Did you know the food we eat has a direct impact on how we feel? When we consume food, it travels in our digestive system from our mouth, to stomach, to the small intestine where our food is digested, and nutrients are absorbed. This small intestine, also known as our gut, is filled with over 100 trillion micro-organisms, known as our gut microbiome¹. Up until recent times, this gut microbiome was relatively undiscovered. However, in recent decades, new research has begun helping us understand the crucial role our gut bacteria play in our mood and mental wellbeing.
What is the gut-brain axis, and why this is important
Scientists in the field of nutritional psychiatry and gut health now have a better understanding of how our gut microbiome regulates and impacts our emotions. Studies examining the type of bacteria in our gut have revealed a diverse range of gut bacteria influences our brain, through the gut-brain axis¹.
Research has found our gut can impact our brain through both direct and indirect pathways. Our gut bacteria play a role in the production of neurotransmitters such as serotonin that are important for our mood².
The foods we eat can also impact the growth of our brain cells. A study of nutrient-rich diets of fruits, vegetables, nuts, probiotic- and fibre-rich foods; versus diets of ultra-processed food, found an ultra-processed diet was associated with a smaller hippocampus—the part of our brain responsible for cognition and learning, as well as mood³.
Supporting a diverse gut microbiome can also help lower levels of inflammation in the body. As inflammation can contribute to the development of some mental health conditions, such as depression⁴, eating a gut-healthy diet is key to feeling good.
Food and mood
One of the best foods we can eat for our mood is vegetables. Vegetables are loaded with gut-friendly nutrients including fibre. Fibre is important as it is broken into short-chain fatty acids (SCFAs) that help lower inflammation in the body¹. Fibre is found predominantly in the skins of vegetables, as well as in high amounts in cold starchy vegetables, such as cold, cooked potato or sweet potato (potato salad anyone?) ¹.
Vegetables are also packed with prebiotics such as fructans, galacto-oligosaccharides and resistant starches⁵. Prebiotic foods are those foods that feed the gut bacteria. Supporting your gut microbiome with a wide range of prebiotic-rich vegetables supports the growth and diversification of your gut microbiome⁵. Vegetables rich in prebiotics include beans, cruciferous vegetables, such as brussels sprouts, cabbage, or cauliflower, as well as peas, asparagus, artichokes and potato⁵.
The easiest way to support your gut health is to aim to eat vegetables at each mealtime. Go for half a plate of vegetables at main meals and fill your snack times with vegetables you have on hand.
Acknowledgement to Nutrition Australia for this content.
References
[1] Young, C. (2021). Diet and the Gut Microbiota. The Food and Mood Centre.
[2] O’Mahony, Clarke, G., Borre, Y. ., Dinan, T. ., & Cryan, J. . (2015). Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behavioural Brain Research, 277, 32–48.
[3] Jacka, F., Cherbuin, N., Anstey, K. J., Sachdev, P., & Butterworth, P. (2015). Western diet is associated with a smaller hippocampus: a longitudinal investigation. BMC Medicine, 13(1), 215–215.
[4] Marx, W., Lane, M., Hockey, M., Aslam, H., Berk, M., Walder, K., Borsini, A., Firth, J., Pariante, C. M., Berding, K., Cryan, J. F., Clarke, G., Craig, J. M., Su, K.-P., Mischoulon, D., Gomez-Pinilla, F., Foster, J. A., Cani, P. D., Thuret, S., … Jacka, F. N. (2021). Diet and depression: exploring the biological mechanisms of action. Molecular Psychiatry, 26(1), 134–150.
[5] Dietitians Connection. Prebiotics and Gut Health.
