If you've spent any time researching gut health, you've probably come across the term leaky gut. And you've probably also noticed that opinions on it vary wildly. Some practitioners talk about it constantly. Others dismiss it entirely. And if you've ever brought it up with a conventional doctor, there's a good chance they looked at you skeptically.

So what's actually going on? Is leaky gut a real thing? Does it matter? And if you have it, what do you do about it?

Let me give you a straight answer, because this is an area where the confusion is genuinely unhelpful for people trying to understand what's happening in their body.

What Leaky Gut Actually Is

The clinical term for leaky gut is intestinal hyperpermeability, and yes, it is a real and measurable phenomenon.

Your gut lining is a single layer of cells held together by tight junctions, small protein structures that act like gatekeepers, controlling what passes from the gut into the bloodstream. In a healthy gut, this barrier allows nutrients, water, and electrolytes through while keeping bacteria, undigested food particles, and toxins out.

When the tight junctions become compromised, that barrier starts to break down. Gaps open up that allow things through that shouldn't be crossing into the bloodstream. The immune system responds to these foreign particles, triggering inflammation. And that inflammation can show up in a lot of different ways throughout the body.

So leaky gut isn't a diagnosis in the way that SIBO or a thyroid condition is a diagnosis. It's a description of what's happening at the gut lining level, and it's a significant one because of the downstream effects it can have.

What Causes It

There are quite a few things that can compromise the gut lining and contribute to intestinal hyperpermeability.

Bacterial overgrowth is one of them. SIBO and microbiome imbalances in the large intestine both produce byproducts that damage the gut lining over time. This is part of why leaky gut and SIBO so commonly coexist, and why treating SIBO without also supporting gut lining repair is a missed step.

Chronic stress, as we covered in the post on stress and gut health, increases gut permeability directly. Elevated cortisol weakens the tight junctions and reduces the production of the mucus layer that protects the gut lining.

Diet plays a role too. Gluten, for example, triggers the release of a protein called zonulin in most people, which loosens the tight junctions. In people with already compromised gut lining, this can be a significant contributing factor. Alcohol, processed foods, and certain medications including NSAIDs and antibiotics also affect gut lining integrity.

Hormonal imbalances, which we explored in the post on hormones and gut health, can contribute as well. Estrogen has a protective effect on the gut lining, so fluctuations in estrogen levels can affect its integrity.

And then there's mold exposure, which doesn't get talked about enough. Mycotoxins from mold can directly damage the gut lining and are a surprisingly common hidden contributor to persistent gut symptoms, particularly in people who have lived or worked in water-damaged buildings.

What Symptoms It Can Cause

This is where it gets interesting, because leaky gut doesn't just cause gut symptoms.

Within the digestive system, it can contribute to bloating, food reactions, abdominal discomfort, and worsening food sensitivities over time. If your list of foods you can tolerate keeps shrinking, that's often a sign that the gut lining is involved.

Beyond the gut, the effects can be wide-ranging. Skin conditions like acne, eczema, and rosacea often have a gut lining component. Brain fog and difficulty concentrating can result from inflammatory molecules crossing into the bloodstream and affecting neurological function. Joint pain and fatigue are other common presentations. Autoimmune conditions are increasingly being linked to intestinal hyperpermeability as a contributing factor, because when the immune system is repeatedly exposed to particles it shouldn't be seeing, it can start to lose its ability to distinguish between foreign invaders and the body's own tissue.

This is why leaky gut matters beyond just the gut. It's not a trendy wellness term. It's a real physiological state with real systemic consequences.

Does Everyone With Gut Issues Have Leaky Gut?

Not necessarily, but it's very common in people with SIBO, IBS, and chronic digestive issues, particularly those who have been unwell for a long time or who have done multiple rounds of antimicrobials without a rebuilding phase.

The gut lining is also one of the faster-healing tissues in the body when it's given the right support, which is the encouraging part. You don't need to be dealing with this indefinitely.

What Actually Helps

Supporting gut lining repair is a specific area of clinical work that requires the right tools in the right order.

Removing the things that are damaging the lining is the first step. This might mean addressing SIBO, reducing dietary irritants, managing stress, or investigating mold exposure, depending on what's driving the damage.

From there, specific nutrients and herbs support the repair process. L-glutamine is one of the most well-researched, as it's a primary fuel source for the cells lining the gut. Zinc carnosine has good evidence for supporting gut lining integrity. Demulcent herbs like slippery elm and marshmallow root soothe and protect the gut lining. Colostrum is another option with good clinical support. Bone broth, which contains collagen, glycine, and gelatin, can be genuinely helpful as a food-based support.

Rebuilding the microbiome is also part of this picture, because a healthy, diverse microbiome produces short-chain fatty acids that are essential for maintaining the health and integrity of the gut lining. A depleted microbiome means less of this protective support.

The key point is that gut lining support needs to happen alongside, or after, treating the underlying cause. Trying to repair the lining while the thing that's damaging it is still present is an uphill battle.

How We Approach This at The Gut Clinic

Gut lining integrity is something we assess and address as part of every client's program. It's not a separate add-on. It sits within the broader work of rebuilding the digestive system properly after treatment.

In our Gut Restoration Program, the repair and rebuilding phases are where this work happens. We look at what's been driving the damage, support the lining with the right clinical tools for each person, and work to restore microbiome diversity alongside it, because these two things are deeply connected.

If you've been dealing with multiple food sensitivities that keep getting worse, symptoms that extend beyond the gut, or a sense that your system just keeps getting more reactive over time, leaky gut is worth taking seriously as part of the picture.

If you'd like to talk through what's going on for you and whether gut lining repair might be a missing piece, our Discovery Calls are a good place to start.

Book a free Discovery Call here

Lots of love, Kirsten