The Science Behind the Gut-Brain Connection 🧠

Fact-Checked By a Nutritionist MD

Published on June 27, 2025

You’re not imagining it — the way your gut feels really can affect the way your brain functions.

That sudden brain fog after lunch? The anxious flutter in your stomach before a big meeting? The low mood that lingers despite “doing everything right”?

It’s all connected through what scientists now call the gut-brain axis — a two-way communication highway between your gut and your brain that influences mood, memory, digestion, immunity, and even long-term mental health.

🔬 What Is the Gut-Brain Axis?

The gut-brain axis (GBA) is a complex communication network that links the central nervous system (your brain and spinal cord) with the enteric nervous system (your gut’s independent nervous system). This system includes:

The vagus nerve — your body’s primary gut-brain messenger

Neurotransmitters like serotonin, dopamine, and GABA, produced in the gut

The immune system, which connects gut health to systemic inflammation and brain function

Metabolites like short-chain fatty acids (SCFAs), which influence brain chemistry and barrier protection

The gut is sometimes called the “second brain” — and for good reason: over 90% of serotonin and 50% of dopamine are made there, not in the brain.

🧬 Why the Microbiome Matters

Your gut houses trillions of microorganisms — collectively known as the microbiome — that play an essential role in regulating:

Neurotransmitter production (mood and motivation)

Immune signalling and inflammatory response

Nutrient absorption and metabolism

Blood-brain barrier integrity (protecting the brain from harmful compounds)

When the microbiome is healthy and diverse, your gut and brain communicate smoothly. But when it’s out of balance — due to stress, antibiotics, poor diet, or processed food — the consequences are wide-reaching.

🧠 Symptoms of a Disrupted Gut-Brain Axis

A compromised gut-brain axis doesn’t just cause bloating or discomfort — it may show up as:

- Brain fog or difficulty focusing

- Anxiety, low mood, or irritability

- Trouble sleeping or staying asleep

- Cravings or poor blood sugar regulation

- Fatigue that lingers despite rest

- Inflammation or immune imbalances

🧪 How to Support a Healthy Gut-Brain Axis (Based on Research)

1. Eat for Microbial Diversity

Aim for 30+ different plant foods per week to feed a healthy gut microbiome. Include:

- Fibre-rich vegetables and whole grains

- Polyphenol-rich foods like berries, dark chocolate, and olive oil

- Prebiotic foods (onion, garlic, leek, oats, bananas)

2. Supplement with Probiotics and Prebiotics

Certain strains like Lactobacillus rhamnosus and Bifidobacterium bifidum have been linked to:

Reduced cortisol levels

Better emotional regulation

Improved cognitive flexibility

Pair these with prebiotic fibres like inulin or acacia fibre to help them thrive.

3. Support Your Stress Response with Adaptogens

Stress affects gut motility, inflammation, and permeability. Adaptogenic herbs like:

Ashwagandha

Rhodiola rosea

Panax ginseng

Adaptogens help regulate your HPA (hypothalamic-pituitary-adrenal) axis and keep the gut-brain axis stable.

4. Boost Digestive Efficiency with Enzymes

Without proper breakdown, even nutritious foods go to waste. Enzymes like these are vital to getting all the nutrients from your food:

Amylase (carbs)

Protease (proteins)

Lipase (fats)

To ensure your gut can access the nutrients your brain depends on, regularly consume digestive enzymes and over enough time and consistency, you will feel much different.

Supporting the gut-brain axis is hard - here's how to make it easy

If you’re looking for a daily routine that supports the gut-brain axis without needing 10 different supplements, GRNS was formulated with exactly that in mind. One scoop contains:

- A diverse blend of fermented greens and fruits

- 5 gut-supportive probiotic strains

- Inulin, acacia fibre, and digestive enzymes

- Adaptogens like Rhodiola, ashwagandha, and Panax ginseng

- Lion’s Mane mushroom and blueberry extract to support memory and mental performance

It’s a simple, evidence-informed way to give your gut and brain what they need — and show up sharper, calmer, and more energised every day.

A girl drinking greens powder from her glass in the garden

🌿 FAQ: The Gut-Brain Axis

Q: What is the gut-brain axis in simple terms?
The gut-brain axis is the communication network between your gut and brain. It involves nerves (especially the vagus nerve), hormones, and your gut microbiome. This system lets your brain influence digestion and mood — and lets your gut influence how you feel, think, and respond to stress.

Q: How does the gut affect mental health?
The gut produces around 90% of serotonin (a mood-regulating neurotransmitter) and helps regulate other brain chemicals like dopamine and GABA. An unhealthy gut can increase inflammation and disrupt neurotransmitter balance, which may contribute to anxiety, depression, or brain fog.

Q. Can fixing my gut improve my focus and mood?
Yes. Supporting your gut through diet, probiotics, prebiotics, and stress management may help improve mental clarity, emotional regulation, and resilience. Many people report improvements in energy, focus, and mood after addressing gut imbalances.

Q: What makes GRNS different from other greens powders?
GRNS includes 40+ functional ingredients — no fillers, artificial sweeteners, or under-dosed blends — and is designed to support gut, brain, and skin health in a single scoop.