Anxiety and the Gut: Why Your Digestion Could Be Driving Your Mood.

It’s common to treat health concerns as though they exist in separate boxes: constipation goes in one, anxiety in another, fatigue in a third. But in reality, the body rarely works that way. These seemingly unrelated problems often share a single root cause, and more often than not, that underlying cause is in the gut.

How the Gut and Brain Communicate

The digestive system is more than a place to process food. It’s closely tied to your immune system, hormone regulation, and even the production of neurotransmitters (the chemical messengers that shape how you feel day to day). This is known as the gut–brain axis, a communication network that runs both ways.

Messages travel:

• through the vagus nerve, sending signals between your gut and brain,

• via the immune system, with inflammation in the gut influencing brain chemistry,

• through the endocrine system, where gut microbes help regulate cortisol and other stress hormones,

• and by metabolic messengers, such as short-chain fatty acids, which affect inflammation and the brain’s protective barrier. When this system falls out of balance, the effects ripple outward; not just into digestion, but into mood, stress tolerance, and mental well-being.

Microbiome and Mood

Your gut houses trillions of microorganisms, and they directly influence mental

health:

• Certain strains of bacteria can help produce calming neurotransmitters like GABA.

• Around 90% of serotonin - often called the “happy hormone” - is made in the gut.

• Dysbiosis (an imbalance in gut bacteria) is linked with changes in dopamine and glutamate, both tied to anxiety and mood regulation. When the microbiome isn’t thriving, the nervous system tends to struggle too.

The Role of Minerals and Energy:

Alongside gut health, minerals are another overlooked piece of the puzzle. Magnesium, sodium, potassium, and iron drive hundreds of processes in the body; from muscle contractions (including the gut muscles that move food along) to nervous system regulation and mitochondrial energy production.

Depletion can show up as:

• Constipation occurs when magnesium is low or bile flow is sluggish.

• Anxiety occurs when sodium–potassium balance is disrupted.

• Fatigue when the mitochondria can’t generate energy efficiently.

Stress, processed food, poor sleep, overexercise, and certain medications can all drain these reserves, leaving the gut, mood, and energy production struggling at the same time.

Stress, Leaky Gut, and the Anxiety Cycle:

Chronic stress doesn’t just affect your headspace; it changes your gut, too. When the intestinal lining becomes “leaky”, inflammatory molecules enter the bloodstream and trigger systemic reactions that reach the brain. This disrupts neurotransmitter balance and creates a cycle: poor gut health fuels anxiety, while anxiety worsens gut dysfunction.

What the Research Shows:

• IBS sufferers experience anxiety and depression at significantly higher rates, pointing to shared pathways.

• Probiotic trials show certain strains can improve stress resilience and reduce anxiety.

• Mineral deficiencies, particularly magnesium, are tied to both constipation and nervous system dysregulation.

• Diets rich in fibre and plant diversity support a healthier microbiome and better mood stability.

Moving Beyond Symptom Fixes: It’s easy to assume constipation just needs more fibre, or anxiety just needs therapy. But unless the underlying foundation is addressed (your digestive system, microbiome balance, and minerals), improvements are usually short-lived.

Building a Stronger Foundation: Lasting progress comes from rebuilding the systems that keep everything connected.

This means:

1. Reducing stress load so your nervous system can regulate and absorb nutrients more effectively.

2. Somatic healing to facilitate the healing of pain and stress.

 3. Restoring minerals with whole foods and personalised supplementation.

4. Balancing the gut microbiome by calming inflammation, clearing nasty pathogenic bacteria, and improving levels of beneficial bacteria instead, and improving motility.

5. Using functional testing - such as microbiome analysis, mineral testing, or stool panels - to identify hidden imbalances.

Anxiety, constipation, fatigue - these aren’t random, separate issues. They are signals pointing back to the gut and the systems connected to it. Supporting digestive health can often calm the nervous system, improve energy, and ease mood challenges at the same time.

At The Naturopathic Co., we use advanced microbiome testing and other functional assessments to uncover what’s really happening beneath the surface. With this knowledge, we create tailored, evidence-based plans that go beyond band-aid solutions - supporting gut function, mental wellbeing, and whole-body balance. Yvette is a qualified Naturopath and Nutritionist, MINDD Practitioner, and member of the Naturopaths and Herbalists Association of Australia.

Yvette is the founder of The Naturopathic Co., a leading naturopathy clinic recognised for its evidence-based approach and personalised care. Yvette specialises in the treatment of gut health and digestive complaints, skin issues, mood disorders, hormonal concerns, weight, fatigue, and more. Yvette consults with patients Australia-wide.