The Gut–Brain Axis: Understanding the Connection Between Digestive Health, the Microbiome & Brain Function

If you struggle with:

• Brain fog

• Poor focus

• Fatigue

• Mood fluctuations

• Low energy

• Stress sensitivity

you may have heard people talk about the connection between the gut and the brain.

Modern research increasingly recognises that the brain does not function in isolation. Instead, the brain is connected to many systems throughout the body, including:

• The digestive system

• The immune system

• The gut microbiome

• Hormonal signalling pathways

• Metabolic processes

This communication network is known as the gut–brain axis.

Researchers continue to investigate how digestive health, dietary patterns, the microbiome and lifestyle factors may influence overall wellbeing, cognitive function and quality of life.

At Broth & Co, we believe nutrition is one of the foundations of long-term wellbeing. This guide explores the science behind the gut–brain axis, the microbiome, intestinal permeability, nutrition and how these systems interact within the body.

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What Is the Gut–Brain Axis?

The gut and brain communicate continuously through multiple pathways, including:

• The vagus nerve

• Hormonal signalling

• Immune pathways

• Microbial metabolites

• Nervous system signalling

Together, these pathways form what scientists refer to as the gut–brain axis.

Researchers continue to investigate how this communication network may influence:

• Mood

• Cognition

• Stress responses

• Energy levels

• Overall wellbeing

Although much remains to be learned, it is increasingly recognised that digestive health and brain function are closely interconnected.

At Broth & Co, the gut–brain connection sits at the centre of our food-first philosophy for supporting overall wellbeing.

Modern research continues to explore the relationship between digestive health, nutrition, metabolism, recovery and healthy ageing, highlighting the important role that food and lifestyle play in supporting the body's interconnected systems.

This food-first approach focuses on:

• Energy and vitality

• Resilience and recovery

• Metabolic wellbeing

• Digestive health

• Healthy ageing

• Long-term wellness

In this guide, we explore:

• Intestinal permeability

• The gut–brain axis

• Gut microbiome diversity

• Digestive wellbeing

• Inflammation and lifestyle factors

• Probiotics and fermented foods

• Mitochondrial health and energy production

• Functional proteins, including bone broth and collagen

We'll also examine how these interconnected systems may influence:

• Cognitive function

• Mood and wellbeing

• Energy levels

• Recovery

• Healthy ageing

• Overall quality of life

While research in these areas continues to evolve, one thing remains clear: building a strong nutritional foundation through whole foods, quality protein, fibre-rich foods, healthy lifestyle habits and functional nutrition may help support long-term health and wellbeing.

At Broth & Co, this philosophy is reflected in our commitment to real food nutrition, including bone broth and collagen-based functional proteins that can be incorporated into balanced dietary patterns and active lifestyles.

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Where Does the Microbiome Live?

The gut microbiome refers to the trillions of microorganisms that reside primarily within the large intestine.

These microorganisms interact with many aspects of human physiology and contribute to:

• Digestion

• Nutrient metabolism

• Immune activity

• Production of microbial metabolites

• Overall digestive wellbeing

Researchers continue to investigate how the microbiome communicates with the brain through the gut–brain axis.

Many of these interactions occur through compounds produced by gut microbes, including short-chain fatty acids and other signalling molecules.

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Understanding Intestinal Permeability

The digestive tract contains a specialised barrier that helps regulate the movement of nutrients and other substances between the gut and the bloodstream.

Researchers use the term intestinal permeability to describe how substances move across this barrier. Most people refer to this as "leaky gut"

The intestinal lining contains structures often referred to as tight junctions, which help regulate this process.

Interest in intestinal permeability has increased significantly over recent years, with researchers investigating how it may relate to digestive health, immune activity and overall wellbeing.

While much remains under investigation, dietary quality, lifestyle habits and microbiome diversity are all considered important components of digestive health.

Understanding Intestinal Permeability

The intestinal lining acts as a highly selective barrier between the digestive tract and the rest of the body.

This barrier contains specialised structures known as tight junctions, which help regulate the movement of water, nutrients and other substances across the intestinal wall.

Researchers use the term intestinal permeability to describe how substances move across this barrier.

Under normal conditions, the intestinal barrier helps regulate what is absorbed from the digestive tract while supporting normal digestive and immune function.

Interest in intestinal permeability has increased significantly over recent years as researchers continue to investigate its relationship with digestive health, immune activity and overall wellbeing.

When the function of this barrier is altered, substances within the digestive tract may interact differently with the immune system and surrounding tissues.

Researchers are exploring how changes in intestinal permeability may be associated with:

• Digestive wellbeing

• Immune function

• Microbiome diversity

• Dietary quality

• Overall health and wellbeing

Factors that may influence gut barrier function include:

• Dietary patterns

• Gut microbiome composition

• Stress

• Sleep quality

• Physical activity

• Medication use

• Overall lifestyle habits

While research in this area continues to evolve, maintaining a nutrient-dense diet, adequate protein intake, sufficient fibre, hydration and healthy lifestyle habits remains an important foundation for supporting digestive health.

At Broth & Co, we view intestinal permeability as one part of a broader gut health picture that includes digestive wellbeing, microbiome diversity, dietary quality and overall nutritional status.

The Gut–Brain Axis and Blood–Brain Barrier Function

The brain is protected by a highly specialised structure known as the blood–brain barrier (BBB).

This barrier helps regulate the movement of substances between the bloodstream and the brain and plays an important role in maintaining the brain's internal environment.

The blood–brain barrier helps regulate:

• Nutrients entering the brain

• Immune signalling

• Metabolic by-products

• Communication between the nervous system and the rest of the body

You may occasionally hear the term "leaky brain" used online or in popular health discussions.

While "leaky brain" is not a recognised medical diagnosis, it is often used to describe changes in the permeability or function of the blood–brain barrier that researchers continue to investigate.

Scientists are increasingly exploring how factors such as:

• Chronic stress

• Poor sleep

• Dietary quality

• Metabolic health

• Inflammation-related processes

• Gut microbiome activity

may influence the gut–brain axis and blood–brain barrier function.

Because the gut, immune system and brain communicate continuously, researchers are interested in understanding how changes in one system may influence the others.

Areas currently being investigated include potential relationships between blood–brain barrier function and:

• Cognitive performance

• Mental wellbeing

• Energy levels

• Concentration and focus

• Stress resilience

• Healthy ageing

Some people experiencing poor digestive health, chronic stress or inadequate recovery may also report symptoms such as:

• Brain fog

• Fatigue

• Reduced concentration

• Low mental energy

• Increased stress sensitivity

However, these symptoms can have many potential causes, and research into the relationship between gut health, the blood–brain barrier and cognitive wellbeing continues to evolve.

What remains clear is that healthy lifestyle habits—including quality nutrition, adequate protein intake, regular physical activity, sleep and stress management—play an important role in supporting both digestive health and overall wellbeing.

Can Supporting Gut Health Influence Brain Health?

The Short Answer: Potentially—Through the Gut–Brain Axis

Researchers continue to investigate the close relationship between digestive health, the gut microbiome and brain function.

The gut and brain communicate continuously through a network of pathways known as the gut–brain axis, which involves:

• The nervous system

• The immune system

• Hormonal signalling

• The gut microbiome

Because these systems are interconnected, scientists are increasingly interested in understanding how digestive health may influence broader aspects of wellbeing.

Supporting digestive health through a balanced diet and healthy lifestyle habits may contribute to:

• Improved dietary quality

• Better nutrient absorption

• Healthy microbiome diversity

• Overall wellbeing

• Long-term health

At Broth & Co, we view digestive health as an important foundation for overall wellness because the gut plays a central role in nutrient metabolism, immune activity and communication throughout the body.

Why Digestive Health Matters Beyond Digestion

Researchers continue to investigate how digestive health may influence broader aspects of wellbeing through the gut–brain axis, immune system and microbiome.

Supporting digestive health through nutrient-dense foods, adequate protein intake, fibre-rich foods and healthy lifestyle habits may contribute to:

• Improved nutrient absorption and utilisation

• Healthy microbiome diversity

• Balanced immune function

• Overall wellbeing

• Long-term health and resilience

Researchers are also exploring how digestive health may influence processes associated with:

• Immune activity

• Inflammatory responses

• Metabolic health

• Energy production

• Cognitive wellbeing

Because the digestive tract plays a central role in nutrient absorption, maintaining digestive wellbeing helps ensure the body has access to the nutrients required for normal physiological function.

At Broth & Co, we view gut health as one of the foundations of overall wellness. This is why our food-first philosophy focuses on building a strong nutritional foundation through quality protein, functional proteins such as bone broth and collagen, fibre-rich foods, hydration and healthy lifestyle habits.

Rather than focusing on a single symptom or outcome, the goal is to support the body's interconnected systems—including digestion, metabolism, recovery, immune function and healthy ageing—through consistent nutrition and lifestyle practices.

The Gut Is One Piece of a Larger Picture

The gut–brain axis highlights the close relationship between digestive health and overall wellbeing, but it is important to recognise that gut health is only one part of a much larger picture.

Brain health, cognitive function and healthy ageing are influenced by many interconnected factors, including:

• Sleep quality

• Stress management

• Physical activity

• Blood sugar regulation

• Dietary quality

• Nutritional adequacy

• Social connection

• Mitochondrial function and energy production

• Metabolic health

Researchers increasingly recognise that these systems do not operate independently. Instead, they work together to influence energy levels, recovery, resilience, cognitive wellbeing and overall health.

This is why many health professionals advocate a whole-body approach that focuses on building strong foundations through:

• Nutrient-dense whole foods

• Adequate protein intake

• Functional proteins such as bone broth and collagen

• Fibre-rich foods

• Hydration

• Quality sleep

• Stress management

• Regular physical activity

While supporting digestive health may be an important part of this approach, it works best when combined with broader nutrition and lifestyle strategies that support the body's interconnected systems.

At Broth & Co, we believe that long-term wellbeing is built through consistent daily habits, with gut health, metabolic health, recovery and healthy ageing all forming part of the same picture.

Building a Strong Foundation

Research consistently highlights the importance of foundational lifestyle habits, including:

• Eating a nutrient-dense whole-food diet

• Consuming adequate protein

• Increasing fibre-rich foods

• Supporting microbiome diversity

• Managing stress

• Prioritising sleep

• Staying physically active

Functional foods such as bone broth and collagen can be incorporated into these broader nutrition strategies by contributing protein, collagen-derived amino acids and overall dietary quality.

Rather than viewing gut health and brain health as separate concepts, modern research increasingly recognises them as interconnected systems that influence overall wellbeing and healthy ageing throughout life.

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Inflammation: Exploring the Connection Between the Gut, Immune System and Brain

One of the most fascinating areas of modern health research is the relationship between the digestive system, immune system and brain.

These systems are in constant communication and form part of what is often referred to as the gut–brain–immune axis.

The Role of the Immune System

The immune system plays an important role in helping the body respond to everyday environmental challenges and maintain normal physiological function.

Researchers continue to investigate how the digestive tract, gut microbiome and immune system interact with one another and how these interactions may influence overall wellbeing.

Because a significant proportion of immune activity occurs within the digestive tract, scientists are increasingly interested in understanding how digestive health may influence broader aspects of health.

The Gut–Brain–Immune Connection

Research suggests that the gut, immune system and brain communicate through multiple pathways, including:

• Nervous system signalling

• Immune signalling

• Hormonal communication

• Gut microbiome activity

This communication network helps explain why digestive health, immune function and overall wellbeing are often interconnected.

Researchers are currently exploring how factors such as:

• Dietary quality

• Gut microbiome diversity

• Sleep quality

• Stress levels

• Physical activity

• Metabolic health

may influence these systems and their interactions.

Inflammation as a Whole-Body Process

Inflammation is a normal physiological response that plays an important role in health and recovery.

Rather than occurring in isolation, researchers increasingly view inflammatory processes as part of a broader network involving the digestive system, immune system, metabolism and nervous system.

This has led to growing interest in lifestyle factors that support overall wellbeing, including:

• Nutrient-dense diets

• Adequate protein intake

• Fibre-rich foods

• Physical activity

• Stress management

• Quality sleep

• Healthy body composition

Supporting the Body's Natural Recovery Processes

While no single food or lifestyle factor determines health outcomes, research consistently highlights the importance of building strong foundations through nutrition and healthy habits.

A balanced dietary pattern that includes:

• Quality protein

• Functional proteins such as bone broth and collagen

• Vegetables and fruit

• Fibre-rich foods

• Healthy fats

• Adequate hydration

can contribute to overall dietary quality and support long-term wellbeing.

At Broth & Co, we believe that supporting digestive health, recovery, resilience and healthy ageing starts with a food-first approach that nourishes the body's interconnected systems rather than focusing on any one pathway in isolation.

For more practical strategies, explore our guide:
How to Reduce Inflammation Naturally Through Nutrition and Lifestyle.

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Building a Strong Foundation for Microbiome Health

When discussing gut health, probiotics often receive most of the attention.

However, many health professionals emphasise that a healthy digestive environment is built upon a broader foundation.

Important factors include:

• Adequate protein intake

• Fibre-rich foods

• Hydration

• Dietary variety

• Sleep quality

• Physical activity

• Stress management

These lifestyle habits help support digestive wellbeing and create an environment that may encourage microbiome diversity.

Rather than relying on a single supplement or intervention, long-term digestive health is typically supported through consistent daily habits.

Why Probiotics Don't Always Deliver the Same Results

Probiotics have become one of the most widely discussed topics in gut health.

However, researchers increasingly recognise that probiotic supplements are only one part of a much larger digestive health picture.

The gut microbiome is influenced by many factors, including:

• Dietary quality

• Fibre intake

• Protein intake

• Physical activity

• Sleep quality

• Stress levels

• Medication use

• Overall lifestyle habits

This means that introducing probiotics alone may not always produce the same outcomes for every individual.

The Importance of the Gut Environment

Many gut health experts now emphasise that creating a supportive digestive environment is just as important as introducing beneficial bacteria.

A healthy digestive environment is supported by:

• Adequate fibre intake

• Diverse plant foods

• Quality protein sources

• Hydration

• Regular physical activity

• Sleep and recovery

• Stress management

These factors help support overall digestive wellbeing and may contribute to greater microbiome diversity over time.

Building the Foundation First

At Broth & Co, we believe that gut health starts with foundational nutrition.

Before focusing on individual supplements, it is often valuable to consider the broader dietary pattern.

This includes:

• Eating a variety of whole foods

• Increasing vegetable intake

• Consuming adequate protein

• Including functional proteins such as bone broth and collagen

• Prioritising fibre-rich foods

• Supporting hydration and recovery

Bone broth can play a role within this approach by providing protein, collagen-derived amino acids and a nourishing whole-food option that can be easily incorporated into everyday meals.

A Whole-Food Approach to Microbiome Health

Research increasingly suggests that microbiome diversity is influenced by long-term dietary and lifestyle patterns rather than any single food, probiotic or supplement.

This is why many modern gut-health strategies focus on building resilience through:

• Dietary quality

• Nutritional adequacy

• Microbiome diversity

• Digestive wellbeing

• Healthy lifestyle habits

Probiotics may have a role within this broader framework, but they are generally most effective when combined with a strong nutritional foundation and a diverse, whole-food dietary pattern.

At Broth & Co, this philosophy is reflected in our food-first approach to gut health, where functional proteins, fibre-rich foods, hydration and balanced nutrition work together to support long-term digestive wellbeing.

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Bone Broth and the Gut–Brain Axis

Bone broth has become increasingly popular within whole-food nutrition approaches because it provides protein and collagen-derived amino acids in a convenient and versatile format.

Bone broth naturally contains amino acids including:

• Glycine

• Proline

• Hydroxyproline

• Glutamine

These amino acids contribute to overall dietary protein intake and form part of the broader amino acid pool available from foods consumed throughout the day.

Bone broth is best viewed as one component of a balanced dietary pattern that emphasises:

• Quality protein

• Fibre-rich foods

• Vegetables and fruit

• Hydration

• Dietary variety

Many people use bone broth as a nourishing base for soups, stews and whole-food meals that contribute to overall dietary quality.

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The Broth & Co Gut Health Study

In 2021, Broth & Co conducted an Australian consumer study investigating the effects of daily bone broth consumption over an eight-week period.

One of the outcomes measured was the mannitol:lactulose ratio, a research marker commonly used to assess intestinal permeability and gut barrier function.

Participants demonstrated improvements in this marker over the course of the study, suggesting positive changes in measures associated with gut barrier integrity.

Participants also reported improvements in digestive wellbeing, including reductions in bloating and food sensitivities.

While further research is needed and individual results may vary, these findings contribute to growing interest in the role that nutrient-dense foods and overall dietary patterns may play in supporting digestive health.

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Glycine and Collagen-Rich Foods

Glycine is one of the most abundant amino acids found in collagen-rich foods such as:

• Bone broth

• Collagen peptides

• Gelatin

• Slow-cooked connective tissues

Researchers continue to investigate the role of glycine in numerous normal physiological processes throughout the body.

Because modern diets often contain less connective tissue than traditional diets, glycine-rich foods have become an area of growing interest within nutrition research.

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Glutamine and Digestive Wellbeing

Glutamine is naturally present in a variety of protein-rich foods and is utilised throughout the body.

Researchers continue to investigate its relationship with digestive health and overall wellbeing.

Bone broth naturally contains glutamine alongside other collagen-derived amino acids, making it a popular food within whole-food nutrition approaches.

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At Broth & Co, functional mushrooms are combined with collagen-rich bone broth in our Energy Performance Bone Broth range as part of a whole-food nutrition approach.

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Mitochondria, Brain Energy and Cognitive Wellbeing

The brain is one of the body's most energy-demanding organs.

Although it represents only a small percentage of total body weight, it requires a significant amount of the body's energy to support normal cognitive function, concentration, memory and communication between nerve cells.

This is why researchers are increasingly interested in the relationship between:

• Mitochondrial function

• Metabolic health

• Nutritional status

• Sleep quality

• Physical activity

• Brain health and healthy ageing

What Are Mitochondria?

Mitochondria are often referred to as the body's energy-producing structures.

They are found in almost every cell and play an important role in converting nutrients from food into usable cellular energy.

Because the brain has such high energy requirements, maintaining healthy mitochondrial function is increasingly recognised as an important component of overall wellbeing.

Researchers continue to investigate how factors such as dietary quality, physical activity and healthy lifestyle habits may influence mitochondrial health throughout life.

Brain Energy and Everyday Wellbeing

Many people experience periods of:

• Mental fatigue

• Reduced concentration

• Low energy

• Difficulty focusing

These experiences can be influenced by many factors including:

• Sleep quality

• Stress levels

• Dietary habits

• Physical activity

• Hydration

• Blood glucose regulation

• Overall health status

For this reason, many nutrition and lifestyle strategies focus on supporting the body's energy-producing systems through consistent healthy habits rather than any single intervention.

Nutrition and Mitochondrial Health

The body's energy-producing systems rely on a consistent supply of nutrients from food.

Nutrition strategies commonly associated with supporting overall metabolic and cellular health include:

• Consuming adequate protein

• Eating nutrient-dense whole foods

• Including a variety of colourful vegetables and fruit

• Maintaining regular meal patterns

• Supporting healthy blood glucose regulation through balanced meals

• Staying physically active

• Prioritising sleep and recovery

Protein is particularly important because amino acids contribute to numerous physiological processes throughout the body, including the maintenance and renewal of tissues.

Functional Proteins and Energy Nutrition

At Broth & Co, we believe that functional proteins can play a valuable role within a broader whole-food nutrition approach.

Bone broth provides approximately 5g of naturally occurring protein per serve, together with collagen-derived amino acids including glycine, proline and glutamine.

Collagen peptides can also contribute additional protein intake as part of a balanced dietary pattern.

While no single food determines energy levels or cognitive performance, nutrient-dense foods and adequate protein intake help support overall dietary quality and provide the nutritional building blocks required for normal physiological function.

Supporting Brain Health Through a Whole-Body Approach

Researchers increasingly recognise that brain health is connected to many aspects of overall wellbeing, including:

• Digestive health

• Metabolic health

• Physical activity

• Sleep quality

• Stress management

• Nutritional adequacy

This is why many modern wellness approaches focus on supporting the body's interconnected systems rather than targeting a single pathway in isolation.

At Broth & Co, our philosophy centres on building strong nutritional foundations through real food, functional proteins, balanced meals and healthy lifestyle habits that support long-term wellbeing and healthy ageing.

👉 Related:
Mitochondrial Support Guide: Foods, Lifestyle Strategies and Functional Nutrition for Energy and Healthy Ageing

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Nutrition, Energy and Cognitive Performance

Food provides the nutrients required for normal physiological function.

Balanced meals that include:

• Protein

• Fibre-rich foods

• Healthy fats

• Whole-food carbohydrates

can contribute to overall dietary quality and help support consistent eating patterns throughout the day.

Many people find that prioritising nutrient-dense foods helps them maintain more consistent energy levels and support their overall wellbeing.

Related:

Discover how BC Beauty Skinny Glow with Nextida® supports natural GLP-1 release, satiety, glucose control, metabolism, skin health and healthy weight management with bioactive collagen peptides.

Bone Broth & Collagen as Functional Proteins: A Deeper Look at Repair, Recovery & Resilience

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Sleep, Stress and the Gut–Brain Axis

Sleep and stress are important influences on overall health.

Researchers continue to investigate how sleep quality and stress levels interact with:

• Digestive health

• Immune activity

• Metabolic function

• Overall wellbeing

Poor sleep and chronic stress may influence many aspects of health, including food choices, energy levels and digestive comfort.

This is why healthy lifestyle strategies often focus on:

• Good sleep habits

• Stress management

• Physical activity

• Nutritious food choices

rather than relying on a single intervention.

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Foods Commonly Included in Gut–Brain Health Dietary Patterns

Researchers continue to investigate how dietary patterns influence digestive health, the microbiome and overall wellbeing.

Foods commonly included in gut-focused dietary patterns include:

Bone Broth

Bone broth provides protein and collagen-derived amino acids and can be incorporated into balanced dietary patterns that emphasise whole foods and dietary variety.

Vegetables and Fruit

Provide fibre and a wide range of nutrients that contribute to overall dietary quality.

Fermented Foods

Foods such as yoghurt, kefir, kimchi and sauerkraut contribute dietary variety and are commonly included within microbiome-focused eating patterns.

Functional Mushrooms

Mushrooms such as shiitake contain naturally occurring compounds including fibre and beta-glucans and are increasingly being explored within nutrition research.

Quality Protein Sources

Protein-rich foods such as fish, eggs, poultry, legumes, dairy foods and bone broth contribute to overall dietary quality and nutritional adequacy.

Functional Proteins for Recovery

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Gut–Brain Support Bone Broth Recipe

Ingredients

• 4 cups bone broth

• 2 cloves garlic, crushed

• 1 teaspoon grated ginger

• 1 cup sliced shiitake mushrooms

• 2 cups spinach

• ½ teaspoon turmeric

• Freshly cracked black pepper

• Spring onion to serve

• 1 star anise

Method

1. Lightly sauté garlic, ginger and mushrooms.

2. Add bone broth, turmeric, star anise and black pepper.

3. Simmer for 10–15 minutes.

4. Stir through spinach just before serving.

5. Garnish with spring onion and serve warm.

This simple recipe combines bone broth, vegetables and mushrooms as part of a nutrient-dense meal.

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Final Thoughts

The gut, microbiome, immune system and brain are interconnected through a complex communication network known as the gut–brain axis.

Researchers continue to investigate how factors such as:

• Dietary quality

• Microbiome diversity

• Sleep

• Physical activity

• Stress management

• Nutrition

may influence overall wellbeing.

Rather than focusing on a single food or supplement, the most effective long-term approach is often a balanced dietary pattern built around nutrient-dense whole foods and healthy lifestyle habits.

Within this framework, foods such as bone broth, collagen-rich proteins, vegetables, fibre-rich foods and functional mushrooms can contribute to a varied and nourishing way of eating that supports overall health and wellbeing.

👉 Explore options: Shop healing Bone Broth here

👉Learn more: Benefits of Bone Broth - The Ultimate Guide

Frequently Asked Questions

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 pathways and the microbiome.

Where does the microbiome live?

The majority of gut microorganisms reside within the large intestine.

What is intestinal permeability?

Intestinal permeability refers to how substances move across the intestinal barrier. Researchers continue to investigate its relationship to digestive health and overall wellbeing.

Can gut health affect mood?

Researchers continue to investigate how the gut–brain axis may influence mood, cognition and overall wellbeing.

Does bone broth support digestive health?

Bone broth provides protein and collagen-derived amino acids and can be incorporated into balanced dietary patterns that support digestive wellbeing and overall dietary quality.