If you struggle with bloating, food sensitivities, fatigue, skin issues, brain fog, or autoimmune symptoms, you may have come across the term leaky gut.

While it may sound like a trendy health buzzword, leaky gut refers to a real phenomenon known as increased intestinal permeability. Research suggests that disruptions to the gut barrier may play a role in digestive issues, inflammation, immune dysfunction, and certain chronic health conditions.

What Is Leaky Gut?

Your intestinal lining acts as a protective barrier between the contents of your digestive tract and the rest of your body.

This barrier is designed to allow nutrients from food to pass into the bloodstream while keeping harmful substances, toxins, bacteria, and undigested food particles contained within the digestive tract.

When the gut lining becomes damaged or compromised, the spaces between intestinal cells can become more permeable than normal. This increased permeability may allow unwanted substances to pass through the intestinal barrier and interact with the immune system.

This is what is commonly referred to as leaky gut.

Common Symptoms Associated with Leaky Gut

Because the gut plays a role in digestion, immunity, and inflammation, symptoms can extend beyond the digestive system.

Common symptoms may include:

Bloating
Gas
Food sensitivities
Diarrhea or constipation
Abdominal discomfort
Fatigue
Brain fog
Headaches
Skin issues such as eczema or acne
Joint pain
Autoimmune symptoms
Nutrient deficiencies

It's important to remember that these symptoms can have many potential causes. Leaky gut is often one piece of a larger health picture.

What Causes Leaky Gut?

1. Chronic Stress

The gut and brain are closely connected.

Long-term stress can affect digestion, alter the gut microbiome, and contribute to inflammation that may weaken the intestinal barrier over time.

2. Poor Diet

A diet high in ultra-processed foods, refined sugars, and inflammatory oils may contribute to gut irritation and inflammation.

At the same time, a lack of fiber-rich fruits, vegetables, and whole foods may negatively impact the gut microbiome.

3. Gut Infections and Dysbiosis

Bacterial overgrowth, parasites, yeast overgrowth, and imbalances in the gut microbiome can damage the intestinal lining and contribute to increased permeability.

4. Food Sensitivities

Certain foods may trigger inflammation in susceptible individuals.

For some people, ongoing exposure to foods that provoke an immune response can contribute to gut irritation and symptoms.

5. Medications

Certain medications may affect the gut lining, including:

NSAIDs (such as ibuprofen)
Frequent antibiotic use
Acid-blocking medications in some cases

6. Chronic Inflammation

Underlying inflammatory conditions may further impair the integrity of the gut barrier and make healing more difficult.

Why Does Gut Health Matter?

Approximately 70% of the immune system is located within or around the digestive tract.

When the gut barrier is functioning properly, it helps regulate immune activity and maintain a healthy balance between the body and the outside world.

When the barrier becomes compromised, it may contribute to ongoing inflammation and immune activation.

This is one reason functional medicine practitioners often evaluate gut health when addressing chronic symptoms.

How Is Leaky Gut Evaluated?

There is no single test that definitively diagnoses leaky gut.

However, practitioners may use a combination of:

Comprehensive stool testing
Food sensitivity testing
Organic acid testing
Inflammatory markers
Clinical history and symptoms

The goal is to identify potential root causes contributing to gut dysfunction.

How to Support Gut Healing

Healing the gut often requires addressing the factors that caused the problem in the first place.

Common strategies may include:

Removing inflammatory triggers
Supporting a healthy gut microbiome
Improving nutrition
Managing stress
Supporting digestion
Correcting nutrient deficiencies
Identifying and treating infections when present

Because each person's situation is unique, treatment plans should be individualized.

The Bottom Line

Leaky gut, or increased intestinal permeability, occurs when the protective barrier of the digestive tract becomes compromised.

While leaky gut itself is not always the primary problem, it may contribute to symptoms such as bloating, food sensitivities, fatigue, brain fog, skin issues, and inflammation.

By identifying and addressing the underlying root causes, it is often possible to support gut healing and improve overall health.