Understanding Leaky Gut: All-You-Need-to-Know Functional Medicine Perspective 

Written By


Expert Reviewed By

Dr. Lauryn Lax, OTD, MS

Dr. Lauryn, OTD, MS is a doctor of occupational therapy, clinical nutritionists and functional medicine expert with 25 years of clinical and personal experience in healing from complex chronic health issues and helping others do the same.

Leaky Gut - Woman Sitting On Sofa Having Stomachache

In recent years, the human gut has emerged as a complex and fascinating ecosystem teeming with trillions of microorganisms, which play a pivotal role in our overall health. This intricate network of gut microbes, collectively known as the microbiome, influences various aspects of our well-being, from digestion and metabolism to immune function. As a health-conscious individual, who loves biohacking your health, it’s essential to grasp the significance of a phenomenon called “leaky gut” in the context of functional medicine.

And of course: if you’re looking for personal support, let’s optimize your gut and take your health back into your own hands! Book a complimentary 20-minute Health Strategy Call today. 

What Is Leaky Gut?

Leaky gut, scientifically known as increased intestinal permeability, refers to a condition where the lining of the gastrointestinal tract becomes overly porous, allowing substances that should remain in the gut to escape into the bloodstream. In essence, the gut barrier, which normally acts as a gatekeeper, loses its integrity and starts permitting the entry of harmful pathogens, toxins, and undigested food molecules into the body. This malfunction can trigger a cascade of health issues, including chronic inflammation, autoimmune diseases, skin disorders, depression, and even obesity.

The Microbiome: More Microbe than Human

Leaky Gut - Woman Pointing Finger To Belly

Before delving into the intricacies of leaky gut, it’s crucial to understand the profound influence of the gut microbiome on our health. The human body contains ten times more microbes than human cells, with these microorganisms possessing a hundred times more genes than our entire human genome. This staggering fact emphasizes that we are, at a cellular level, more microbe than human.

The gut microbiome plays pivotal roles in promoting gastrointestinal health, safeguarding against infections, regulating metabolism, and hosting a majority of our immune cells. Any disturbances in this delicate balance can lead to a wide range of diseases, from thyroid disorders to neurological conditions.

The Gut-Brain Connection

One of the most intriguing aspects of gut health is its profound connection with the brain. Research has demonstrated that the gut and the brain engage in a bidirectional relationship, meaning that problems in one can influence the other. The gut-brain axis involves the vagus nerve, which connects the gut to the brain, facilitating communication between the two.

Issues in the gut, such as inflammation and imbalances in the microbiome, can increase the risk of brain-related conditions like dementia, autism spectrum disorders, depression, anxiety, Alzheimer’s, and Parkinson’s. Conversely, conditions affecting the brain can disrupt gut function due to the extensive neural connections between the two.

Early Life and Gut Health

The foundations of gut health are laid early in life. During childbirth, babies are exposed to their mother’s native bacteria, which significantly shapes their gut microbiome. Vaginal birth exposes infants to a different set of bacteria than Caesarean section birth, leading to long-term differences in gut health. Children born via C-section are at greater risk of conditions like asthma, obesity, and type one diabetes.

Infant feeding also plays a vital role in microbiome development. Breastfed babies have a distinct gut microbiota compared to formula-fed infants. Early pioneer bacteria, which colonize the infant gut, set the stage for the later microbial community. The absence of these pioneer species can alter gut colonization and influence health outcomes.

Factors Influencing the Adult Gut Microbiome

Leaky Gut - Young Brunette Woman Eating Italian Pasta

As adults, our lifestyle choices significantly impact the composition of our gut microbiome. Several key factors include:

Diet: The type, quantity, and balance of proteins, fats, carbohydrates, and fiber in our diet can rapidly alter gut microbiota.

Medications: Antibiotics and NSAIDs can disrupt the gut flora.

Chronic Stress: High stress levels can negatively affect the gut microbiome.

Infections: Gut infections, such as h. pylori and parasites, can increase gut permeability.

Physical Inactivity: A sedentary lifestyle can adversely affect the gut microbiota.

Leaky Gut - Young Frustrated Exhausted Woman Laid Her Head Down On The Table

The gut microbiome’s functions are categorized into metabolic, structural, and protective roles. It aids in metabolizing dietary compounds, synthesizing essential vitamins, and influencing how we process and store food. Moreover, gut microbes play a structural role by stimulating the growth of epithelial cells and regulating intestinal permeability. Finally, they have a protective function by interacting with the immune system to resist pathogenic invasions.

Understanding Zonulin: A Key Player in Gut Health

A critical factor in maintaining gut barrier integrity is a protein called zonulin. Elevated levels of zonulin have been observed in various autoimmune conditions, suggesting its involvement in increased intestinal permeability. This protein’s influence on the gut barrier highlights the complex pathophysiology of leaky gut.

The Cause and Effect Conundrum

While leaky gut is implicated in numerous health conditions, it’s important to recognize that causality is not always clear-cut. In many cases, leaky gut may be a consequence rather than a primary cause of underlying pathologies. This perspective underscores the need for a holistic approach to health, addressing not only leaky gut but also the root causes driving these disruptions in gut health.

Factors Contributing to Increased Gut Permeability

Leaky Gut - Young Upset And Tired Bearded Man Lying On Bed With Open Eyes And Cannot Sleep, Male Having Insomnia Problem Or Sleeping Troubles

Several factors have been identified as contributors to increased gut permeability, including:

Dietary Factors: Gluten consumption in individuals with celiac disease or non-celiac gluten intolerance, as well as flour, sugar, and seed oils, can affect gut permeability.

Medications: Antibiotics, NSAIDs, and aspirin can disrupt the microbiome and lead to leaky gut.

Chronic Stress: Prolonged stress can weaken the gut barrier.

Infections: Pathogenic infections like h. pylori, parasites, and bacteria can increase gut permeability.

Alcohol Consumption: Excessive alcohol intake can harm the gut lining.

Environmental Toxins: Substances like BPA and heavy metals may contribute to leaky gut.


In conclusion, leaky gut is a multifaceted phenomenon that has captured the attention of functional medicine practitioners and health enthusiasts alike. Understanding the intricate connections between the gut, the microbiome, and overall health is essential for individuals seeking to optimize their well-being through biohacking. While leaky gut is associated with a range of health conditions, it’s crucial to view it within the broader context of gut health and consider the underlying causes driving this disruption. By adopting a holistic approach to health, we can take proactive steps to support our gut, nurture a thriving microbiome, and enhance our overall vitality.

As you explore the world of functional medicine, remember that your gut is more than just a digestive organ—it’s a dynamic ecosystem that plays a central role in your health journey. Stay informed, make mindful choices, and embark on a path toward optimal well-being.

CTA: Optimize your gut and take your health back into your own hands! Book a complimentary 20-minute Health Strategy Call today and let us help you. 

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