leaky gut syndrome

Is leaky gut syndrome real? Here’s what you need to know about this condition, how it affects your body, and how to heal for good.

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What is Leaky Gut Syndrome?

Think about your digestive system for a second — from mouth to anus, it’s really just one long tube that dictates what can be absorbed into your bloodstream and what passes through the body. It knows that things like nutrients and water are important to absorb into the bloodstream, while toxic particles and undigested foods should make their way to the large intestine to be passed out of the body in the form of stool.

The gut barrier is one single cell layer thick and is connected by “tight junctions” that hold the cells together. This single layer of cells and the tight junctions between them are the only things preventing harmful particles from entering your bloodstream.

When the gut is functioning normally, these tight junctions hold the cells that make up your gut barrier together and only allow small particles (like nutrients) into the bloodstream.

Leaky gut syndrome, or increased “intestinal permeability,” is when the tight junctions holding the cells of your gut barrier together don’t function properly and the cells drift apart, allowing larger molecules like bacteria, undigested food particles, and waste products into the bloodstream.

Think of the gut barrier like a strainer. It only lets things of a certain size pass through, while anything too big will be kept out. Now imagine the holes in your strainer getting bigger, thus allowing larger particles through. That’s exactly what’s happening to your gut when you have leaky gut syndrome.

When you have leaky gut, your body is bombarded with unrecognized particles like lipopolysaccharides (LPS) that are present on the outer membrane of bad bacteria as they make their way through the bloodstream. Your immune system goes into high alert to try to protect you from these toxic particles, and as a result, you develop a high amount of inflammation.

This high level of LPS in the blood is associated with many conditions, as you can see below.

Rodriguez-Castaño GP, Caro-Quintero A, Reyes A, Lizcano F. Advances in Gut Microbiome Research, Opening New Strategies to Cope with a Western Lifestyle. Frontiers in Genetics. 2016;7:224. doi:10.3389/fgene.2016.00224.

I’ve written more about microbial imbalance and the resulting inflammation, and how that contributes to disease (specifically metabolic disease) in this article.

Is Leaky Gut Real?

There’s a lot of controversy over the term “leaky gut,” particularly the use of the term “leaky gut syndrome,” which seems to indicate that this condition is an official medical diagnosis.

Leaky gut syndrome is not a medical diagnosis, however, leaky gut is indeed a very real phenomenon that is seen throughout the scientific literature. Leaky gut is simply the more colloquial term for increased “intestinal permeability” or “intestinal hyperpermeability,” which are the terms you’ll see most often in the scientific research. (Though the term “leaky gut” is even catching on in research, and you’ll see that now too!)

In fact, at the time of this posting, there are over 90,000 Google Scholar results for the term “intestinal permeability”, and as you’ll see throughout the rest of this article, intestinal permeability is associated with a vast array of diseases and conditions.

What Causes Leaky Gut?

While there’s a lot we’re still learning about leaky gut, there are a few things we know of already that can cause this syndrome.

Gut Microbiome Imbalance (Dysbiosis)

Having an overload of bad gut bacteria (or dysbiosis) is one of the top causes of leaky gut syndrome. That’s because these bad bacteria have a toxic molecule on their outer membrane called lipopolysaccharide (LPS) that is highly inflammatory.

LPS causes gut inflammation, which causes the cells of the gut barrier to pull further apart, leading to leaky gut syndrome.

When you have both leaky gut and dysbiosis, the LPS that causes leaky gut then gets into the bloodstream, taking inflammation to the rest of your body and putting your immune system on high alert.

You can read more about dysbiosis and how it contributes to leaky gut and other diseases here.


Stress is also a huge factor when it comes to leaky gut syndrome. Researchers have known for a long time that severe physical stress such as trauma or surgery causes the intestinal lining to become “leaky”, but more recent research has started to look at the effect of chronic psychological stress on the gut barrier.

To approximate chronic psychological stress in humans, rats are repeatedly subjected to water aversion stress where they are placed on a platform surrounded by water. Researchers have found that this is a mild stressor to the rats, similar to the type of chronic mild stressors we face today. So what happens to these rats? They develop intestinal permeability that takes several days of no stress to heal.

This mild, chronic stress directly causes the cells of the gut barrier to drift apart, which, as discussed earlier, allows toxic particles to filter through into the bloodstream.

In addition to this, stress also imbalances gut bacteria, which also leads to the development of leaky gut syndrome in and of itself.

Certain Pharmaceutical Drugs/Alcohol

Certain drugs like NSAIDs (e.g. aspirin and ibuprofen, among others) are known to cause leaky gut. Alcohol also has the same effect.

However, it should be noted that it is chronic, excessive use of these items that leads to major intestinal permeability, so don’t worry if you like to enjoy a glass of wine or need to take an aspirin every once in a while!

That said, if you’re actively trying to heal from leaky gut (and not just trying to prevent it), it’s a good idea to limit your alcohol intake and avoid using NSAIDs as much as possible.


Diet plays a very important role in digestive health. An unhealthy diet, high in sugars and unhealthy fats while low in fiber, can lead to the development of leaky gut syndrome. This is because an unhealthy diet encourages the growth of bad gut bacteria. Unfortunately, this is common on a Standard American Diet (SAD).

In addition to eating unhealthily, consuming foods that you are allergic or sensitive to can also lead to irritation and inflammation in the gut and intestinal permeability.

Leaky Gut Symptoms

According to the scientific literature, there are a number of conditions that are associated with increased intestinal permeability, both within the digestive system as well as outside of it.

These conditions include:

    • Ulcers
    • Diarrhea
    • Irritable bowel syndrome (IBS)
    • Inflammatory bowel diseases (IBD — ulcerative colitis and Crohn’s disease)
    • Celiac disease
    • Cancer, esophageal and bowel
    • Allergies
    • Infections
    • Acute inflammation
    • Chronic inflammation
  • Obesity-associated metabolic disease

Now, this does not necessarily mean that leaky gut itself causes these conditions, just that intestinal permeability is commonly seen in these conditions.

However, there is research that indicates that leaky gut is present before the development of disease which makes researchers believe that it may be a “requirement” of sorts to develop various diseases.

However, it has given researchers a lot to think about as they explore leaky gut treatment possibilities to help prevent, treat, or reverse some of these conditions. I, for one, am very excited to see where the science leads us.

Testing for Leaky Gut

Leaky Gut Tests on the Market

There are two common tests for identifying leaky gut: differential sugar tests (like the lactulose mannitol test) and the zonulin test.

Differential sugar tests (DSTs) are considered the “gold standard” in leaky gut testing. For this test, you drink a solution containing specific sugars and then the levels of these sugars are measured a few hours later in your blood or urine. The idea here is that large oligosaccharides, like lactulose, do not pass through the gut barrier, while small monosaccharides, like mannitol, do. By testing for the sugars in the bloodstream or urine after consuming them, you’re able to see the degree of intestinal permeability that is present.

Testing for zonulin in the blood is, unfortunately, not a great way to determine if you have leaky gut. Zonulin levels do not seem to correlate with other markers of intestinal permeability (like the DSTs mention above), and zonulin levels are constantly changing, making one single measurement of this protein a fairly useless measurement of intestinal permeability.

Testing for zonulin antibodies, on the other hand, may prove a more useful measurement.

If you want to test for leaky gut, a differential sugar test or a zonulin antibody test is your best bet.

But that brings us to our next question… Is testing for leaky gut even worth it?

Is it Worth Testing for Leaky Gut?

I’m going to cut right to the chase here and say… No.

I’m not a big fan of testing for leaky gut because it never changes how we’re going to address it.

Truth is, there’s always something else causing leaky gut, like bad gut bacteria (dysbiosis), a poor diet, stress, food intolerances, etc.

So I’d much rather test for or evaluate those areas of my client’s lives than test for leaky gut.

Because, really, if I see someone who has digestive issues or an autoimmune disease or any of the conditions I mentioned above that are associated with leaky gut, I’m 99% sure that they have leaky gut anyway. I don’t necessarily need a test to tell me that because it’s not going to change how I approach the situation.

Instead of testing for the “symptom” (leaky gut), you want to test for the root cause (gut bacteria, stress, diet quality). Because when I know that a client has dysbiosis and their diet isn’t great and they have a stressful job, addressing all of those things is what is going to heal their leaky gut.

Save your money for gut bacteria testing instead of spending it on leaky gut tests!

Healing Leaky Gut

Now, just because testing for leaky gut is somewhat pointless doesn’t mean you shouldn’t treat leaky gut. As I hope you realize by now, leaky gut is indeed a real phenomenon that is important to address.

You may have heard that you can take supplements alone to heal leaky gut, but the crux of a leaky gut syndrome treatment plan tackles gut microbial imbalance, diet, and stress (with supplements to help along the way).

Leaky Gut Treatment Plan

The Leaky Gut Cure: Balancing Your Microbiome

The #1 cause of leaky gut is an imbalanced microbiome (dysbiosis). It is absolutely vital that you determine if you have bad gut bacteria and balance your microbiome if you want to cure leaky gut.

If you find you have imbalanced gut bacteria through SIBO testing or stool testing, you must get rid of that bad bacteria in order to heal leaky gut.

This is done by using herbal or pharmaceutical antimicrobials, dietary changes, stress reduction, and more. You can read more about how to get rid of bad bacteria here.

If you want to learn more about bacterial imbalance and how to fix it, I encourage you to take my free training by clicking the image below!

leaky gut syndrome

Leaky Gut Diet

As mentioned previously, a Standard American Diet full of unhealthy fats and sugars and low in fiber is a recipe for disaster when it comes to leaky gut.

Researchers are also worried about the impact of processed food additives, like emulsifiers and solvents, on our gut barrier, so avoiding processed foods is a good idea.

The best thing you can do from a dietary perspective to heal leaky gut is to eat an organic, nutrient-dense, whole foods diet that is high in fiber and prebiotics and low in unhealthy fats and sugars. You can read more about my dietary philosophy when it comes to supporting a healthy gut here.

The best foods to heal leaky gut include:

    • Non-starchy vegetables (broccoli, cabbage, leafy greens, etc)
    • Starchy vegetables (potatoes, sweet potatoes, yucca, taro, squash, etc)
    • Fruits (bananas, oranges, berries, apples, etc)
    • Meats (beef, pork, chicken, duck, etc)
    • Seafood (oysters, scallops, shrimp, sardines, etc)
    • Healthy fats (Olive oil, avocado oil, animal fats, etc)
    • Nuts (walnuts, macadamias, almonds, etc)
    • Legumes (if tolerated — lentils, beans, chickpeas, etc)
  • Dairy (if tolerated — yogurt, cheese, etc)

As much as possible, choose organic foods to avoid pesticides and additives. When trying to heal from leaky gut, it’s also wise to limit the amount of alcohol you consume.

Repair a Leaky Gut with Stress Management

Chronic stress induces intestinal permeability, so it’s imperative on any leaky gut treatment plan to incorporate stress management techniques.

Deep breathing, meditation, chi gong, yoga and more are options, but really, any stress management technique that you enjoy and are likely to do on a regular basis is best!

I find that my clients benefit more from practicing these techniques for shorter periods of time more often (for example, 5-7x/week) than doing a long session, say, once a week.

Best Supplements for Leaky Gut

There is a lot of really promising research looking at the best supplements for leaky gut, but it’s important to remember that supplements do not negate the need to address things like dysbiosis, diet, and stress.

You can take a million supplements for leaky gut, but if you’re not addressing those main causes of intestinal permeability, supplements really won’t get you very far. As much as I would love to tell you otherwise, there is no magic pill.

Supplements are used to “supplement” an existing treatment plan; they can help speed up the process of healing or make it easier, but they themselves won’t cause any lasting change on their own.

Antimicrobials Kill off Bad Gut Bacteria

It is clear that imbalanced gut bacteria, or dysbiosis, plays an enormous role in the development of leaky gut.

Because of that, it’s absolutely necessary to kill off bad bacteria and encourage healthy growth of beneficial microbes.

Most often, getting rid of bad bacteria is going to require being on antimicrobials of some kind (whether they are herbal or pharmaceutical).

As a dietitian, I’m a big fan of herbal antimicrobials. Here are some of my favorites to use:

    • Oregano oil (found in Biotics Research ADP — I like this one in particular because it’s a time-released oregano supplement)

Probiotics for Leaky Gut

Probiotics, in general, have proven to be very helpful in restoring and maintaining proper gut barrier integrity.

However, we need to remember that probiotic effects are strain-specific, so it’s important to pay attention to the exact strains that have been shown to be helpful (so that if you buy a probiotic to take, you know you’re getting a strain that actually has been proven to improve leaky gut!).

Here are the best probiotics for leaky gut:

Prebiotics for SCFA Production

Prebiotics are a powerhouse when it comes to healing leaky gut. It has been shown that supplementing with prebiotics reduces LPS concentrations in the blood. Remember that LPS is the toxic molecule on the outer membranes of bad gut bacteria. When you have a permeable gut, more of this toxic particle gets into your bloodstream and wreaks havoc from there. So when researchers are trying to determine whether a substance reduces leaky gut or not, they can look at the amount of LPS that ends up in your blood.

Now, prebiotics are different from probiotics. You can think of prebiotics as the food or fuel for probiotics; in essence, they feed your good bacteria so that you have plenty of the good guys around.

In addition to this, prebiotics also increase your production of short-chain fatty acids (SCFAs) which help to heal and seal the gut barrier as well as reduce inflammation (since less inflammatory LPS particles are getting through to the bloodstream).

My favorite prebiotics include:

A quick note about the Sunfiber supplement is that, unlike other prebiotics like GOS or FOS, Sunfiber is low-FODMAP and thus does not tend to increase digestive symptoms like bloating or gas like higher-FODMAP choices do. It also mixes really easily with water or other liquids, so it’s super easy to take.

Quercetin Seals a Leaky Gut

Quercetin is a really useful tool for helping to heal leaky gut. In fact, I’ve written a whole article on the topic!

We’ve already discussed the fact that stress increases intestinal permeability. Part of how this happens is that stress “destabilizes” or “degranulates” mast cells.

You may have heard of mast cells before as the cells responsible for allergy symptoms, like congestion, runny nose, etc. This is because when mast cells “degranulate” or become “unstabilized,” they release histamine, the chemical that causes allergy symptoms.

But you have mast cells all throughout your gut too, and when they “degranulate” or become “unstabilized” there, they cause leaky gut.

So how does quercetin fit into the picture?

Quercetin is one of the most abundant flavonoids present in our food supply, found in high amounts in onions, kale, and apples. It is well-known for many things, including its anti-allergy properties, anti-cancer effects, and as an antioxidant. But did you know that it can heal leaky gut too?

Since intestinal permeability is caused (at least in part) by unstabilized mast cells in the gut, it makes sense that quercetin would have this effect. This is because quercetin stabilizes mast cells and prevents the release of histamine and other chemicals from these cells. When researchers breed rats to have no mast cells in the gut (thus they are unable to have unstabilized mast cells that release histamine), they no longer develop intestinal permeability.

Quercetin has also been shown to enhance gut barrier function by having a “sealing” effect due to its role in the assembly and expression of tight junction proteins. Tight junctions regulate our intestinal permeability by connecting intestinal cells, thus only allowing the nutrients that we need in and keeping everything else out.

As you can see, adding quercetin to your leaky gut supplement protocol can really do a lot to help keep that gut barrier sealed up!

There are plenty of quercetin supplements on the market, but one of my favorites is the Source Naturals Activated Quercetin supplement.

Collagen Repairs a Leaky Gut

Collagen is the most abundant protein in our body, and is found in high amounts in the gut. It is also a potent source of the amino acid glycine.

As humans, we are meant to eat a mix of both glycine and methionine (among other amino acids), but in the modern world where we don’t tend to eat nose-to-tail, that can be difficult. You see, glycine is abundant in animal products that we don’t usually consume, like tendons, ligaments, and bone while methionine is present in high amounts in muscle meat (think steak, chicken breast, etc). This altered ratio of methionine:glycine intake is thought to be related to our increase in chronic disease rates. I highly recommend watching Denise Minger’s Ancestral Health Symposium talk on this topic.

Because of its role in the gut, collagen peptides have been found to heal leaky gut by improving tight junction function.

There are many collagen peptide supplements on the market right now, but I’m a big fan of the Vital Proteins line.

L-Glutamine Fuels Gut Cells

Glutamine is an amino acid and is a major fuel source for intestinal cells.

It has been studied and used for years in relation to its ability to reduce intestinal permeability in critically ill patients.

In addition to this, glutamine supplementation can also improve gut bacteria balance.

This gives you a great combination of benefits: glutamine balances your microbiome and heals leaky gut.

While capsules may seem like the easiest to take, you’re actually better off getting a powder for supplementation. This is because you’re generally going to want fairly high doses of glutamine to get the benefits for leaky gut.

In healthy adults, the observed safe level of l-glutamine is 14g/day. Considering that most capsules contain a maximum of about 1000mg, you’d have to take 14 of them every day!

Therefore, an L-glutamine powder is a much better choice for leaky gut.

Vitamin D Keeps Your Gut Healthy

Vitamin D is one of those vitamins that you sit and wonder… “What can’t Vitamin D help with?!”

From bone health to the immune system, Vitamin D plays a role in almost every facet of our being — and that includes preventing and healing leaky gut.

You see, Vitamin D deficiency makes you more likely to have leaky gut. The good news, however, is that supplementing with Vitamin D can keep your gut barrier in good condition.

You can get Vitamin D from sun exposure, food, and supplementation. Getting proper sun exposure is the best way to get your Vitamin D, of course! There are very few foods that contain a lot of Vitamin D, so it’s somewhat difficult to get your D from your diet.

If you’re not getting enough sun exposure to get adequate Vitamin D, your next best bet is to supplement.

I recommend taking a Vitamin D3 supplement. Depending on your current blood levels, taking anywhere from 2000 – 5000 IU per day is a good idea.

And because fat-soluble vitamins work synergistically, I recommend taking a combination supplement that also includes Vitamin K2, like Thorne’s Vitamin D/K2 Liquid.

Zinc Improves Gut Barrier Integrity

Zinc is an important mineral that is used in a variety of processes within the body to keep us healthy.

When you’re deficient in zinc, your body’s ability to heal wounds may become impaired, your immune system may not function as well, and you might develop anemia, hypogonadism, or mental illness.

In addition to this, your gut barrier may become impaired. Zinc supplementation has been shown to improve gut barrier integrity in those with Crohn’s disease. It does this by strengthening the tight junctions that hold the cells of the gut barrier together.

I like to incorporate zinc into any leaky gut supplement protocol for these reasons. Zinc carnosine is my favorite form of zinc for leaky gut as it’s been shown to heal leaky gut and help repair gut cells.

I like Integrative Therapeutics’ Zinc Carnosine supplement.

How Long Does It Take to Heal Leaky Gut?

As I mentioned before, treating leaky gut requires a multi-pronged approach. You need to get rid of bad gut bacteria, manage your stress, and eat well. Supplements can help you do these things, but they’re not the end-all-be-all of leaky gut treatment.

When people ask this question, what they really mean is “How long will it take before I feel better?” That can really depend.

If you have an autoimmune disease and believe leaky gut is playing a role in that, the truth is you may never fully recover from autoimmunity. That said, healing your gut can improve your symptoms immensely. I’ve seen symptom improvement in as little as a month, while others can take 6 or more months to really see significant benefits.

If you have digestive issues that you think are caused by leaky gut, I’ve found that healing your gut goes a long way toward recovery. Just as with autoimmune diseases, I’ve seen significant improvement in as little as a month when really addressing all aspects of a leaky gut treatment plan.

When it comes down to it, how long it will take you to heal leaky gut totally depends. It depends on how long you’ve been dealing with gut issues, how much you’re able to commit to the changes that need to be made to heal your gut, and then it’s just about how your body (we’re all different, right?) responds.

The short answer: on average it can take anywhere from 1-6 months to actually feel better when you’re trying to heal from leaky gut (though it may take longer for your gut barrier to completely repair).

Heal Leaky Gut For Good

While I hope this article has given you a lot to start thinking about, if you want to learn exactly how to address digestive issues, I’d like to invite you to join my free training.

You’ll learn:

    • How to fix digestive issues even if you feel like you’ve tried everything before
    • How to determine the cause of digestive issues and heal them for good
  • How to overcome food sensitivities

I’ll go into more detail on the gut bacteria imbalances that cause leaky gut (remember you have to get rid of those bad guys if you ever want to heal leaky gut!).

Want to join me? Click the image below to sign up!

leaky gut syndrome

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