When we think about looking after our mental health, we often focus on strategies like staying connected with others, exercising regularly, practising mindfulness, or building in time for self-care. These are all important — but there’s another piece of the puzzle that’s often overlooked: your gut health.
Emerging research continues to show that the health of your gut microbiome — the trillions of microbes living in your digestive system — plays a meaningful role in how you feel, think, and function day to day.
The Gut–Brain Connection
Your gut and brain are in constant communication. This connection is often referred to as the gut–brain axis.
Microbes in your gut send signals to your brain through:
- The vagus nerve, a direct communication pathway between the gut and brain
- The enteric nervous system, sometimes called the “second brain,” which helps regulate digestion and communicates with your central nervous system
This means what’s happening in your gut doesn’t stay in your gut — it can influence your mood, stress levels, and overall mental wellbeing.
Gut Health and “Feel Good” Chemicals
Your gut plays a key role in producing important neurotransmitters:
- Around 90% of serotonin (often called the “feel good” chemical) is produced in the gut
- Approximately 50% of dopamine, which influences motivation, focus, and decision-making, is also produced there
The balance of bacteria in your gut can influence how much of these chemicals are produced and how effectively they function. When your gut microbiome is well supported, it can help promote a more stable and positive mood.
Feeding Your Gut: Why Prebiotic Fibre Matters
To keep beneficial gut bacteria healthy, they need the right fuel — and this comes from prebiotic fibre.
Prebiotic fibres are found in plant-based foods such as:
- Wholegrains
- Fruits and vegetables
- Legumes and beans
- Nuts and seeds
These fibres act as food for your beneficial gut bacteria, helping them grow and thrive.
A practical and achievable goal is to aim for around 30 different plant foods per week. This doesn’t mean 30 large portions — even small amounts count. Variety is key, as different plant foods support different types of beneficial bacteria.
The Role of Probiotic Foods
In addition to feeding your existing gut bacteria, you can also introduce beneficial bacteria through probiotic foods.
Probiotics are defined as live microorganisms that, when consumed in adequate amounts, provide a health benefit.
Foods that naturally contain probiotics include:
- Yoghurt with live cultures
- Kefir
- Sauerkraut
- Kimchi
- Miso
- Tempeh
Including these foods regularly can help support a diverse and balanced gut microbiome.
What Does the Research Say?
A recent Australian study explored how diet influences mental health through the gut.
In this randomised controlled trial, 119 adults with moderate psychological stress were assigned to one of four groups for eight weeks:
- Usual diet (no changes)
- Probiotic supplement only
- High prebiotic fibre diet
- Combined high prebiotic diet and probiotic supplement
Researchers measured outcomes using a tool called Total Mood Disturbance, along with levels of anxiety, stress, sleep, and overall wellbeing.
The results were clear:
- The high prebiotic fibre diet group showed the most meaningful improvements in mood
- Probiotic-only and combined groups showed smaller improvements
- A diet rich in prebiotic fibre was linked to improvements in mood, stress, anxiety, and sleep
This highlights that while probiotics can help, what you consistently eat — particularly fibre-rich plant foods — plays a central role.
Practical Ways to Support Your Gut and Mind
You don’t need to overhaul your diet overnight. Small, consistent changes can make a real difference:
- Add fruit or nuts to your breakfast
- Include vegetables at both lunch and dinner
- Swap to wholegrain versions of bread, pasta, and rice
- Add legumes (like lentils or chickpeas) to meals
- Include yoghurt or fermented foods regularly
- Aim to gradually increase variety across the week
Take Home Message
Your mental health is influenced by many factors — and your gut health is one of them.
By regularly including a variety of fibre-rich plant foods and probiotic sources, you can support your gut microbiome, which in turn may help improve mood, stress levels, and overall wellbeing.
It doesn’t need to be perfect — just consistent.
Need Support?
If you’d like help improving your gut health and building a realistic, personalised approach to nutrition, Feed Your Future Dietetics can support you.
With over 10 years of experience, we help individuals create simple, sustainable strategies that support both physical and mental wellbeing.
Get in touch today:
ashleigh@feedyourfuturedietetics.com
References
Hill C, Guarner F, Reid G, et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol. 2014;11:506–514.
Freijy TM, Cribb L, Oliver G, et al. Effects of a high-prebiotic diet versus probiotic supplements versus synbiotics on adult mental health: The “Gut Feelings” randomised controlled trial. Front Neurosci. 2023;16:1097278.
