- Leaky gut, or increased intestinal permeability, is a red flag that something else is out of balance in your body.
- Sometimes molecules you don’t want in your body travel across your gut wall through gaps in the tight junctions — this is “leaky gut.”
- Your gut lining is only one-cell thick, so it’s vulnerable to damage and dysfunction.
- When the tight gaps between the gut’s epithelial cells widen, toxins, microbes, and undigested food can pass through to the bloodstream.
- Once these unwanted particles reach the bloodstream, they can travel and cause system-wide inflammation.
- Several factors can disrupt the gut wall’s tight junctions, and various methods exist to address the gut lining’s breach.
- Leaky gut symptoms and the conditions associated with it are wide and varied.
- Leaky gut triggers include stress, poor diet, medications, infections, and toxins.
- Heal leaky gut by de-stressing, eating a healthy diet, avoiding unnecessary medications, conquering infections, and binding toxins.
Leaky gut is a bona fide problem, but fixing it may require a different approach than you might think.
Increased intestinal permeability, commonly called leaky gut, is a red flag that something else is not quite right in your body.
Leaky gut could be a warning sign that parasites or other microbes are dismantling your health. And toxins may be overburdening your system.
Several lifestyle factors, such as chronic stress and poor dietary choices, may also contribute to a leaky gut. Certain medications can play a role, too.
When you identify and address the underlying causes of leaky gut, you take the appropriate steps to fix the problem. Potentially, you’ll be preventing other health issues that could crop up in the future.
Read on to find out what leaky gut is, five primary triggers of the condition, and the best ways to resolve it once and for all.
What Is Leaky Gut?
The interior lining of your gut is semipermeable. This means it lets specific particles through — like nutrients — but prevents others from being absorbed from your digestive tract.
Still, sometimes molecules you don’t want in your body travel across your gut wall. This is “leaky gut.” Scientists call it increased intestinal permeability or intestinal hyperpermeability.
A small amount of leakiness is normal. These minor leaks help “educate” your immune system not to overreact to foods and your normal gut bacteria. But when there’s an uptick in leakiness, it could harm your health. (1)
When people talk about leaky gut, they’re often referring to increased permeability of the small intestine. When your small intestine wall is compromised, you may absorb undigested food, toxins, and bacteria. (2)
Still, in some conditions — such as liver disease and Crohn’s disease — the wall of your large intestine may be hyperpermeable. Such diseases can damage your large intestine. This may also allow toxins and microbes to “leak” through. (3, 4, 5, 6)
Due to its link with major diseases, leakiness of the large intestine may be more apparent. Increased permeability of your small intestine may be a little harder to identify. (7)
It helps to understand how the inner lining of your small intestine works. Here’s a peek inside.
How Your Gut Wall Works
Your small intestine has a crucial role — it absorbs nutrients. At the same time, it must keep out pathogens and toxins. Despite this critical job, only a single layer of epithelial cells line the inside of your gut.
Given that the lining of your small intestine is only one-cell thick, it’s easy to see how vulnerable it could be. It is at risk for damage and dysfunction. (1, 8, 9)
A crucial part of the gut lining that can malfunction is the tight junctions containing complex proteins between the epithelial cells. Tight junctions connect epithelial cells and regulate what can pass between them. (10)
These tight junctions are like border control agents. They’re designed only to let “good guys” like nutrients cross over from your gut into the underlying tissue. From there, they can be absorbed into your blood or lymph. (11, 12)
At the same time, the tight junctions identify and keep out the “bad guys.” These include pathogens, toxins, and allergens. It’s like a list of dangerous criminals. The border control agents consult their “most wanted” list of bad guys and refuse passage.
Still, this system isn’t perfect.
Sometimes unwanted items like bacteria and undigested food squeeze through the gaps between your gut’s epithelial cells. (13)
How does this happen? Faulty border control.
How Leaky Gut Happens
The control of your gut’s tight junctions is complex. Several factors may disrupt them, including infections, inflammation, and specific dietary components.
Here is a closer look at what’s thought to happen.
Breaching tight junctions
Harmful microbes and parasites can alter the tight junctions in your gut wall. That results in a bigger gap between your gut’s epithelial cells — leading to leaky gut. This is good news for the pathogens. Gut leakiness gives them more access to your bloodstream. (14, 15)
As for dietary factors, gluten is the best-known trigger of leaky gut. Gluten is a protein in wheat, rye, and barley. It’s particularly problematic if you have celiac disease, an autoimmune condition. But it may trigger leaky gut to a lesser extent in other people, too. (10)
So, how does gluten breach your gut’s border control system? It increases your body’s release of zonulin. Zonulin is a protein involved in controlling the tight junctions.
It’s believed that an increase in zonulin or similar border control agents opens up the spaces between the cells of your gut wall. That increases leakiness. (16)
Besides gluten, other undigested food components and toxins may also leak through your gut wall. Exactly how this happens isn’t clear. Many questions remain about exactly how the tight junctions are controlled. (1)
Addressing the breach
Immune system cells underneath your gut lining spring into action when unwelcome and unwanted molecules pass through. They aim to put microbes, toxins, and undigested food out of commission. (17)
Your immune system response to this border breach can generate a lot of inflammatory molecules. That may cause you to experience unpleasant symptoms and could worsen your leaky gut. (6)
These leaked food components are microscopic. Moreover, they don’t have free rein to travel throughout your body.
Instead, everything absorbed from your gut into your bloodstream travels first to your liver. This vital organ acts as a filtration system. It helps remove digestive debris. (13)
However, this takes away from your liver’s ability to get rid of toxins from other sources. So, toxins may build up. That can damage your liver and worsen leaky gut. (18, 19)
It could potentially become a vicious cycle.
What Are the Symptoms of a Leaky Gut?
Leaky gut symptoms vary from person to person and it might be vague or difficult to pin to a specific cause. (2)
Probably the best-known symptoms are gut-related. These may include gas, bloating, abdominal cramping, and chronic diarrhea or constipation. (2, 10, 20)
Hand-in-hand with these gut symptoms are food sensitivities. Sophisticated new research confirms that increased intestinal permeability may play a role in food sensitivities and the resulting digestive symptoms. (21, 22)
Some of this research uses live microscopic evaluation of the gut lining. This enables scientists to see changes in the intestinal tissues and cells precisely when they’re happening.
This type of live microscopic exam was used in a study of people with irritable bowel syndrome (IBS). They were given food in series from four different sources — wheat, soy, yeast, or milk — directly into their gut.
The scientists found that 50% of the people had immediate disruption of their gut barrier when exposed to these foods. The researchers could see the gut becoming leaky within minutes of injecting the foods into the small intestine. The people also developed gut symptoms, although these didn’t happen right away. (22)
That study only looked at the digestive tract effects of food sensitivities and leaky gut. But you may also experience non-digestive symptoms. These may include migraine headaches, excessive fatigue, and skin issues like eczema. (2, 23, 24, 25)
So, the symptoms of leaky gut can be diverse and far-reaching. They’re also linked with an increased risk of certain health conditions and diseases.
Conditions Linked with Leaky Gut
Having a leaky gut condition isn’t a disease per se, despite the frequent use of the phrase “leaky gut syndrome.” Instead, increased intestinal permeability is a sign of dysfunction in your gut. This faulty activity may contribute to disease.
Digestive conditions like IBS, celiac disease, Crohn’s disease, and ulcerative colitis are commonly linked to leaky gut. That’s not particularly surprising.
But studies are also linking leaky gut with a variety of non-digestive disorders and diseases. (9, 26)
Some other health conditions associated with leaky gut include: (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
- Alzheimer’s disease
- Liver disease
- Multiple sclerosis
- Parkinson’s disease
- Rheumatoid arthritis
In most of these health conditions, it’s not clear how leaky gut might play a role. Immune system reactions and inflammation may be involved. These may both promote leaky gut and result from leaky gut. Further research is ongoing. (32, 38)
5 Leaky Gut Triggers
Several lifestyle factors can increase your odds of developing leaky gut. Specific infections and toxins can also increase your risk.
Here’s a closer look at five major factors that influence the development of leaky gut. (Be sure to continue reading to the next section to find out what to do about them.)
When you’re anxious or stressed, you may get an uncomfortable feeling in your gut. You may blame it on “butterflies,” but there could be more going on in your digestive tract than you realize.
Both human and animal studies suggest that acute and chronic stress can increase intestinal permeability. (39)
In one study, healthy people were asked to give a public speech — an activity many people find stressful. Some of them had a significant increase in the stress hormone cortisol. These people also had an increase in the permeability of their small intestine during this challenge. (40)
Mast cells, a type of immune system cell, seem to play a role in this. These cells are located underneath the gut lining. Interestingly, when the people in the study were given a drug to stabilize their mast cells, the speech challenge didn’t trigger a leaky gut reaction. (39, 40)
Of course, popping a pill to control your immune cells isn’t a desirable long-term solution for stress and leaky gut. It’s better to manage your stress level to help calm mast cells.
2. Poor diet
Your diet can impact your risk of leaky gut in several ways.
Some food substances can make your tight junctions more permeable. Other dietary factors may affect your immune function and gut microbiome in ways that promote leaky gut. (1)
A western-style diet rich in sugar, highly-processed foods, and alcohol has been linked to an increased risk of leaky gut. (38)
Here’s a closer look at some of the key dietary culprits in leaky gut: (10, 41, 42, 43, 44, 45, 46, 47, 48, 49)
Gluten: As mentioned earlier, this grain-based protein is a well-known trigger of leaky gut. It can increase intestinal permeability in people with celiac disease as well as people without the autoimmune condition.
Sugar: Much of the sugar you consume is absorbed as glucose through the tight junctions of your small intestine. A lab study found that glucose increased the permeability of the small intestine. Also, consuming refined fructose — such as in sugary drinks — is linked with loss of tight junction proteins in the small intestine.
Salt: Animal studies suggest a high-salt diet may increase intestinal permeability. Salt may impact the tight junctions between gut cells. Excess salt can easily sneak into your diet. About 80% of salt intake comes from processed, packaged foods.
Low fiber: Studies suggest that a low-fiber diet may lead to thinning of the protective mucosal layer of your gut wall. It may also increase the “bad” bacteria that damage your gut.
Alcohol: Drinking alcohol can damage your intestinal tissues and increase intestinal permeability. This allows large molecules to pass through the “loosened” junctions of your gut.
Food additives: Polysorbate and monoglycerides (used as emulsifiers) may increase intestinal permeability. Hexane (used to extract vegetable oil) may be problematic, too. Many other similar food additives and processing agents may promote leaky gut as well.
As your gut barrier breaks down due to dietary and other factors, you may find yourself reacting to healthy foods. Your immune system has been “misinformed” that these beneficial foods are a problem. Resolving leaky gut (including underlying causes like parasites) will likely aid your tolerance of foods. (50)
Increased gut permeability is among some drugs’ side effects. Here are some common examples: (51, 52, 53, 54, 55, 56)
Antibiotics: One study found that taking an antibiotic for just one week may disrupt your microbiome for up to two years. That can create an imbalance between good and bad bacteria. In turn, this may impair the function of tight junctions in your gut.
NSAIDs: Nonsteroidal anti-inflammatory drugs like ibuprofen can increase your intestinal permeability within 24 hours of taking them. And, 60–70% of people who take NSAIDs long term develop damaged gut mucosa, including hyperpermeability.
Acid reducers: Heartburn drugs that suppress your stomach acid can dramatically change your microbiome. This leaves you at a higher risk for infections. Moreover, animal studies show that acid-suppressing drugs increase intestinal permeability.
A variety of infections — including bacterial, fungal, and parasitic — may increase your intestinal permeability. Many of these interfere with the tight junctions that guard your intestinal border. (15)
Here are some examples of specific microbes and other critters that may promote leaky gut: (15, 57, 58, 59, 60, 61)
Bacteria: Helicobacter pylori, a bacteria that causes ulcers, can interfere with the tight junctions in your gut. Several bacteria that cause food poisoning — including salmonella, shigella, and clostridium — can also disrupt intestinal tight junctions.
Pathogens: Rotavirus, which causes stomach upset and diarrhea, can interfere with intestinal tight junctions. It disrupts the integrity of your gut barrier.
Fungi: Candida albicans is a fungus and a normal part of your microbiome. But serious issues can result from candida overgrowth. Lab studies reveal that candida can increase gut inflammation and intestinal permeability.
Parasites: The microscopic parasite giardia can disrupt tight junctions, making your gut leaky. And, the parasitic roundworm ascaris can cause intestinal discomfort and increase gut permeability. Other parasites can harm your intestinal health as well.
Notably, in a survey of functional medicine practitioners, 69% had observed a link between parasitic infections and leaky gut. Diagnosing parasites and leaky gut can be challenging, so this may be a significant underestimate. (2)
Two major types of toxins that may contribute to leaky gut are heavy metals and pesticides. Here are some examples of the harm they can do.
Some common heavy metals include cadmium, arsenic, and mercury. These can contaminate your food, water, and the air you breathe.
In an animal study, cadmium was shown to increase intestinal permeability. This heavy metal reduces good gut bacteria. It also decreases the thickness of the protective mucus layer of the gut lining, so your gut has less resilience against damage. (62, 63)
Another animal study found that arsenic reduced mucus production in the gut lining. This heavy metal was also associated with increased intestinal permeability. (64)
Additionally, lab studies show mercury can increase oxidative damage to intestinal cells. It can also damage the junction proteins between cells. This may contribute to a leaky gut. (65)
Pesticides sprayed on crops leave a residue that you ingest when you eat those foods. These chemicals are commonly used to kill weeds and insects. Some of these pesticides may contribute to leaky gut.
For example, an animal study found that chlorpyrifos — a common insecticide — reduced tight junction proteins in the small intestine. (66)
Also, the weed killer glyphosate increases the permeability of intestinal cells. Farmers commonly use this pesticide on their crops, and homeowners use it on their lawns. (67)
The good news is that there are many ways you can support your gut and restore its normal barrier function.
How Do You Heal Intestinal Permeability?
Though several factors increase intestinal permeability, other factors help reduce it. Many of these are under your control.
Try these strategies:
You have to make a conscious effort to implement strategies to combat stress.
Ayurveda, an ancient holistic system of medicine from India, offers many stress management tools. Giving yourself a daily oil massage is one soothing strategy from this tradition. (68)
Meditation is also a popular stress reducer. This practice may be as simple as closing your eyes and focusing on breathing in and out.
In Ayurvedic transcendental meditation, you calm your mind by silently repeating a word, phrase, or sound. This practice has been shown to reduce stress and cortisol levels. (69, 70)
In the Christian tradition, you may prefer centering prayer. In this approach, you silently repeat a Christian word containing one or two syllables. For example, you might repeat “Jesus” or “Amen” while focusing on your breathing. (71)
2. Follow a healthy diet
Some food substances can reduce the permeability of intestinal tight junctions. And some can beneficially impact your immune system and microbiota. These factors play significant roles in your gut health as well. (1)
The best dietary approach is to choose a healthy diet that is mostly whole or minimally processed foods. They provide the nutrients you need for a healthy gut, including zinc. Depletion of zinc has been shown to lead to leaky gut. (1)
Whole, plant-based foods are also naturally good sources of phytochemicals, such as flavonoids. Animal studies suggest that quercetin and other flavonoids bolster tight junctions and protect against gut leakiness. Quercetin is found in fruits and vegetables like apples and onions. (72)
Plant foods are also good sources of fiber, which may deter leaky gut. For instance, animal research suggests that a high-fiber diet significantly increases tight junction proteins. These help guard the gut wall. (6, 73)
Fiber also helps nourish your good gut bacteria. In turn, these microbes produce short-chain fatty acids, including butyrate. These special fats help nourish colon cells and protect your intestinal barrier. (1, 6, 74)
Additionally, a human study found that increasing your dietary fiber intake reduces zonulin. Remember, zonulin is a protein that increases leaky gut. So, practices that decrease zonulin, like eating plenty of fiber, are smart strategies. (75)
Consuming fermented foods may also help keep your gut barrier in top form. Examples are yogurt and kimchi (fermented cabbage). They contain beneficial bacteria to control inflammation and bolster your intestinal barrier. (1, 76, 77)
Moreover, good bacteria help prevent bacterial overgrowth and the release of lipopolysaccharides (LPS). These fat-sugar complexes from bacterial cell walls weaken your gut barrier and make it more permeable. (10, 78, 79)
3. Avoid unnecessary medications
Before you take any prescribed or over-the-counter drugs, question whether they are essential to your health.
You may need some medications temporarily while working with a functional medicine practitioner to identify and treat your condition's root cause. But it’s generally best to avoid drugs when you can.
As mentioned above, some drugs that may contribute to leaky gut include antibiotics, NSAIDs, and acid reducers. If you resolve the underlying reasons for your health issues, you may find that you no longer need such medications. (10, 80, 81)
4. Conquer infections
Before you tackle infections, make sure your drainage channels are functioning well. These include your colon, liver, and kidneys.
For drainage support, you can take herbs to help with constipation. You can also take herbs to support your kidneys and liver.
With that support on board, you can tackle infections like candida and parasites.
If candida overgrows in your digestive tract, follow a candida support protocol to get rid of it naturally. This protocol includes avoiding foods that feed the fungus — particularly sugar — and supporting your drainage system.
Similarly, make sure parasites are out of the picture by completing a parasite cleanse. Many parasite-killing herbs help you get rid of the critters naturally.
5. Bind gut toxins with binders
Binders could provide critical support for your intestinal lining. They may bind and remove heavy metals, pesticides, and other toxins in your gut. (82, 83)
Through these efforts, you tackle the cycle of leaky gut head-on so you can resolve it once and for all.
Leave Leaky Gut Behind
Leaky gut symptoms like food sensitivities and digestive problems are signs of underlying health issues.
The solution isn’t to directly “plug” the leak.
Instead, you need to address the root cause(s). These may include stress, dietary indiscretions, medication side effects, toxic overload, and infections. That could consist of parasites, among other pathogens.
Make a plan to tackle these leaky gut triggers as they are relevant to you. Tactics such as stress management, parasite cleansing, and heavy metal detox could be a big help.
Once you normalize your digestion and restore your gut barrier's proper functioning, good things are in store. You’ll be able to enjoy greater control over your health now and in the future.
How will your life improve once you’ve restored your leaky gut?