Dr. Michael Ruscio, DC is a clinician, Naturopathic Practitioner, clinical researcher, author, and adjunct professor at the University of Bridgeport. His work has been published in peer-reviewed medical journals and he speaks at conferences around the globe.
Leaky gut, also called “intestinal permeability”, is a loosening of the tight junctions between the cells that line your small intestine.
There are several diet and lifestyle factors, as well as infections that can increase digestive symptoms, intestinal permeability and leaky gut. These include inflammatory foods, alcohol, lack of sleep, stress, alcohol and NSAID (non-steroidal anti-inflammatory drugs) use, and antibiotics.
Leaky gut syndrome can cause a wide variety of symptoms across many different body systems.
If you have digestive disorders or gut health problems, you can generally assume that you have a leaky gut.
Though it’s unclear whether leaky gut is a cause or an effect health conditions, we do know that reducing intestinal permeability leads to symptom improvement.
Evidence suggests an association between leaky gut and some autoimmune diseases.
There are three main strategies to improve leaky gut: Diet changes, habit changes, and key supplements.
What is Leaky Gut?
Leaky gut, also called “intestinal permeability”, is a loosening of
the tight junctions between the cells
that line your small intestine.
Leaky gut is a big deal because it can lead to a litany of
chronic inflammatory conditions that cause pain, discomfort and disability. Leaky gut
symptoms often include mystery symptoms such as brain fog and joint pain.
Let’s look at this process in more detail:
The cells of your small intestine normally maintain a
barrier that allows only digested food molecules through.
When the tight junctions loosen, much larger molecules, such
food particles and bacterial fragments enter your bloodstream.
The immune system does not recognize these large
particles and launches an immune response.
This overzealous immune response leads to inflammation in
the gut and/or elsewhere in the body.
You may have heard of a protein called Zonulin. Zonulin
increases with bacterial overgrowths or gut infections and is currently the
only known biochemical driver of leaky gut. 
Though leaky gut syndrome is not yet recognized by the medical
community as a diagnosis, intestinal permeability is widely acknowledged in
permeability with a wide variety of health problems, including IBS, IBD,
diseases and Type 1 Diabetes.
What Causes Leaky Gut?
Diet and lifestyle factors can increase intestinal permeability and leaky gut symptoms.Gut infections are also a recognized cause.
Here is a summary of the most common causes of leaky gut:
Poor Diet and Inflammatory
Sugar, alcohol, and some processed foods generally increase inflammation and intestinal lining damage, or may feed bad gut bacteria, which can lead to increased gut damage and leaky gut. And though these foods are often inflammatory, any food that you have a food sensitivity or food allergy to can continue to encourage leaky gut.
Stress increases cortisol and other stress hormones which
can contribute to leaky gut. Chronic stress can make it difficult to resolve your
and other gut
health issues. [2, 3]
This includes chronic stress from over-exercising or over-training. 
A chronic lack of sleep (either poor sleep or too little
sleep) can impact your gut health and lead to intestinal permeability.
The use of antibiotics can negatively affect your beneficial
bacteria populations, which can lead to leaky gut, and can leave you vulnerable
to opportunistic infections. 
Alcohol, NSAIDs, and Prescription Medications
Regular alcohol consumption, use of NSAIDs (nonsteroidal
anti-inflammatory drugs) and aspirin, and some prescription medications have
been shown to increase intestinal permeability. [7,
Intestinal Dysbiosis and
Intestinal dysbiosis, whether from an overgrowth
of bacteria, or parasites or fungi, are a well-recognized contributor to leaky gut
by triggering the release of zonulin, and reducing the protective mucous layer in
the large or small
intestine. [10, 11, 12,
Symptoms of Leaky Gut
Leaky gut syndrome can cause a wide variety of symptoms across many
different body systems.
Digestive disorders, such as bloating, gas, gut pain, or frequent diarrhea or constipation are symptoms of leaky gut, and indicate leaky gut is present and needs to be addressed. There is also evidence that symptoms such as brain fog, joint pain, fatigue (especially after eating), and food sensitivities may be associated with leaky gut. Here is a summary of symptoms that may indicate you have leaky gut.
Lab tests for intestinal permeability measure zonulin
in blood or stool, or lactulose-to-mannitol ratio in urine. These lab tests
aren’t well validated in the research, although blood testing for zonulin
antibodies seems to provide some relevant information.
I generally don’t find these tests clinically valuable or to
be a good use of my patients’ health care dollars. If you have digestive
disorders or gut health problems,
you can generally assume that you have a leaky
As you work to heal your leaky gut, inflammation will reduce
and your symptoms will improve as well. That’s how you know your leaky gut is
What Does Science Say About Leaky Gut?
Leaky gut isn’t yet recognized as a distinct
condition in the scientific literature or by the medical community, but intestinal
permeability is widely researched. Despite the fact that leaky gut isn’t
a specifically defined condition, this doesn’t mean it’s not real and can’t be
Intestinal permeability has been documented in many
diseases such as celiac disease, inflammatory bowel disease (IBD), Type 1 Diabetes, food allergies,
bowel syndrome (IBS), Crohn’s disease, and even cardiovascular disease. [48,
51, 52, 53]
In celiac and Crohn’s disease, increased intestinal
permeability is associated with an increase in symptoms such as brain fog,
mood changes, skin lesions, chronic fatigue syndrome, and gut symptoms.
Most studies have been unable to tell which came first, the leaky gut
or the diagnosis. Though it’s unclear whether
leaky gut is a cause or an effect of health conditions, we do know that
reducing intestinal permeability
appears to lead to symptom improvements.
Is Leaky Gut the Cause of Autoimmune Diseases?
Many in the alternative medicine community claim that leaky gut
is the root cause of all autoimmune diseases.
While there is some evidence to suggest an association
between leaky gut and some autoimmune diseases, there is not yet enough
evidence to say all autoimmune disease is caused by leaky gut.
Some studies link certain autoimmune diseases like celiac disease,
disease, and rheumatoid arthritis with intestinal permeability.
In one study, Crohn’s disease patients and their close
relatives were evaluated for intestinal permeability. The relatives showed
evidence of intestinal
permeability, even though they were asymptomatic, indicating that leaky gut
may precede the development of Crohn’s intestinal symptoms.
In several animal studies, intestinal permeability was
shown to occur before the development of disease. [55,
More research is needed to fully understand these and
related phenomena. But the bottom line is that there is not currently enough
data to suggest that ALL autoimmune disease is caused by a leaky gut.
How to Improve Leaky Gut
Whether you have autoimmune disease, chronic inflammation, or annoying symptoms, there is plenty you can do to improve your gut health. Anything you do to improve your gut health will also help with leaky gut.
There are three main strategies to improve leaky gut:
If your skin reacts to a deodorant you’re using, you
wouldn’t go get a prescription for cortisone cream. You would find a different
deodorant that didn’t cause a reaction!
It’s much the same with diet. If you continue to eat foods
your body is sensitive to, you continue to create inflammation and irritation.
Improving your diet is one of the most important steps you can take for gut
There are several anti-inflammatory diets that could be a good leaky gut diet plan for you. The right one for you is the one your body responds to best. Here is a summary of the diets that have been shown to improve intestinal permeability:
How it Heals Leaky Gut
Decreases zonulin and FODMAPs.
Low FODMAP Diet
Decreased fermentable carbohydrates that may be irritating your gut by feeding gut bacteria.
Decreases processed foods, dairy, sugar, and carbs. Emphasizes a whole-foods, low-carb diet high in veggies, healthy fatty acids like coconut oil and avocado, and healthy protein.
Gives your gut a rest to decrease inflammation and allow healing.
Gives your gut a rest to decrease inflammation and allow healing.
Working with a nutritionist may help you find the right diet to use faster. You can read more about improving your diet for leaky gut in Leaky Gut Diet Plan.
Simple changes to your daily habits can significantly
gut. You don’t need to necessarily do ALL these things to experience a
benefit. Chances are there are one or two of these options that you know are
most out of balance.
Why It’s Important
Regular Moderate Exercise
Over-exercise can increase leaky gut [58, 59], while regular moderate exercise has been shown to decrease inflammation. 
Increase Nightly Hours of Sleep
Decreased sleep is associated with increased intestinal permeability. 
Improve Your Stress Management
Psychological stress has been shown to increase leaky gut. [62, 63]
Alcohol consumption can increase leaky gut. [64, 65]
Chew Your Food Well
Complete chewing decreases stress on your digestive system, and promotes more complete digestion.
Use Alternatives to NSAIDs and Aspirin
Several studies clearly demonstrate that NSAIDs and aspirin increase intestinal lining damage and leaky gut. [66, 67, 68]
Use Alternatives to Birth Control Pills for Contraception
Birth control pills may negatively affect the gut microbiome, and increase the risk for Inflammatory Bowel Disease (IBD) and other digestive problems. 
Probiotics improve the health of the gut microbiota and help to maintain a healthy intestinal barrier, while an overgrowth of bad gut flora or bacteria, such as SIBO (Small Intestinal Bacterial Overgrowth) can lead to increased intestinal permeability. [70, 71, 72, 73]
L-Glutamine is an amino acid that has a significant body of research showing its restorative properties for the gut lining, especially during stress. [74, 75]
Vitamin D seems to help maintain immune system balance in the gut and prevent gut health problems.
Other supplements, like digestive enzymes, prebiotics,
zinc carnosine, and more may be helpful, but may not be as necessary as probiotics,
and vitamin D.
Leaky gut, a loosening of the tight junctions between the cells of the small intestine, may sound a bit complicated. But the simple truth is that eating well, maintaining good health habits with sleep, stress, and exercise, and a few key supplements can begin to restore your intestinal wall barrier within a matter of weeks and can lead to rapid symptom improvement.
Though there isn’t yet enough evidence to claim that all
autoimmune diseases are caused by leaky gut, we do know that many medical
conditions and distressing symptoms can be improved by taking a few
simple steps to improve gut health.
I care about answering your questions and sharing my knowledge with you. Leave a comment or connect with me on social media asking any health question you may have and I just might incorporate it into our next listener questions podcast episode just for you!
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