[i] Dinan TG, Cryan JF. Neurogastroenterol Motil. 2013; 25(9):713-9.

Susan Bowerman, M.S., RD, CSSD, CSOWM, FAND –Sr.Director, Worldwide Nutrition Education and Training

Susan BowermanM.S., RD, CSSD, CSOWM, FAND – Sr. Director, Worldwide Nutrition Education and Training

Susan Bowerman earned a B.S. in biology with distinction from the University of Colorado, and received her M.S. in food science and nutrition from Colorado State University. She is a registered dietitian, holds two board certifications from the Academy of Nutrition and Dietetics as a certified specialist in sports dietetics, and a certified specialist in obesity and weight management, and is a Fellow of the Academy.