The Gut–Brain Connection: How Your Digestive Health Affects Your Mental Wellbeing
The idea that our gut influences how we think, feel, and behave is widely understood. It has even found its way into everyday language, we talk about gut feelings, being gutsy, or feeling butterflies in the stomach when we’re nervous.
Yet despite this intuitive understanding, science has only relatively recently begun to unravel how deeply connected the gut and brain really are.
For many people, changes in mood, anxiety levels, or stress tolerance may be closely linked to what’s happening in their digestive system, often without them realising it.
What Is the Gut–Brain Axis?
The gut–brain axis is a complex communication network between the brain and the trillions of microorganisms — bacteria, fungi, and viruses — living in the gastrointestinal tract. Together, these microorganisms form what is known as the gut microbiome.
This system works as a two-way conversation. The brain sends signals to the gut that influence digestion, movement, and immune responses, while the gut sends signals back to the brain that can affect mood, behaviour, and cognitive function.
Research has shown that the composition and diversity of gut microorganisms can have a profound impact on mental health and nervous system function. A healthy, varied diet plays a crucial role in shaping this microbiome by supporting beneficial bacteria and preventing the overgrowth of harmful strains.
Why Gut Health Matters for Mental Wellbeing
When the gut ecosystem is balanced and functioning well, communication along the gut–brain axis remains stable. However, when this system becomes disrupted, a state sometimes referred to as gut dysbiosis, it can affect both physical and mental health.
Emerging research has linked gut dysregulation to a wide range of conditions, including anxiety and depression, as well as neurological conditions such as Parkinson’s disease, Alzheimer’s disease, and multiple sclerosis.
While this area of research is evolving rapidly, the most immediate and commonly experienced effects are often far closer to home — low mood, anxiety, brain fog, fatigue, and reduced resilience to stress.
Healthy Gut, Happier Mind
Many people who experience anxiety are also familiar with digestive symptoms such as:
Abdominal cramps
Nausea
Constipation or diarrhoea
Bloating or discomfort
This overlap is not a coincidence.
The gut contains a large proportion of the body’s serotonin receptors and plays a key role in regulating inflammation and stress hormones. When gut health is compromised, these systems may be affected, influencing how we respond to stress and emotional challenges.
Research suggests that diets rich in fibre, plant diversity, omega-3 fatty acids, and fermented foods may support both gut and mental health. Probiotics and whole foods that nourish beneficial bacteria have been associated with improved stress response and lower risk of anxiety and depressive symptoms.
How Gut Imbalance Can Show Up in Everyday Life
Disruption to the gut–brain axis doesn’t always appear as severe digestive symptoms. It can show up subtly in day-to-day life, such as:
Feeling anxious without a clear trigger
Low tolerance to stress
Poor sleep or early waking
Brain fog or difficulty concentrating
Cravings for sugary or ultra-processed foods
Digestive discomfort that worsens during stressful periods
These signals are often the body’s way of asking for attention, not something to be pushed through or ignored.
Supporting Your Gut to Support Your Mental Health
Small, consistent changes can make a meaningful difference over time. Supporting gut health doesn’t need to be complicated.
You might start by:
Eating a wide variety of plant foods each week to encourage microbial diversity
Including fermented foods if tolerated, such as yoghurt, kefir, or sauerkraut
Prioritising omega-3 rich foods like oily fish, flaxseeds, and walnuts
Eating regular meals to support blood sugar balance
Reducing ultra-processed foods, particularly during periods of stress
Every person’s gut is unique, and what works for one individual may not suit another. Listening to your body is key.
Taking a Moment to Reflect
Today, take a pause. Breathe.
Consider whether your mental health symptoms may have a deeper, physical root.
How is your gut feeling?
Have you been living with digestive symptoms for longer than you’d like to admit?
If you’re curious to learn more, you might consider starting with our free gut health quiz. It takes just a few minutes and can offer valuable insight into your current digestive health, helping you begin to connect the dots between gut and mind.
-
The gut–brain axis is a two-way communication system between your brain and your digestive system, including the gut microbiome. Signals travel in both directions, meaning changes in gut health can influence mood, stress response, and overall nervous system function.
-
Gut symptoms don’t “prove” a cause of anxiety or depression, but research suggests there can be strong links between gut imbalance, inflammation, stress hormones, and how the nervous system functions. Many people notice their anxiety or mood worsens when digestion is unsettled.
-
Many people experience digestive symptoms during periods of stress, including bloating, nausea, constipation, diarrhoea, abdominal cramps, or changes in appetite. This overlap can be a sign the gut–brain axis is under strain.
-
The gut microbiome helps regulate inflammation, immune signalling, and communication with the nervous system. When the microbiome is well-supported, this system can be more stable. When it’s disrupted, some people experience changes in mood, stress tolerance, sleep, or mental clarity.
-
A varied, fibre-rich diet that includes plenty of plant foods can support microbial diversity. Foods containing omega-3 fatty acids and fermented foods (if tolerated) may also help support gut and mental wellbeing over time.
-
Probiotics can be helpful for some people, but responses vary depending on the individual, the strains used, and the underlying gut environment. If anxiety is closely linked with digestive symptoms, targeted support can be more effective than taking a generic supplement.
-
Start small and consistent: increase plant variety, prioritise fibre if tolerated, reduce ultra-processed foods, support blood sugar balance with regular meals, and consider gentle fermented foods. Sleep and stress management also play an important role in gut function.
-
If symptoms are persistent, worsening, or affecting your quality of life, it’s worth speaking to a clinician. Support can be especially helpful if you’re dealing with ongoing digestive symptoms alongside anxiety, low mood, fatigue, or brain fog.
