Trust Your Gut: What to Know About the Stomach-Brain Connection

A digestive system and brain

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Experts explain how you can change your diet to change your mind.

You’ve felt it before: When you get nervous, your stomach flutters or aches. You’ve been advised to trust this feeling and rely on it, but is your gut actually intuitive? It turns out, there’s evidence to support trusting your gut, literally. Your stomach and brain are directly connected — and can absolutely influence one another.

“Think about a high-pressure situation, like a job interview or on a date: You might experience lightheadedness and weird sensations in your stomach simultaneously,” says Arpana Gupta, Ph.D., co-director of the Goodman-Luskin Microbiome Center at UCLA.

But the connection can cause more than butterflies. If you’ve ever gotten an upset stomach (or worse) in a moment of high anxiety, you’re well aware of this. And it’s not just in your head. 

“If we’re anxious or sad, that affects our digestion,” says Kelly Bender, ND, a licensed naturopathic medical doctor who works with the supplement company bio.me

Since these are notably unpleasant sensations, you might loathe that mysterious link between your mind and your stomach. But the connection between the two body parts is downright amazing — despite sometimes leading to that whole “am I going to vomit?” feeling. You can also use the gut-brain connection to your advantage — and even consume certain foods to keep this tie in tip-top shape.

How are the gut and brain connected?

The link between mental and gastrointestinal health is more multi-faceted than one straight line — it’s called the “gut-brain axis,” Dr. Gupta says. “This is a complex system that shares cyclical, bidirectional communication — or signaling — from the gastrointestinal tract with the central nervous system.”

Your emotions can trigger nausea or bowel movements quickly because “the brain and the gut are in constant communication with one another through multiple pathways, such as the neural, hormonal, metabolite, inflammatory, and vagal signaling,” Dr. Gupta says.

The three most prominent pathways are the vagus nerve, the immune system, and the microbiome.

What is the vagus nerve?

“The main [connection] from the gut to the brain is through the vagus nerve,” Dr. Bender says. (Does that sound familiar? Katie did an interview with an MD that explored everything about this fascinating component of your nervous system.) 

In case you need a refresher, Dr. Gupta breaks it down pretty simply: “The vagus nerve is a two-way superhighway that connects the brain to other parts of the body like the gut. It will ‘sense’ what’s going on in the gut and report back to the brain.” 

Dr. Bender adds, “The vagus nerve is one of a few nerves that’s bidirectional — most nerves only [communicate in] one direction, but the vagus nerve does both.”

But what kind of activity does the nerve sense? “It sends signals about various things going on in the gut — like what bacteria are present or what foods we’ve eaten,” Dr. Gupta says. “Once the brain knows what’s going on in the gut it will send ‘command’ signals to the gut telling it what to do — to digest food we’ve eaten or fight off inflammation, for example.”

How is immunity connected to gut health?

If you’ve ever gotten sick (i.e. if you’re a human being), you’ve probably both cursed your immune system and begged it to work harder. But aside from shielding you from that office cold, your immune system is also in constant communication with your gut. 

“We have a lot of immune cells in the GI tract because technically anything that enters your GI tract is considered material from ‘the outside world,’ and this includes food you consume,” Dr. Bender says. “And because that food is coming from the outside world, your immune system can attack any bacteria or parasites you accidentally eat.”

“The gut contains many immune cells — inflammatory markers — that jump into action at any indication of invasion or trauma by bacteria, pathogens, toxins, or viruses,” Dr. Gupta adds. “When we have problems in the gut, immune cells — cytokines [signaling proteins], for example — will send signals to the brain.”

What about the microbiome?

You’ve probably heard about the microbiome, which Dr. Bender describes as, “the bacteria, parasites, yeast, and other creatures that live in our intestines that aren’t our cells.” 

Dr. Gupta clarifies that these “trillions of tiny microorganisms” basically constitute an environment. And when this delicate environment has too much “bad” bacteria in it, Dr. Gupta says that your mental health can be thrown out of whack: “When the gut is healthy, the microbiome is balanced and thriving and as a result, we have good mental health. When the microbiome is imbalanced, distress signals get sent to the brain that affect mood, cognition, and emotions.” 

But your mind isn’t at the mercy of this relationship; if your gut-brain relationship is unbalanced, you can change those circumstances.

How can you tailor your diet to the gut-brain connection?

“The most influential and easiest way to impact your gut microbiome is through diet,” says Dr. Gupta. “We can support the gut-brain connection by incorporating a balanced and diverse diet rich in fiber, probiotics, omega-3 fatty acids, and antioxidants.” 

“Eating diets rich in diverse fruits and vegetables is the best way to support a healthy gut microbiome,” she continues. But how do you accomplish that, exactly? “If you can get 20-30 different vegetables and fruits per week, you’ll be helping maintain a healthy microbiome.”

Dr. Bender agrees: “Eating a variety of foods is really important. Sometimes, even when we’re trying to be healthy and meal-plan, we eat the same meal five days in a row. That’s not as healthy as variety. The more variation we can have, the healthier our digestion is.”

On the other hand, Dr. Gupta clarifies that avoiding certain foods is as important as embracing variety: “You should minimize consumption of processed foods, added sugars, artificial sweeteners, excessive alcohol, and antibiotics.” 

Dr. Bender agrees that some foods destroy whatever progress you’ve made with your beans-and-greens-packed salads: “When you eat lots of sugar and refined carbohydrates, you’re getting blood sugar spikes throughout the day, which are usually not good for our mental and emotional health.” Dr. Bender says that ultra-processed foods aren’t typically nutrient-dense, which means they’re lacking necessary vitamins and minerals. “If you don’t have those building blocks,” she says, “you’re not going to feel good.”

Which supplements can improve your gut-brain connection?

“Supplements can support the tie between gut and mental health by targeting various aspects of gut health and impacting the gut-brain axis,” Dr. Gupta confirms. “For example, supplements like probiotics and prebiotics help by supplying beneficial bacteria, nourishing the gut microbiome, supporting brain function, and reducing stress and inflammation.”

She notes that most of these supplements haven’t been fully tested, especially in humans. “But at the Goodman Luskin Microbiome Center, we’re performing several ongoing human trials. We’re testing the beneficial effects of patented probiotic and prebiotic blends.” This means there may soon be some pretty cool science to back up the good feelings you get from your daily probiotic routine.

And if you’re interested in dipping your toe into supplements but don’t know where to start, Dr. Bender has good things to say about her partner bio.me. Dr. Bender recommends bio.me’s daily prebiotic fiber and fiber rescue powders. “Bio.me’s fiber products are sources of soluble and insoluble fiber, which are non-irritating,” she says. “The bacteria in your digestive system eat soluble fiber to keep your microbiome happy. And insoluble fiber can improve your bowel movements and help get rid of toxins or other things that can make us feel unwell.”

“There’s also a Synbiotic product,” she adds. “It’s a prebiotic, a probiotic, and a postbiotic. The prebiotic is fiber — food for the bacteria. The probiotic is good bacteria. And then the postbiotic is actually the beneficial stuff that the prebiotic is making. So ingesting postbiotics is a bit of a shortcut.”

It’s clear that carefully balancing your intake of nutrients is key to ensuring that your gut doesn’t disrupt your mental health: “I like to describe the gut microbiome and the brain as best friends. If one is out of whack, the other will follow,” says Dr. Gupta. “They go hand in hand.”