Is Leaky Gut Real? The Hard-to-Believe Bizarre Truth

is leaky gut real

Is Leaky Gut Real?

Let me start out by clarifying that, whether or not leaky gut is real, it’s not currently an official diagnosis.  

If you go to your general practitioner and ask about it you may get some skeptical looks.  That doesn’t necessarily mean that leaky gut syndrome is nonsense, though.

Research has begun to delve more deeply into how the lining of your gut works. It looks like its ability to let molecules in and out (its “permeability” or “leakiness”) does indeed have to be very tightly regulated.  There is evidence that imbalances, particularly excessive leakiness, are bad for your health.

Your Gut

Your intestines are one of the most important parts of your GI tract.  Your GI tract is one long tube that extends from your mouth all the way to the other end. It begins breaking down food as soon as you take a bite.  

Eventually, food is broken down into tiny components that can pass through the walls of your GI tract.  Once through your gut wall, they pass into your bloodstream and then out into all the cells of your body.

One of the biggest responsibilities of your gut is pretty obvious – to get nutrients from your food into your body. A lesser known function is to keep bad stuff, like bacteria and environmental toxins, out of your bloodstream.

In order for that to happen correctly, the lining of your gut needs to be somewhat permeable.  Some things need to be able to pass through it, but definitely not everything.

Your small intestines do the majority of the nutrient absorption legwork so you want to have intestinal permeability there.  

Your large intestines are responsible only for the absorption of water and a few vitamins and minerals. They are less permeable than your small intestines by design.  They also house your gut bacteria, which have their own important roles in digestion and keeping your GI tract healthy.

The Science Behind Healthy Intestinal Permeability

To better understand what makes leaky gut real, it’s helpful for you to understand the basic anatomy of your intestinal wall.

Villi and Microvilli

If you were playing Red Rover, your brush border would be the line of kids calling you over.  They get to decide if you can break through their chain or if you get sent back.

You already know your GI tract is one long tube – it’s about 15 feet long.  That’s already pretty long, but the surface area of your intestines is increased by small, fingerlike projections called villi and microvilli. They extend into the tube (intestinal lumen) to allow for more surface area capable of absorbing nutrients.

Villi are only about 1 millimeter in height and microvilli are even smaller. So, while the inside of your intestines won’t look like they’re shag carpeted, they probably look a little fuzzy.

The microvilli create what’s called the brush border.  This is where the last steps of digestion take place, resulting in tiny nutrients your body can absorb.  

If you were playing Red Rover, your brush border would be the line of kids calling you over.  They get to decide if you can break through their chain or if you get sent back.

Tight Junctions

In order for that Red Rover chain to keep dangerous molecules out, it needs to be strong and well-connected.  Wisely named “tight junctions” make up the connections between each cell of the brush border.  

When working correctly, they sit tightly together but can open up and become a gateway for nutrients to be absorbed.  If your brush border is damaged or weakened, however, those tight junctions aren’t so tight. Small gaps open up between the cells.

These small spaces can allow bacteria, toxins and other unwanted materials to break through the brush border, into your body.

Most of this process takes place in the small intestines, where nearly all nutrients are absorbed.  What’s left of your food moves into your large intestines.

The Large Intestine and Your Gut Bacteria

In your large intestine, those good bacteria I mentioned go to work!  They break down fibers and starches your body can’t digest, freeing up some vitamins and fatty acids your small intestines couldn’t get to on their own.

Water is also absorbed at this point.  This is a process that requires good balance and regulation.  Too much water absorbed can mean constipation, while too little means diarrhea.


Since there are some nutrients absorbed through your large intestines, there need to be healthy cells lining those walls as well.

Your large intestines don’t have such pronounced villi, but they do have a huge population of bacteria that help keep your intestinal walls healthy and tight.  The good bacteria you naturally have in your body make sure any bad bacteria you might acquire are a minority in the large intestinal population.

When things like stress, a poor diet, and antibiotic use creep into your life, your good gut bacteria can become outnumbered. This allows for the weakening of your intestinal lining and potential breakthrough of those bad bacteria into your bloodstream.  

This can result in physical symptoms like abdominal pain, bloating, constipation or diarrhea, food intolerances, skin conditions, and brain fog.

When Intestinal Permeability Becomes Unhealthy

Like every important process in your body, intestinal permeability can get out of whack. Researchers think there are several ways this can happen!

Inadequate Nutrition

One of the ways these cells of your intestinal wall stay strengthened is through adequate nutrition.  The enzymes involved in digestion actually partially break down the cells responsible for nutrient absorption. 

That means these cells have a short lifespan.  In fact, you need to replace them every two to five days!

High turnover means the absorption system is very sensitive and can be easily damaged, especially by undernutrition.  

If you’re not getting enough nutrition, your body isn’t fueled well enough to create more of those cells to replace the ones being digested in the absorption process.

You’ve only got about five days at the most before your supply starts declining.  So, you need to make sure you’re fueling up well.

Unhealthy Gut Bacteria

In diseases ranging from eczema to diabetes, there is evidence of fewer or less active good bacteria in the gut and an increase in gut leakiness.

You may have heard about probiotics and how important they are for gut health.  One of the reasons why is that those good bacteria, as probiotics are often described, help maintain the barrier function of your intestinal lining.

As I mentioned above, good bacteria work together with your body to keep your intestinal wall in good working order.  In diseases ranging from eczema to diabetes, there is evidence of fewer or less active good bacteria in the gut and an increase in gut leakiness.

How can the populations of good bacteria in your gut get messed up and cause a leaky gut?

It seems there are a lot of factors at play, but high stress levels, chronic diseases, antibiotic use, and eating an unhealthy diet high in fat and/or sugar are thought to be particularly good at messing with the health of your gut bacteria.

Environmental and Lifestyle Stressors

Evidence also suggests that overall emotional stress, NSAIDs (pain medicines like Ibuprofen and Advil), and chronic inflammation can weaken the lining of your intestines and damage your gut.

How Would You Know If You Have a Leaky Gut?

Because our intestines should be somewhat permeable, you could argue that everyone has a leaky gut.  The real question then may be, is my gut too leaky?

So, how would you know if your gut is too leaky?

A too leaky gut can manifest in a number of ways.

The most common leaky gut symptoms are GI issues, such as gastric ulcers, inflammatory bowel diseases (IBD) like Crohn’s and Celiac disease or inflammatory bowel syndrome (IBS).

Your gut may also be leaky if you have conditions you wouldn’t necessarily relate to your intestines.  Allergies, chronic inflammation, cancer, infections, obesity and obesity-related diseases (like diabetes or fatty liver) can be clues that your gut has become too leaky.

You can also have a leaky gut because of other illnesses and conditions.  Serious diseases or malnutrition, for example, can greatly impact and impair your gut integrity.  So, receiving a chronic illness diagnosis may be a tip-off your gut health is in danger.

How Do You Test for Leaky Gut?

Truly determining if your current symptoms indicate you could have a leaky gut is a tricky topic.  

Remember when I mentioned that leaky gut syndrome is not an official diagnosis?  

That means you likely won’t be able to go to your doctor and get a run-of-the-mill test and a yay or nay on your diagnosis.

That said, there are a few tests that can see if your gut is leaky.

Learn More: The Best Microbiome Testing Companies: Gut Testing Made Easy

Leaky Gut Urine Test

The most popular leaky gut test is a urine test spanning five hours.  Samples collected over all five hours are screed for the presence of two different substances – lactulose and mannitol – which you are given mixed in a drink at the beginning of the test. 

By examining how much of these substances make it into your urine, your doctor can tell how easily stuff is making it through your gut wall.  While this test is most widely used in screening for Celiac disease, it can also be used for those concerned about the leakiness of their gut, in general.

Then again, if you don’t have classic symptoms of celiac disease it may be hard to convince your doctor you need this more extensive testing method.

Treating a Leaky Gut (With or Without a Diagnosis)

Many natural health practitioners suggest that having some or all of the symptoms we’ve discussed is enough to determine your leaky gut is real and that specific testing would only waste money figuring out something you already know.  

They usually recommend simply making dietary and lifestyle changes that will help promote gut healing without worrying about tests.

Dietary and Lifestyle Changes

Dietary and lifestyle changes may be all it takes to heal your leaky gut syndrome.  

By avoiding things like cigarette smoke and a sedentary lifestyle, and adding things to your diet like fruits, vegetables, and whole grains, you can make drastic improvements to the health of your GI system.

That’s funny – isn’t that the same advice you get for most health concerns?  

It is!  

You don’t have to reinvent the wheel here or try tons of products that may or may not deliver results.  Simple changes to your diet – that you probably already know are good ideas – may be all you need.

Leaky Gut Supplements

If after dietary and lifestyle changes you’re still not feeling 100%, or if you’ve noticed improvements and want to take things a step further, there are some likely beneficial leaky gut supplements you could try.  

Again, most of these probably won’t shock you.  Probiotic supplements, fiber, omega-3s – these are fairly conventional supplements that both conventional and naturopathic practitioners agree provide health benefits.

Related: Top 5 Best Butyrate Supplements for Leaky Gut Cure

It’s important to remember, though, that the FDA does not regulate supplements.  So, be mindful of where you buy them.  In fact, it’s probably a good idea to buy ones an independent third party has tested to verify they contain what they say they contain.

And keep in mind that you should use supplements as just that – supplements.  

Any supplements you choose to take should not replace the vitamins, minerals, fiber, and healthy fats you get from eating fruits, vegetables, whole grains, nuts, seeds, lean meats, and fatty fish.

Is Leaky Gut Serious?

The seriousness of leaky gut syndrome will depend on the severity of your symptoms and your current diet and lifestyle.

Earlier I mentioned that all of us have some degree of intestinal permeability because that’s how our bodies work to absorb nutrients.  

If you eat lots of fruits, vegetables, whole grains, and include some fermented foods (a natural source of probiotics) every day, your GI tract is likely the appropriate level of permeable.

On the other hand, if your diet falls more on the high fat or high sugar end of the spectrum and you rarely get the recommended amount of fruits (at least 5 servings per day), your GI tract may not be as healthy and strong as you’d like it to be. 

And if your daily life is full of stress or you often find yourself inactive, your body and your gut bacteria may not be getting the rest and exercise needed to keep them strong and healthy.  There would be an even stronger case for your gut being unhealthy if you have symptoms like fatigue, constipation or diarrhea, gas, or abdominal cramping.

In the short term, this imbalanced gut environment may cause these GI issues, and maybe some skin conditions or higher risk of colds and flu (since your gut is an active part of your immune system).  

The seriousness of leaky gut syndrome increases the longer it goes unaddressed, though.  

Since gut health contributes to immune health, a leaky gut may put you at risk of developing illnesses ranging from heart disease to cancer.  It may also lead to chronic inflammation, which is suspected to contribute to diseases like arthritis, diabetes, and dementia.

Take Home Message

Is leaky gut real?  

Yes, your intestines allow nutrients to pass from the outside world into your bloodstream.  

While some permeability, or “leakiness,” is natural, too much is not a good thing for your health.  You want to get the nutrients in while keeping dangerous molecules and bad bacteria out.  

By maintaining a healthy and fiber-full diet, minimizing stress, and moving regularly, you can greatly improve the strength and health of your GI tract and yourself.

Read Next: Top 5 Best Digestive Enzyme Supplements to Fix Leaky Gut


    • Hi, Kitty!

      Thank you so much for your kind comment! We’re so glad you found it helpful!!

      Since Leaky Gut isn’t (yet) an official diagnosis it’s extremely difficult to say with any certainty how many people are struggling with this condition. To get a feel for how widespread it might be, the best we can do is look at the statistics for conditions linked to a leaky gut.

      So, for example, we know that about 20% of the population struggles with autoimmunity, 37% of the population is obese, about 10% of the population has diabetes and 10-15% have chronic digestive distress, 18% struggle with anxiety and about 7% have depression.

      Now, we can’t just add these percentages together and get a valid number for the percentage of people with a leaky gut because these numbers can count individual people more than once. Someone with obesity can also be depressed and have an autoimmune condition, for example, and be counted 3 times, here.

      But, given how widespread such conditions are (and the fact that this isn’t even close to a comprehensive list of all the conditions that may be promoted by a leaky gut), I think it’s safe to say that leaky gut affects a significant portion of the population.

      I hope that kind of answers your question! I’m sorry that there isn’t more concrete data I could share with you! Once the data is in, we’ll pass it along!

      In Health,



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