Gut-Brain Connection: How Digestive Health Affects Mood

Estimated Reading Time: 6 minutes

Published on: 23 Jul 2025

Have you been feeling down or stressed lately, sometimes for no clear reason? Science shows there may be a surprising reason for this: your gut and brain are closely connected, and your digestive health can affect your mental well-being.

Your gut and brain constantly communicate through the gut-brain axis, influencing how you think, feel, and focus. An unhealthy gut can lead to brain fog, mood swings, or anxiety, while a healthy one supports calmness and clarity. Diet, sleep, and stress levels all impact this connection.

So, let's explore how caring for your gut can boost your mental well-being.

But first, let’s understand what the gut-brain axis is.

What Is the Gut-Brain Axis?

The gut-brain axis is the system that links the gut and brain. This connection allows them to send messages back and forth, like a phone call.

This communication mainly occurs through a special nerve called the vagus nerve, which runs from your brain to your stomach and intestines.

But that’s not the only way they talk. Hormones, immune cells, and other messengers also carry signals between the two.

Your emotions can affect how your gut works. For example, you may feel sick to your stomach when you’re nervous or get a stomachache when you’re stressed. But it also works in the other direction, when your gut is out of balance, it can affect your emotions and thinking.

That’s why gut health is so important; not just for your digestion, but for your overall mood, focus, and even how you handle stress.

So, now the question is: how is it connected to mental health, and what is the “second brain”?

Also Read: 15 Natural Ways to Lower Your Stress Hormone Aka Cortisol Levels!

Your “Second Brain”

Scientists often refer to the gut as the “Second Brain” because it contains more than 100 million nerve cells, more than the spinal cord.

This second brain controls digestion and also plays a role in your mood and brain function. One Your gut helps produce important chemicals called neurotransmitters, Such as serotonin, often referred to as the “Happy Chemical.” It helps control mood, sleep, and feelings of well-being.

Surprisingly, about 90% of serotonin is made in the gut. That’s right; most of the chemicals that help you feel happy come from your digestive system!

Gut Microbiota and Mental Health

Your gut is home to trillions of tiny living organisms. These include bacteria, viruses, fungi, and other microbes. Together, they’re called your gut microbiota or gut flora.

These microbes aren’t bad; in fact, many of them are helpful. They break down food, help you absorb nutrients, and protect you from harmful bacteria. They also produce chemicals that affect your brain.

When the balance of these microbes is right, your gut feels healthy. But when things get out of balance (a condition called dysbiosis), you may notice problems like gas, bloating, poor digestion, and mental health issues like mood swings, anxiety, or depression.

Some reviews have highlighted that people with depression or anxiety often have an unhealthy mix of gut bacteria. While more research is needed, it’s clear that your gut microbes play a big role in your mental health.

Now that you understand the importance of a healthy gut-mental health connection, it’s time to adjust your lifestyle accordingly. Let’s explore foods to include and lifestyle changes you can adopt.

How You Can Support & Repair Your Gut-Brain Connection

What you eat, how much you move, how well you sleep, and how you deal with stress; all of these things affect your gut and your brain.

Here are a few simple ways to support your gut-brain connection:

1. Eat More Fiber

Foods high in fiber help feed the good bacteria in your gut. Examples include:

Whole grains (like brown rice and oats)

Beans and lentils

Fruits (like apples and bananas)

Vegetables (like spinach, broccoli, and carrots)

Fiber helps your good gut bacteria grow and stay strong.

2. Add Prebiotics

Prebiotics are special types of fiber that feed your good gut bacteria. Foods with prebiotics include:

Garlic

Onions

Asparagus

Leeks

Bananas

Adding these to your diet can help build a healthier gut.

3. Eat Fermented Foods

Fermented foods contain probiotics, which are live good bacteria that can help improve your gut health. Try eating:

Yogurt with live cultures

Kefir (a drink similar to yogurt)

Sauerkraut (fermented raw cabbage preserved from salt)

Kimchi (salted and fermented vegetables)

Miso (fermented soybeans)

These foods help add helpful bacteria to your gut, which may support better mood and brain function.

4. Cut Back on Sugar & Processed Foods

Eating too much sugar and ultra-processed foods, such as chips, cookies, and fast food, can harm your gut bacteria and increase inflammation in the body. Try to eat these foods less often.

5. Stay Active

Exercise helps keep your gut healthy and your mood balanced. Aim for at least 30 minutes of movement most days of the week.

6. Sleep Well

Sleep gives your gut time to rest and reset. Poor sleep can upset the gut-brain balance and lead to stress and poor focus.

7. Manage Stress

Too much stress can harm your gut. Deep breathing, yoga, journaling, or spending time in nature can help you relax.

Also Read: Stress Relief Vitamins: Who Should Take Vitamins for Stress Relief?

Now, let's move ahead and learn what psychobiotics are and what they do for your mental health.

Psychobiotics: Probiotics for Mental Health

Psychobiotics are a special kind of probiotic that may help improve mental health. Some types of bacteria, such as Lactobacillus and Bifidobacterium, are being studied for their ability to support mood and reduce anxiety.

Early research suggests that these psychobiotics may help people feel better by improving the way their gut communicates with their brain. Scientists are still learning about how they work, but these probiotics may one day become part of mental health treatments.

Future Research and Considerations

Researchers are now looking at how gut health may be linked to conditions like:

Autism

Alzheimer’s disease

Parkinson’s disease

Some studies suggest that changes in gut bacteria could play a role in these conditions. However, more research is needed to understand how this works.

It's essential to consult your doctor before making significant changes to your diet or taking new supplements. Medications, stress, sleep, and even where you live can affect your gut health, too.

Also Read: When is the Best Time to Take Fiber Supplements for Better Health Benefits?

Conclusion: A Healthy Gut = A Happier Mind

Your digestive system and brain are deeply connected. Taking care of your gut can help you feel better both physically and mentally.

Here’s a quick recap:

Eat fiber-rich and fermented foods.

Add prebiotics to your meals.

Avoid too much sugar and processed foods.

Get regular exercise, good sleep, and manage stress.

Consider probiotics and psychobiotics if your doctor recommends them.

When your gut is healthy, your brain functions better; you think more clearly, feel calmer, and experience a more stable mood. Even small diet changes, like adding natural gut-supporting ingredients, and lifestyle tweaks can make a big difference over time.

Disclaimer: This article is for educational purposes only. It is not a replacement for medical advice. Always talk to your doctor or a healthcare professional if you have health concerns or before starting a new treatment.

References

Miri, S. et al. (2025) Neuromicrobiology, an emerging neurometabolic facet of the gut microbiome?, Frontiers. Available at: https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1098412/full#:~:text=It%20is%20estimated%20that%2090%E2%80%9395%25%20of%20the%20body%E2%80%99s%20serotonin%20is%20located%20within%20the%20gastrointestinal%20tract.%20The%20gut%20microbiome%20produces%20a%20significant%20amount%20of%20serotonin (Accessed: 21 April 2025).

(No date a) Gut microbiota and its metabolites in depression: From pathogenesis to treatment - ebiomedicine. Available at: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(23)00092-0/fulltext (Accessed: 21 April 2025).