Gut–Brain Axis & Leaky Gut: How to Restore Gut Health and Improve Intestinal Permeability

What Is the Gut–Brain Axis?

Gut health is no longer viewed as simply a digestive issue.

Research now shows that the gut influences:

Brain function
Mood and cognition
Immune health
Inflammation
Metabolism
Energy production

At the centre of this relationship is the gut–brain axis — the two-way communication network connecting the digestive system and the brain.

If you experience:

Bloating
Brain fog
Fatigue
Food sensitivities
Mood fluctuations
Poor concentration

your gut may be playing a larger role than you realise.

This guide explores:

The gut–brain axis
Leaky gut (intestinal permeability)
Gut dysbiosis
Akkermansia and the microbiome
Inflammation and brain health
Practical strategies to restore gut health naturally

Why Gut Health Matters

The gut influences virtually every major system in the body.

It helps regulate:

Nutrient absorption
Immune signalling
Hormone production
Neurotransmitter production
Inflammation levels

In fact, much of the communication between the gut and brain occurs through:

The vagus nerve
The immune system
The microbiome
Hormonal signalling

When gut health is thriving:

Digestion improves
Energy becomes more stable
Mood is often more balanced
Inflammation may decrease

When gut health is compromised, symptoms can appear throughout the body.

What Is Leaky Gut (Intestinal Permeability)?

The digestive tract is lined by a protective barrier.

Its role is simple:

Allow nutrients to enter the body while preventing unwanted substances from crossing into circulation.

When this barrier becomes compromised, intestinal permeability may increase.

This process is often referred to as "leaky gut."

When permeability increases:

Immune activation may increase
Inflammation can rise
Digestive symptoms may develop
Gut–brain communication may be affected

Leaky gut is not a medical diagnosis itself but rather a mechanism that may contribute to broader health challenges.

Common Signs of Gut–Brain Imbalance

Digestive Symptoms

Bloating
Gas
Digestive discomfort
Irregular bowel movements

Brain & Mood Symptoms

Brain fog
Poor concentration
Low mood
Increased stress sensitivity

Whole Body Symptoms

Fatigue
Food sensitivities
Skin concerns
Joint discomfort

These symptoms often appear together because the gut influences multiple systems simultaneously.

What Causes Gut Dysfunction?

Modern lifestyles create multiple pressures on the digestive system.

Diet

Ultra-processed foods
Excess sugar
Low fibre intake
Nutrient-poor diets

Lifestyle

Chronic stress
Poor sleep
Sedentary behaviour

Medications

Antibiotics
Frequent NSAID use

Biological Factors

Gut dysbiosis
Microbial imbalance
Previous infections

Most people experience a combination of these factors rather than a single cause.

The Microbiome: Your Internal Ecosystem

Your microbiome consists of trillions of bacteria living primarily within your digestive tract.

These microbes influence:

Digestion
Immune regulation
Inflammation
Metabolism
Brain function

A diverse microbiome is generally associated with:

Better digestive resilience
Stronger gut barrier integrity
Improved metabolic health

An imbalanced microbiome (dysbiosis) may contribute to inflammation and intestinal permeability.

Signs Of Gut Dysbiosis

Why Probiotics Don't Always Work

One of the most common misconceptions in gut health is that probiotics are always the first solution.

While probiotics can be helpful in certain situations, many people find they experience little benefit despite taking them consistently.

The reason is simple:

👉 The gut environment matters just as much as the bacteria themselves.

Think of gut health like a garden:

The gut lining is the soil
Prebiotic foods are the fertiliser
Probiotics are the seeds

If the soil is unhealthy, even the best seeds struggle to grow.

When the digestive environment is compromised by:

Chronic inflammation
Poor diet quality
Stress
Gut dysbiosis
Intestinal permeability

beneficial bacteria may struggle to establish themselves.

This is why many people report:

Minimal improvement
Temporary benefits
Symptoms returning after stopping probiotics

The goal is not simply adding more bacteria.

The goal is creating an environment where beneficial bacteria can thrive.

Building the Right Environment First

Before introducing probiotic supplements, it often helps to focus on foundational habits:

Reduce Dietary Stressors

Prioritise:

Whole foods
Fibre-rich foods
Diverse plant foods

Reduce:

Ultra-processed foods
Excess sugar
Excess alcohol

Support Gut Barrier Function

The gut lining acts as a protective barrier between the digestive tract and the rest of the body.

Supporting gut barrier integrity is an important part of maintaining digestive wellbeing.

Foods such as bone broth contain naturally occurring amino acids including:

Glycine
Proline
Glutamine

which can be included as part of a balanced diet.

Improve Sleep Quality

Poor sleep is associated with:

Increased inflammation
Altered microbiome diversity
Reduced recovery

Consistent sleep habits can support both gut and brain health.

Manage Stress

The gut and brain communicate constantly through the gut–brain axis.

Chronic stress may affect:

Digestion
Gut motility
Microbial balance
Inflammatory signalling

Simple daily practices such as walking, breathing exercises and mindfulness can support healthy gut–brain communication.

When Probiotics May Be More Effective

Once the gut environment has been supported through:

Improved nutrition
Better sleep
Reduced stress
Greater dietary diversity

beneficial bacteria may be more likely to thrive.

This is where probiotics may have a more meaningful role as part of an overall gut health strategy.

The key takeaway:

👉 Focus on the environment first, then the probiotics.

Long-term gut health is usually built through consistent lifestyle habits rather than relying on any single supplement.

The Role of Akkermansia in Gut Health, Metabolism & Healthy Ageing

One of the most researched beneficial gut bacteria today is Akkermansia muciniphila.

Akkermansia naturally lives within the protective mucus layer of the gut.

Researchers are particularly interested in Akkermansia because it has been associated with:

Gut barrier integrity
Healthy metabolic function
Blood sugar balance
Inflammation regulation
Healthy ageing

Why Akkermansia Matters

A healthy gut barrier relies on a healthy microbiome.

Beneficial bacteria help:

Maintain gut lining integrity
Support immune balance
Improve gut–brain communication
Support digestive resilience

Akkermansia appears to play an important role in maintaining this environment.

How to Support Akkermansia Naturally

Increase Plant Diversity

Aim for a variety of:

Vegetables
Herbs
Fruits
Legumes (if tolerated)
Whole plant foods

Consume Polyphenol-Rich Foods

Polyphenols help support microbial diversity.

Examples include:

Berries
Pomegranate
Green tea
Olive oil
Cocoa

Reduce Ultra-Processed Foods

A diet rich in whole foods generally supports a healthier microbial ecosystem.

Support Gut Lining Integrity

Foods containing amino acids such as:

Glycine
Glutamine
Proline

may help support digestive wellbeing.

Bone broth naturally provides these amino acids as part of a balanced diet.

The Gut–Inflammation Connection

One of the most important discoveries in modern nutrition science is the connection between gut health and inflammation.

When the gut barrier becomes compromised:

Immune activity may increase
Inflammatory signalling can rise
Recovery and resilience may decline

Over time, chronic inflammation may affect:

Brain function
Metabolic health
Energy production
Healthy ageing

Learn more:

Reduce Chronic Inflammation Naturally

How Gut Health Influences Brain Function

The gut and brain communicate constantly.

This communication influences:

Mood
Focus
Memory
Stress response
Sleep quality

Gut bacteria help produce compounds that influence the nervous system.

This is one reason digestive issues and brain-related symptoms often appear together.

Improving gut health may positively influence:

Mental clarity
Energy levels
Overall wellbeing

How to Restore Gut Health Naturally

1. Remove Gut Stressors

Reduce:

Ultra-processed foods
Excess sugar
Excess alcohol

This may help lower inflammatory load.

2. Support Gut Lining Integrity

One of the simplest foundational foods for digestive wellbeing is bone broth.

Bone broth naturally provides:

Glycine
Glutamine
Proline
Collagen-derived amino acids

These nutrients support overall digestive health as part of a balanced diet.

Learn more:

The Complete Bone Broth Guide

3. Improve Microbial Diversity

Focus on:

Vegetables
Fibre-rich foods
Herbs
Spices
Colourful plant foods

Greater dietary diversity generally supports greater microbial diversity.

4. Prioritise Sleep

Sleep affects:

Gut bacteria
Immune regulation
Recovery
Brain function

Poor sleep can negatively affect both gut and brain health.

5. Manage Stress

Stress directly affects:

Digestion
Gut barrier function
Microbial balance

Helpful strategies include:

Walking
Breathwork
Mindfulness
Time outdoors

6. Support Mitochondrial Health

Healthy energy production supports every system in the body.

Including:

Gut repair
Brain function
Recovery

Best Foods for Mitochondrial Health

Where Bone Broth Fits In

Bone broth is a traditional food that supports multiple systems simultaneously.

It provides:

Hydration
Amino acids
Minerals
Collagen-derived nutrients

Many people incorporate bone broth as part of a broader gut-supportive lifestyle because it is:

Easy to digest
Nutrient dense
Convenient to use daily

Explore options:

Broth & Co Bone Broth & Collagen Peptides

The Bigger Picture: Gut Health Is a System

Gut health is rarely about one food, one supplement or one protocol.

Everything interacts:

Gut barrier integrity
Microbiome diversity
Inflammation
Mitochondrial function
Stress
Sleep

Improving one area often positively influences the others.

Final Thoughts

The gut–brain axis sits at the centre of many aspects of health.

When you support:

Gut lining integrity
Microbial diversity
Inflammation balance
Energy production

you create a stronger foundation for:

Digestion
Mood
Cognitive function
Metabolic health
Healthy ageing

The goal is not perfection.

The goal is consistency.

Simple daily habits, nutrient-dense foods and a focus on gut health can have a meaningful impact on overall wellbeing over time.

FAQ

What is the gut–brain axis?

The gut–brain axis is the communication network linking the digestive system and the brain through nerves, hormones, immune signals and the microbiome.

What is leaky gut?

Leaky gut refers to increased intestinal permeability, where the gut barrier becomes less effective at regulating what passes into circulation.

What causes gut dysbiosis?

Common contributors include ultra-processed foods, low fibre intake, chronic stress, poor sleep, antibiotics and lifestyle factors.

How does bone broth support gut health?

Bone broth provides amino acids such as glycine, glutamine and proline along with collagen-derived nutrients that support digestive wellbeing as part of a balanced diet.

What is Akkermansia?

Akkermansia muciniphila is a beneficial gut bacteria associated with gut barrier integrity, metabolic health and healthy ageing.

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