Have you ever felt stomach discomfort when you are feeling nervous, or sudden cravings for certain types of food when you are under emotional distress? This is not a coincidence, as research has shown that the gut and mind are connected. Your body systems work together instead of in isolation. This ‘mind-gut connection’ explains how your gut can affect your mental health, and choosing a diet that improves gut health may also boost mood and mental wellbeing.
How the Gut and Brain Are Connected and Influence Mental Health
First of all, we need to understand what the gut consists of. The gut includes every organ involved in digesting food. It is often called “the second brain” because it is surrounded by nerves that control digestion and nutrient absorption. At the same time, the gut is also able to produce feel-good chemicals that the brain does, including serotonin and dopamine.
Our gut constantly communicates back and forth with our brain. They are connected in two main ways:
- Physical connection: The mind-gut connection is established through the vagus nerve, which originates from the brainstem and extends into the abdomen.
- Chemical connection: The gut and brain “exchange messages” through chemicals such as hormones and neurotransmitters. These chemicals can be affected by the bacteria, viruses, and fungi that live in the gut, making up the gut microbiome.
Today, we know that stress, anxiety, and various negative emotions can cause and worsen digestive conditions such as inflammatory bowel disease, irritable bowel syndrome (IBS), and food sensitivities. Conversely, when your gut is inflamed or its microbiome is out of balance, it produces fewer feel-good chemicals and may contribute to symptoms of depression, anxiety, and schizophrenia.
Common Signs of an Unhealthy Gut
Frequent digestive issues
Gut microbiome imbalances may trigger gastrointestinal issues such as bloating and constipation. Moreover, while some of us may experience occasional diarrhoea due to external factors such as food poisoning, an overly frequent diarrhoea may stem from an overgrowth of harmful bacterial species in the gut.
Persistent fatigue
It is normal to feel unenergised, especially during heavy or busy days. However, persistently low energy levels and fatigue may signal an unhealthy gut. This is because a disrupted gut microbiome may hinder the mitochondria function, which is needed for optimal energy metabolism.
Food intolerance or sensitivities
While some individuals may be intolerant or sensitive to certain foods due to genetics, in some cases, it may also be due to a weakened gut lining. In such cases, the gut’s protective barrier which keeps harmful bacteria and toxins out, may leak, causing problematic substances to trigger inflammatory responses.
Brain fog, mood swings, or anxiety
The mind-gut connection matters for our mental health. Constant, unexplained mood swings, brain fog, depression, anxiety, and other mental health concerns may often be traced back to an imbalance in the gut microbiome.
Sugar cravings and appetite fluctuations
Our gut microbiome may play a key role in the types of food that we crave. While much research is still dedicated to knowing the exact mechanisms, an unhealthy gut may lead to cravings for high-sugar foods or have appetite fluctuations. In turn, beneficial bacteria help stimulate the secretion of gut hormones that regulate appetite and improve insulin sensitivity.
Gut Health Diet Plan
If you suspect that you may have an unhealthy gut and it is affecting your mental health, it is best to consult with a professional nutritionist for a gut health healing plan. This plan may involve more of the following foods to help balance your gut microbiome:
High-fibre foods
Dietary fibre is an essential nutrient for digestive health. There are two forms of dietary fibre needed for a healthy gut, soluble and insoluble fibres. Soluble fibres help feed the gut microbiome, reduce bad or low-density lipoprotein (LDL) cholesterol, and help slow glucose absorption. They can be found in oats, barley, peas, beans, and fruits and vegetables. Meanwhile, insoluble fibres are found in whole wheat and vegetables, and help food pass more quickly through the gut for a smoother bowel movement.
Polyphenols
Polyphenols, found in pomegranate, green tea, berries, and flaxseeds, are potent antioxidants and prebiotics that may help regulate gut microbiomes to improve digestive health. They may promote the growth of beneficial bacteria including Bifidobacteriaceae and Lactobacillaceae, strengthen the gut barrier, and improve nutrient absorption.
Fermented foods
Fermented foods contain beneficial bacteria that restore microbial balance and reduce the population of harmful bacteria. You can get your probiotic intake from yogurt, kefir, sauerkraut, and kimchi.
Resistant starches
Resistant starches are a type of carbohydrate that can reach the large intestines, where they ferment and feed beneficial bacteria. They may also promote a healthier digestion and help slow the absorption of glucose. Resistant starches can be found in oats, legumes, and cooked and cooled potatoes or rice.
Water
Finally, drinking plenty of water as part of your gut health diet plan is essential to stay hydrated. Water helps break down food, supports fibres to function properly, and maintains the gut’s protective lining. Aim to drink 8 glasses of water daily to prevent digestive issues.
Get Qualified Nutritionist Advice to Support Your Mental Health Journey
Recognising the mind-gut connection helps us understand how maintaining gut health is crucial for mental wellbeing. If you are having frequent digestive issues or want to build a healthier relationship with the food you eat, New Leaf nutritionists are here to support you. Our nutritionist in Singapore will provide a gut health diet plan to help address imbalances in your gut, and recommend nutritious foods that may help nourish your body while supporting your mental health. Schedule an appointment today and let us improve your digestive and mental health together.
References
Ataei, P., Kalantari, H., Bodnar, T.S. & Turner, R.J. (2026). The gut–brain connection: microbes’ influence on mental health and psychological disorders. Front. Microbiomes 4:1701608. doi: 10.3389/frmbi.2025.1701608
Calabriso, N., Massaro, M., Scoditti, E., & Carluccio, M. A. (2023). Dietary Polyphenols and Their Role in Gut Health. Nutrients, 15(12), 2650. https://doi.org/10.3390/nu15122650
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
