The Gut Brain Axis

Wendy Francis, NBC-HWC – Board-Certified Health Coach and Functional Nutritionist

Have you ever had “butterflies” in your stomach before something stressful? Or noticed that when you are anxious, your digestion seems off too? That is not in your head. It is a real example of the gut brain axis at work.

The gut brain axis is the constant communication system between your gut and your brain. These two systems are always sending signals back and forth, influencing how you feel physically, mentally, and emotionally.^[1][2]

This matters more than most people realize because your gut is not just where food is digested. It plays a major role in inflammation, immune function, mood, stress response, and even how clearly you think.^[1][3][4]

So What Exactly Is the Gut Brain Axis?

Think of it as a two way highway between your digestive system and your brain. Your brain can affect your gut, and your gut can affect your brain.^[2][5]

That is why stress can show up as bloating, stomach discomfort, nausea, diarrhea, constipation, or loss of appetite. It is also why poor gut health can sometimes leave you feeling foggy, sluggish, irritable, or just not like yourself.^[2][5]

This communication happens through several pathways, including the nervous system, the immune system, hormones, and the trillions of microbes living in your digestive tract, also known as your gut microbiome.^[1][3][4]

Your Gut Does More Than Digest Food

Many people think of the gut as just the place where food gets broken down, but it does much more than that.

Your gut helps:

• Break down and absorb nutrients
• Support immune health
• Protect against harmful invaders
• Produce important compounds that affect the brain and body
• Influence inflammation and stress signaling

In fact, the gut contains its own vast network of nerves, often referred to as the enteric nervous system. This is one reason the gut is sometimes called the “second brain.” It is not a second brain in the literal sense, but it is deeply wired into how the body functions and how we feel.^[2]

Why the Microbiome Matters

Inside your gut live trillions of bacteria and other microbes. When these microbes are in a healthier balance, they can support digestion, immune function, and overall well being. When that balance gets disrupted, it may contribute to digestive issues, inflammation, and changes in how the body communicates with the brain.^[1][3][4]

Researchers are still learning a great deal about this connection, but what we do know is important. Gut microbes can produce substances and signals that affect the brain, and the brain can also affect the gut environment through stress and nervous system activity.^[1][3][4]

That means what is happening in your gut may influence how you feel, and how you feel may influence what is happening in your gut.

How Stress Affects the Gut

Chronic stress is one of the biggest disruptors of the gut brain axis.

When the body is under constant stress, digestion often takes a back seat. Blood flow, motility, appetite, and gut sensitivity can all shift. Over time, stress may also affect the gut microbiome and increase inflammation, which can make the cycle even worse.^[2][6]

This is why stress management is not just about feeling calmer. It is also about supporting digestion, mood, and long term health.

Simple Signs Your Gut Brain Axis May Need Support

You do not need to overcomplicate this. Sometimes the signs are everyday things people tend to ignore.

• Frequent bloating or digestive discomfort
• Changes in bowel habits
• Brain fog or poor focus
• Feeling wired, anxious, or drained
• Low mood or irritability
• Symptoms that seem worse during stressful periods

These symptoms can have many causes, but they can also reflect the close relationship between gut health, stress, and the brain.

Ways to Support the Gut Brain Axis

The good news is that you do not need an extreme routine to start supporting your gut and brain. Small consistent habits can go a long way.

• Eat more fiber rich foods
  Vegetables, fruits, beans, legumes, nuts, seeds, and whole grains help nourish beneficial gut microbes.^[7]
• Include fermented foods if they work for you
  Foods like yogurt, kefir, kimchi, sauerkraut, and miso may help support the gut microbiome.^[8][9]
• Manage stress on purpose
  Walking, prayer, deep breathing, journaling, quiet time, and mindfulness practices can help calm the stress response and support the brain gut connection.^[5]
• Prioritize sleep
  Sleep and gut health affect each other more than many people realize. A dysregulated body often struggles on both ends.
• Do not chase every supplement trend
  Probiotics may help in some situations, but they are not one size fits all, and the evidence varies depending on the strain and the condition.^[9][10]

The Bottom Line

Your gut and your brain are in constant conversation. When one is out of balance, the other often feels it too.

Supporting the gut brain axis does not mean chasing perfection. It means paying attention to the everyday habits that help your body feel safe, nourished, and resilient. Food matters. Stress matters. Sleep matters. Movement matters. And your gut is listening to all of it.

When you begin to care for your gut, you may be doing far more than helping digestion. You may also be supporting your mood, your energy, your clarity, and your overall wellness from the inside out.