The Gut-Brain Connection: How Your Microbiome Shapes Your Mood

The Gut-Brain Connection: How Your Microbiome Shapes Your Mood

The connection between healthy digestion and mental health has become a hot topic in wellness circles, with mounting evidence suggesting that maintaining a healthy gut microbiome can have a profound impact on mental wellbeing. This relationship is largely driven by the gut-brain axis, a bidirectional communication system that allows the gut and brain to influence each other in ways that affect our mood, cognition and mental health.1-11

The Gut-Brain Axis: Your Gut’s Influence on the Mind

The gut-brain axis refers to the constant communication that occurs between the gastrointestinal tract and the brain. This two-way communication system allows the brain to influence gut function and vice versa.1-5

For example, feelings of stress and anxiety can result in an upset stomach or digestive issues, while an imbalanced gut can lead to mood disturbances, including anxiety and depression.

At the core of this relationship is the microbiome, a complex ecosystem of bacteria, fungi and other microorganisms living in your digestive tract. These microbes help regulate everything from digestion to immune function, but their influence extends far beyond the gut. The microbiome plays a critical role in signalling to the brain, impacting emotions, cognitive functions and overall mental health.1-5

The Microbiome’s Role in Mental Health

A healthy microbiome is often associated with improved emotional regulation, while an imbalanced microbiome has been linked to mental health disorders like anxiety.1-5

Gut bacteria in the microbiome produce neurotransmitters—chemicals like serotonin, dopamine and gamma-aminobutyric acid (GABA)—that influence mood and cognitive processes. Approximately 90% of the “feel good” hormone serotonin is produced in the gut, not the brain.4 This highlights just how significant the gut’s role is in managing mood and emotional states. 

An imbalance in gut bacteria can lead to inflammation and disruptions in these neurotransmitters, potentially causing or exacerbating mental health issues.1-5

How a Healthy Gut Environment Enhances Serotonin Production

A well-balanced gut can enhance the production of serotonin and other neurotransmitters that regulate mood, supporting positive mental health outcomes. To maintain a healthy gut environment, it’s essential to nurture a diverse and balanced microbiome, which is primarily influenced by your diet and lifestyle.1-11

How Diet Impacts Gut Health and Mental Wellbeing

Since the gut microbiome is largely shaped by what you eat, it’s no surprise that diet plays a critical role in mental health.6-11

A diet rich in fibre, prebiotics and probiotics can help nourish beneficial gut bacteria, while a diet high in processed foods, sugars and unhealthy fats can promote an imbalanced microbiome often referred to as dysbiosis.1-5

  • Prebiotics: These are types of fibre that feed the good bacteria in your gut. Foods like onions, garlic, leeks, bananas, apples and whole grains are excellent sources.
  • Probiotics: These are live beneficial bacteria that can be found in fermented foods such as yogurt, kefir, sauerkraut, kimchi and miso. 
  • Polyphenols: Found in foods like dark chocolate, green tea and berries, these compounds act as fuel for good gut bacteria and have been linked to reduced anxiety and depressed mood.
  • Omega-3 fatty acids: Found in fatty fish (e.g. salmon, sardines and herring), flaxseeds and walnuts, omega-3s are anti-inflammatory and can promote a healthy gut-brain connection by reducing inflammation in the gut, which is known to contribute to mental health issues.

Supplements for Gut and Mental Health

In addition to dietary changes, supplements can be an effective way to support both gut and mental health:

  • Probiotic Supplements: These can help maintain or restore balance to the gut microbiome, especially after illness or antibiotic use. Look for high-quality, multi-strain probiotic formulas that contain bacteria known for their mood-boosting benefits, such as Lactobacillus and Bifidobacterium strains.
  • Prebiotic Supplements: If you're not getting enough fibre through your diet, prebiotic fibre supplements can help feed and nourish the good bacteria in your gut.
  • Omega-3 Supplements: If your diet is low in fish or plant-based sources of omega-3s, consider adding a fish oil or flaxseed oil supplement. These provide anti-inflammatory benefits that support brain health.

The Takeaway Message

The relationship between the gut and the brain is complex but crucial for mental health. A healthy gut microbiome is essential for mood regulation, cognitive function and emotional wellbeing. By understanding the importance of the gut-brain axis and nourishing your microbiome through diet and supplements, you can take proactive steps to support both your digestive and mental health.

A diet rich in prebiotic fibre, probiotic foods, omega-3s and polyphenols, combined with targeted supplementation, can help you maintain a healthy gut and, as a result, a more balanced mind.

Read more about diet and lifestyle strategies and interventions for mental health in another article - Healthy Diet, Healthy Mind: The Role of Nutrition in Mental Health.

Always consult with a healthcare professional before starting any new supplement regimen to ensure it’s right for you.

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This article was written by Stephanie Berglin, Nutritionist and Herbalist. 

 

References:

  1. Clapp M, et al. Gut microbiota's effect on mental health: The gut-brain axis. Clin Pract 2017;7(4):987.
  2. Xiong RG, et al. The role of gut microbiota in anxiety, depression, and other mental disorders as well as the protective effects of dietary components. Nutrients 2023;15(14):3258.
  3. Wilson DR, et al. The gut microbiome and mental health. J Holist Nurs 2024;42(1):79-87.
  4. Martin SE, et al. The role of diet on the gut microbiome, mood and happiness. medRxiv [Preprint] 2023:2023.03.18.23287442.
  5. Limbana T, et al. Gut microbiome and depression: How microbes affect the way we think. Cureus 2020;12(8):e9966. 
  6. Suárez-López LM, et al. Influence of nutrition on mental health: Scoping review. Healthcare (Basel) 2023;11(15):2183.
  7. Grajek M, et al. Nutrition and mental health: A review of current knowledge about the impact of diet on mental health. Front Nutr 2022;9:943998.
  8. Bremner JD, et al. Diet, stress and mental health. Nutrients 2020;12(8):2428.
  9. Loughman A, et al. Diet and mental health. Mod Trends Psychiatry 2021;32:100-112.
  10. Muscaritoli M. The impact of nutrients on mental health and well-being: Insights from the literature. Front Nutr 2021;8:656290.
  11. Firth J, et al. Food and mood: How do diet and nutrition affect mental wellbeing? BMJ 2020;369:m2382.

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