The phrase "trust your gut" might be more scientific than it sounds. Over the last decade, research has highlighted the gut–brain axis, a bidirectional communication system between your gastrointestinal tract and your central nervous system. The star players? Trillions of microbes that live in your gut, collectively known as the gut microbiome.

The science behind it

Roughly 95% of the body's serotonin, a neurotransmitter critical for mood regulation, is produced in the gut, not the brain (Gershon & Tack, 2007). The microbiome influences serotonin levels, dopamine release, and even gamma-aminobutyric acid (GABA), which helps regulate anxiety.

When your microbiome is balanced, beneficial bacteria support the production of these mood-modulating chemicals. But a diet rich in refined sugars and saturated fats can trigger gut inflammation, linked to depression and anxiety (Foster et al., 2017).

What foods help?

Prebiotics: Foods high in fiber (e.g., legumes, oats, asparagus, bananas) feed beneficial bacteria, leading to increased short-chain fatty acids that support brain health.

Probiotics: Fermented foods like kimchi, kefir, miso, and yogurt have been shown in meta-analyses to reduce depressive symptoms and enhance emotional resilience (Ng et al., 2018).

Polyphenols: Found in berries, cocoa, and green tea, polyphenols act as antioxidants and prebiotics, boosting gut microbial diversity.

Practical takeaway

Every meal is an opportunity to influence your mental health. Adding just one extra serving of vegetables or a fermented food each day has been linked to measurable improvements in mood within weeks (Jacka et al., 2017).

Bottom line: Feeding your microbes means feeding your mind. A diverse, plant-forward diet with fermented foods is a simple but powerful strategy for emotional wellbeing.

References

Foster, J. A., Rinaman, L., & Cryan, J. F. (2017). Stress & the gut-brain axis: Regulation by the microbiome. Neurobiology of Stress, 7, 124–136. https://doi.org/10.1016/j.ynstr.2017.03.001

Gershon, M. D., & Tack, J. (2007). The serotonin signaling system: From basic understanding to drug development. Gastroenterology, 132(1), 397–414. https://doi.org/10.1053/j.gastro.2006.11.002

Jacka, F. N., et al. (2017). A randomized controlled trial of dietary improvement for adults with major depression (the "SMILES" trial). BMC Medicine, 15(1), 23. https://doi.org/10.1186/s12916-017-0791-y

Ng, Q. X., et al. (2018). A systematic review of the role of prebiotics and probiotics in depression. Nutrients, 10(6), 895. https://doi.org/10.3390/nu10070895