Mood and Microbes: The Gut-Brain Connection Explained

Ever binge-eaten a pack of chips or cookies before an exam out of stress?

Or

bought chocolates for someone feeling low, someone you wanted to apologize to, or someone with whom you wanted to share good news?

Or

felt butterflies in your stomach when seeing a loved one?

I’m sure all of us have experienced at least one of these moments. But have you ever wondered where these actions stem from?

We engage in these behaviors so often that they feel like natural reflexes. So, let’s take a moment to understand the science behind them.

The Science Behind the Gut-Brain Connection

The brain and gut are in continuous communication via a sophisticated system of nerves, hormones, immune signals, and metabolic pathways, influencing everything from mood and cognitive function to digestion and immunity. This two-way connection, referred to as the gut-brain axis, is why stress impacts digestion and why imbalances in the gut have an effect on mental well-being.

One of the most important communication channels is the vagus nerve, a direct neural link that functions like a superhighway, transmitting messages from the gut to the brain. The enteric nervous system (ENS), sometimes referred to as the "second brain," contains more than 500 million neurons which works alongside with it to control gut functions independently.

The gut microbiome trillions of microbes that live in the intestines is also important in controlling mood, emotions, and brain function. These microbes produce neurotransmitters such as serotonin, dopamine, and GABA, which influences happiness, stress, and relaxation. In fact, around 90% of serotonin, the “feel-good” chemical, is produced in the gut.

The gut microbiota also releases short-chain fatty acids (SCFAs), which helps regulate inflammation and brain function. When the microbiome is imbalanced (dysbiosis), it can lead to increased intestinal permeability ("leaky gut"), allowing toxins to enter the bloodstream and trigger inflammation, which has been linked to anxiety, depression, and neurodegenerative diseases.

No wonder why they say, 'The way to a man’s heart is through his stomach because a healthy gut doesn’t just nourish the body, it nurtures the mind and soul too!

Functions and Conditions Influenced by the Gut-Brain Axis

In addition to its effects on digestion, metabolism, mood, immunity, and cognitive function, the gut-brain axis also influences food cravings, stress regulation, pain sensitivity, and gut motility. It helps control hunger signals, food intolerances, and inflammation, while also influencing conditions like irritable bowel syndrome (IBS), anxiety, depression, and chronic fatigue. Neuro-developmental disorders such as autism, neurodegenerative diseases like Parkinson's, and autoimmune conditions like multiple sclerosis have all been linked to disruptions in this connection. We can better manage mental and gut health by understanding and fostering this connection.

Ways to Support a Healthy Gut-Brain Axis

Taking care of our gut health can have a profound impact on our mental well-being, and vice versa. It is advisable to consume a diverse, plant-rich diet with fiber, probiotics, and antioxidants which helps nourish good gut bacteria. Since stress plays a major role in gut-brain health, managing stress is equally important which can be done by incorporating techniques like meditation, deep breathing, and relaxation therapy in our day-to-day lifestyles.

Healthcare providers also explore treatments like probiotics, antibiotics, and fecal transplants for restoring microbial balance in certain disorders. Cognitive Behavioral Therapy (CBT) and relaxation therapy may help manage stress-related digestive issues. By combining a healthy diet, stress management, and gut-friendly therapies, we can strengthen the gut-brain connection and improve overall health.

"The road to better mental and physical health begins in our gut.

Nurture it, and watch everything fall into place!"

References:

1. Gwak, M.-G., & Chang, S.-Y. (2021). Gut-Brain Connection: Microbiome, Gut Barrier, and Environmental Sensors. Immune Network, 21(3), e20. https://doi.org/10.4110/in.2021.21.e20

2. Appleton, J. (2018). The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integrative Medicine (Encinitas), 17(4), 28–32. PMCID: PMC6469458, PMID: 31043907.

3. Cleveland Clinic. (n.d.). The gut-brain connection. Retrieved from https://my.clevelandclinic.org/health/body/the-gut-brain-connection