An Overview of Leaky Gut Syndrome

Learn about this controversial condition

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Photo: Steve McAlister/Image Bank/Getty Images

Leaky gut syndrome, also known as increased intestinal permeability, is a controversial condition that has been linked with a variety of health problems, including skin rashes and mood disorders. The cause of increased intestinal permeability is not completely clear, but it may be associated with digestive conditions, including irritable bowel syndrome (IBS).

There is a test that has been used to diagnose the condition, but medical experts do not consider the test to be reliable. Dietary changes and supplements have been promoted as treatment strategies.

Because the condition is controversial, it is important that you seek reliable and safe information if you think that you may have increased intestinal permeability.


Proponents of leaky gut syndrome suggest that it could cause a number of digestive and systemic (whole-body) effects. The symptoms attributed to leaky gut syndrome may be present from a young age or can develop during adulthood.

The effects of leaky gut syndrome are often described as fluctuating, and these fluctuations may be associated with dietary or with other factors, such as stress, inflammation, infections, or environmental toxins.

Symptoms associated with leaky gut syndrome include:

  • Gastrointestinal (GI) problems: Abdominal discomfort, pain, gas, indigestion, constipation, bloating, diarrhea
  • Allergic and autoimmune reactions: Asthma, skin rashes, swelling
  • Joint and muscle issues: Chronic joint or muscle pain, fibromyalgia
  • Neuropsychiatric conditions: Memory problems, mood swings, agitation
  • Infections: Frequent respiratory infections, vaginal infections, recurrent bladder infections

Leaky gut syndrome has also been proposed as a cause of acne, psoriasis, and chronic fatigue syndrome.

In general, advocates of leaky gut syndrome awareness suggest that each individual who has the condition may experience some, but not necessarily all of these symptoms.


Among the most controversial issues regarding the topic of leaky gut syndrome is a proposed association with autism. Proponents of this theory suggest that increased intestinal permeability could be a possible cause of inflammation in the brain—resulting in autism.

However, while this is a widely promoted concept on social media, medical organizations such as the American Medical Association (AMA) have not accepted the scientific validity of this proposed association and do not support the use of unapproved leaky gut syndrome treatments for the management of autism.


Leaky gut syndrome has been linked to several risk factors. The theory is that certain health conditions cause the intestines to leak material into the body, resulting in the GI and systemic effects attributed to leaky gut syndrome.

Some factors that have been suggested as causes of leaky gut syndrome include:

  • GI Infections
  • Inflammatory bowel disease (IBD)
  • Stress
  • Alcohol
  • Diet
  • Bacterial imbalance in the GI system
  • Medications
    Environmental toxins

Tight Junction Instability

Nutrients are normally absorbed into the body through the capillaries (tiny blood vessels) of the digestive system. The digestive system is lined with cells that are attached together by tight junctions. The cells and their junctions do not allow materials to freely flow into the body.

It has been proposed that bacterial overgrowth or the other factors associated with leaky gut syndrome could interfere with the structure and function of the tight junctions in the intestines.

The idea behind leaky gut syndrome is that if the tight junctions in the intestines become altered or damaged, it could result in increased permeability (leakiness) of the intestines.

Inflammatory Response

With increased intestinal permeability, it is proposed that molecular substances, including environmental toxins, may be able to flow from the digestive system directly into the body.

It is suggested that these molecules may trigger an immune system response. It is this inflammatory response that is thought to play a role in the various health effects associated with increased intestinal permeability, such as the rash, joint pain, and mood problems.

Researchers aren't sure whether conditions such as infections and IBD could cause increased intestinal permeability or whether the increased intestinal permeability could be responsible for IBD and a predisposition to infections.


If you have symptoms that are associated with leaky gut syndrome, your doctor will take a careful medical history and perform a physical examination. Because the symptoms associated with leaky gut syndrome are common in other medical conditions, a number of diagnostic tests may be needed.

Diagnostic tests are generally guided by your symptoms and physical examination. For example, if you have joint swelling or pain, your doctor may order blood tests to look for inflammation. If you have digestive complaints, you might need an imaging test, such as an abdominal ultrasound.

Leaky gut syndrome is typically considered after other medical conditions are ruled out.

Urine Test

A urine test has been used to help in the diagnosis of increased intestinal permeability.

You would start by drinking a solution that contains "probe molecules"—typically mannitol and lactulose. Urine samples are taken at intervals following the ingestion of the solution, and a ratio of lactulose and mannitol is calculated. If there are high levels of both molecules, increased permeability is thought to be present.

It is important to note that this test is not considered to be consistently reliable and might not reflect whether you have increased intestinal permeability or not.

The diagnosis of leaky gut syndrome, like the condition itself, is controversial. Some practitioners suggest that the diagnosis is made if symptoms improve with dietary changes, including probiotic supplements.


The medical management of leaky gut syndrome is fairly new. Dietary strategies are aimed at changing the intestinal bacteria, often with the aid of probiotics. Medications, including anti-inflammatory medications and antibiotics, have been proposed as possible approaches to decrease intestinal permeability and/or improve symptoms of leaky gut syndrome.


The dietary approaches that are often suggested for the management of leaky gut syndrome vary. Some dietary strategies focus on eating fresh fruits and vegetables to reduce inflammation in the intestines. Gluten-free diets have been suggested as well, particularly when there is also a diagnosis of celiac disease.


Probiotics are foods or supplements that are often used to help balance the bacteria in the intestines. Several types of yogurt contain probiotics.


There are many companies that sell supplements directly to consumers, often through direct mail order or through online representatives or salespeople. While such supplements can be safe, doctors and medical organizations warn about the safety of using products aimed at treating leaky gut syndrome.


There are several different medical approaches that have been used for the treatment of increased intestinal permeability, but there is no definitive cure or medication that has been proven effective. Anti-inflammatory medications, including steroids, have been proposed as a possible treatment, as have antibiotics.

Lubiprostone, which is approved for the treatment of constipation, was shown to reduce the lactulose-mannitol ratio in a small study, but it did not change symptoms.

A Word From Verywell

Leaky gut syndrome is gaining widespread popularity in the mainstream media. The research regarding this syndrome is scant and inconsistent, however, and the medical community has been cautious in accepting this diagnosis.

Certainly, many medical theories turn out to be true after extensive study, and many theories are disproven after years of careful research. Leaky gut syndrome is still a fairly new concept that will likely be examined more extensively in the coming years.

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Article Sources

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  3. AMA Journal of Ethics April 2015, Volume 17, Number 4: 369-374 SECOND THOUGHTS Complementary and Alternative Treatments for Autism Part 1: EvidenceSupported Treatments Stephen Bent, MD, and Robert L. Hendren, DO

  4. Mu Q, Kirby J, Reilly CM, Luo XM.Leaky Gut As a Danger Signal for Autoimmune Diseases.Front Immunol. 2017 May 23;8:598. doi: 10.3389/fimmu.2017.00598. eCollection 2017.

  5. Kato T, Honda Y, Kurita Y, Iwasaki A, Sato T, Kessoku T, et al. Lubiprostone improves intestinal permeability in humans, a novel therapy for the leaky gut: A prospective randomized pilot study in healthy volunteers.PLoS One. 2017 Apr 14;12(4):e0175626. doi: 10.1371/journal.pone.0175626. eCollection 2017.

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