Have you ever experienced butterflies in your stomach? Or have your nerves gotten the best of you, and you feel the sudden urge to use the toilet? Well, say hello to your gut-brain connection working in real time! That’s right, your gut can communicate with your brain and vice versa. This connection, called the gut-brain axis, is a complex two-way communication network that allows the brain and the gut to influence each other's functions. Pretty cool, right? Let’s dive into how this connection works and what steps you can take to nurture this gut-brain connection.

What Is the Gut-Brain Axis?

The gut-brain axis (GBA) is a bi-directional or two-way communication pathway between the central nervous system (your brain and spinal cord) and the enteric nervous system (the nervous system of your gut). This pathway connects your mental and emotional states with your intestinal functions. In other words, your gut and brain are talking to each other. 

The enteric nervous system (ENS) shares similar functions to the brain and comes from the same tissue during fetal development. This connection is why your gut is sometimes called your “second brain.” It's also why you might get a gut feeling or have butterflies in anticipation of an event. 

But the GBA is more than just butterflies in your stomach! This connection can have a significant impact on your health. Emerging research reveals that when the GBA is altered our mental health is less supported and risk factors for mental health problems may increase. So, your gut health impacts not only digestion but your mental well-being and more! How is that possible? Next, let’s talk more about how the brain and gut communicate.

Pathways of the Gut-Brain Axis

The GBA involves a complex network of neurons (specialized cells that transmit nerve impulses), hormones (essential chemical substances that serve as messenger molecules in the body), and the immune system. Collectively, this network plays a crucial role in digestion, metabolism, mood, cognition, and mental health. Let’s talk more about these pathways that make this gut-brain connection possible: 

The Vagus Nerve Pathway 

The GBA relies on a nerve network that sends signals between the brain and the gut. The primary link between the brain and the gut is your vagus nerve. This powerful nerve helps manage your mood, immune response, and heart rate. It also controls all food movement through your digestive system, ensuring efficient digestion. 

The vagus nerve and other various neural pathways also transmit sensory information, such as pain or fullness, from the gut to the brain. For example, chemicals in your gut signal to your brain when you're hungry or full. This pathway also transmits motor commands from the brain to the gut to regulate digestive processes. In other words, this network of nerves plays a significant role in your mood, digestion, and appetite.

The Endocrine Pathway 

The endocrine system is made of glands that produce and regulate hormones. It's also another communication highway connecting the brain and the gut. Hormones play a significant role in gut-brain communication. The GI tract produces hormones like serotonin, dopamine, and gut peptides. These hormones can influence mood, appetite, and other aspects of brain function. 

For example, the gut produces about 95% of serotonin in the body. Serotonin, sometimes called the “happiness hormone,” is a neurotransmitter that regulates mood, appetite, and sleep. It plays a crucial role in regulating intestinal movements as well as signaling the state of the gut to the brain. 

Stress, on the other hand, produces cortisol. This stress hormone impacts the endocrine system, disrupting your mood and digestion. Cutting-edge research is seeking to better understand how the microbiome can keep cortisol levels from increasing to reduce anxiety and help ease depressive symptoms. 

The Immune Pathway

Over 70% of your immune system resides in your gut. The bacteria that live there work diligently, responding to toxins, foreign invaders, and pathogens. Stress can also impact the immune system in various ways, including thinning the gut lining. This potentially allows “bad” bacteria or toxins through, activating the immune system. These pathogens may also lead to inflammation and gastrointestinal disorders.

How to Nurture Your Gut-Brain Axis

The connection between your gut and brain is pretty crucial. But what can you do to strengthen that connection? While our understanding of the gut microbiome and the GBA is still in its infancy, there are some diet and lifestyle modifications you can take to help nurture a healthy gut-brain axis. Here are several everyday tips you can easily incorporate for your total health and well-being:

Manage Stress and Stressors

Stress can take a major toll on your health—including the health of your gut! For example, stress exposure can change the composition of your gut microbiome and worsen intestinal inflammation. This can affect GI function and overall well-being. The opposite is also true. An imbalance of your gut microbiota could also trigger inflammatory processes that impact your mood. So if there's an imbalance in stress hormones and inflammation, you could experience impacts not only on your brain, immune, and digestive health but your mental health as well. 

To reduce stress, incorporate diaphragmatic breathing into your daily lifestyle. This deep belly breathing technique engages the parasympathetic nervous system, which drives the “rest and digest” mode. This calms the body and mind while also providing an internal organ massage! Other stress busters include: 

• Listening to calming music
• Connecting with supportive friends for emotional support
• Managing your time effectively by setting realistic goals
• Saying no to requests that don’t support your goals or how you want to live your life! 

Eat a Variety of Plants and Prebiotic Fibers

There are trillions of microbes (or microorganisms) living in your gut. Research suggests that a diversity of microbes plays a key role in regulating brain functions and behavior through the GBA. Your diet hugely impacts what microbes reside in your gut—so what you eat and drink plays a vital role in shaping your gut microbiome. 

Research shows that a diverse plant-rich diet with adequate fiber can help provide a greater diversity of gut microbes. Try adding at least two different-colored fruits and veggies to every meal. Also, try incorporating other fiber-rich food sources such as legumes, nuts, seeds, and whole grains daily. OLIPOP is also an excellent source of prebiotic fiber! 

Prebiotic fiber helps feed the microbes in your gut, producing important metabolites like gases, short-chain fatty acids, and neurotransmitters. These metabolites can stimulate the all-important vagus nerve (that major communication pathway between the gut and brain we discussed earlier!). Unhealthy diets low in fiber and high in fats and sugar can lead to gut dysbiosis, where harmful microbes outnumber beneficial ones. These changes may trigger inflammation in the gut and brain. Carbohydrates, especially dietary fiber, are the most studied nutrients for shaping the gut microbiome.

Move Your Body

Research shows that gentle exercise could positively impact the gut microbiome. It could also help reduce anxiety and depression and improve sleep quality. Ramp up your movement with yoga, biking, or a nature walk.

Prioritize Sleep

Last but certainly not least is sleep! Adequate sleep is vital for mental functioning—and your gut microbiome. Sleep disruption can negatively impact the gut microbiome by reducing the diversity of microbes residing in your gut. This can lead to an imbalance of beneficial and harmful bacteria. Aim for seven to nine hours of shut-eye per night if you can!

The Gut-Brain Axis: The Takeaway

The gut-brain axis is a complex and interconnected system that involves neural, hormonal, microbial, and immune signaling between the gut and the brain. It impacts multiple systems integral in controlling mood, hormones, digestive health, and building a robust immune system. In other words, it plays a critical role in regulating your physical and mental health. 

As we learn more about the role of the gut microbiome and how it impacts health, it is increasingly evident that maintaining a balanced and healthy gut microbiota is essential to your health and well-being. To do that, we suggest a few tips, including managing stress, eating more fiber (OLIPOP can help you meet your daily needs), moving your body, and prioritizing sleep. 

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Meet our Expert This article is written by Kate Scarlata MPH, RDN. Kate Scarlata MPH, RDN is a world-renowned gastroenterology specialized registered dietitian, researcher, writer, and speaker with over three decades of clinical experience. Kate is a New York Times best-selling co-author of 21-Day Tummy Diet and co-author of The Low FODMAP Diet Step by Step, and her latest book is Mind Your Gut, hot off the press in 2024! Kate has made significant contributions to the field of GI nutrition. She is widely regarded for her insightful national and international GI meeting presentations. She resides in Massachusetts with her husband, Russ. Stay in touch with Kate via her website and social channels: www.katescarlata.com Instagram: @katescarlata X: @katescarlata_RD