How your gut microbiome influences your mood
Have you ever noticed your digestion change when you’re stressed or anxious? Or felt “butterflies” before a big event? That’s your gut-brain connection at work which is the powerful two way communication between your digestive system and your mind.
In recent years, research has shown that your gut health plays a direct role in your mood, mental clarity, and emotional balance. This is because the bacteria living in your gut (known as the gut microbiome) influence key brain chemicals like serotonin and GABA, which regulate happiness, calmness, and relaxation.
Understanding the gut-brain axis
The gut–brain axis is the communication pathway linking your digestive system and your central nervous system. It’s how your gut and brain constantly “talk” to each other through nerves (especially the vagus nerve), hormones, and immune signals through the enteric nervous system..
When your gut microbiome is healthy and balanced, it supports positive mood and mental wellbeing. But when the gut is inflamed, sluggish, or imbalanced (a state known as dysbiosis), it can impact your neurotransmitters and lead to symptoms such as:
Anxiety or low mood
Brain fog or fatigue
Poor sleep
Increased stress response
This is why supporting your gut health for mental health is so important.
How gut bacteria supports GABA and serotonin production
Two key neurotransmitters that affect mood, GABA (gamma-aminobutyric acid) and serotonin are heavily influenced by gut bacteria.
Serotonin is your “happy hormone.” Around 90% of serotonin is made in the gut, not the brain. Healthy gut bacteria help produce and regulate serotonin levels, influencing mood, sleep, and overall emotional wellbeing.
GABA is your “calm chemical.” It helps reduce anxiety, improve sleep quality, and promote relaxation. Certain gut bacteria directly help increase GABA activity in the brain.
When your microbiome is balanced, your gut bacteria produce compounds that help your brain stay calm, clear, and positive.
The best bacteria for mood support
Research has identified specific bacterial strains that help regulate mood and support neurotransmitter production:
Lactobacillus rhamnosus: Helps increase GABA receptor expression and may reduce anxiety.
Bifidobacterium longum: Shown to support relaxation and reduce stress hormone (cortisol) levels.
Lactobacillus plantarum: Supports serotonin metabolism and reduces inflammation that can impact mood.
Bifidobacterium breve: May improve mood stability and resilience to stress.
These beneficial microbes are often called psychobiotics probiotics that support both gut and brain health.
Signs your gut health needs support
If you’re struggling with mood swings, anxiety, or fatigue, your gut might be trying to tell you something. Common signs of poor gut health include:
Bloating, constipation, or irregular digestion
Sugar cravings
Low energy and poor concentration
Food sensitivities
Feeling “wired but tired”
Addressing your gut health is a powerful step toward feeling calmer and more balanced emotionally.
How to improve your gut health to support a better mood
You can begin to nourish your gut–brain connection with a few simple daily habits:
Eat fibre-rich foods: Fibre feeds your beneficial bacteria. Include oats, legumes, chia seeds, and a variety of colourful vegetables.
Add fermented foods: Sauerkraut, kimchi, kefir, and coconut yoghurt introduce mood-supporting bacteria.
Manage stress: Chronic stress alters gut bacteria composition. Include calming practices like yoga, deep breathing, and meditation.
Balance your meals: Avoid blood sugar spikes by eating protein and healthy fats with every meal.Support gut lining integrity: Nutrients like zinc, glutamine, and omega-3s help keep your gut barrier strong and reduce inflammation.
Your gut is more than a digestive organ, it’s a key player in your mental and emotional wellbeing. When you nurture your microbiome, you’re not just supporting digestion, you’re cultivating calm, clarity, and joy from within.
Improving your gut health and mood connection doesn’t happen overnight, but small, consistent steps make a huge difference. If you need extra support, book in a consultation today!