Do You Know The 10 Foods That Can Cause A Leaky Gut? What To Avoid To Keep Your Gut In Optimal Health

Grain And In A Basket

If you’ve spent any time reading about health and wellness, chances are high that you’ve come across the term leaky gut syndrome. Although it is talked about a lot in functional medicine, this insidious gut problem is vastly misunderstood amongst most people. 

Since starting my telehealth functional medicine clinic over a decade ago, I have helped thousands of patients overcome their gut problems and heal from leaky gut syndrome. So what have I learned after all these years? Food is without a doubt the biggest trigger of leaky gut syndrome - but it is also your greatest healing tool if used correctly. Without further ado, let’s dive in to learn more about leaky gut syndrome, the top foods that cause leaky gut, and the best superfoods you can eat to restore your gut health.


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What is leaky gut syndrome?

Also referred to as intestinal permeability, leaky gut syndrome is a condition that happens when your delicate gut lining is damaged, allowing for undigested food particles to pass through your digestive tract into your bloodstream where they don’t belong.

Symptoms of leaky gut syndrome

Even though leaky gut syndrome is a digestive health problem, its symptoms are not limited to digestive distress. Since your gut is the foundation of your entire health, symptoms can manifest in various areas of your body. That’s why so many people struggle for years without any answers to their health woes. They end up bouncing from doctor to doctor until they find someone who understands leaky gut syndrome, acknowledges their symptoms, and is able to put together all the pieces of their health case.

Some of the most common symptoms of leaky gut syndrome include:

  • Acid reflux
  • Anxiety
  • Bloating
  • Brain fog
  • Depression
  • Constipation
  • Fatigue
  • Food sensitivities
  • Gas
  • Headaches
  • Joint pain
  • Nutrient deficiencies
  • Skin problems (acne, rashes, eczema)
  • Weight loss resistance

The real problem occurs if a leaky gut is left unchecked for a prolonged period of time. When this happens, your body increases levels of pro-inflammatory cytokines as its defense mechanism against the undigested food particles and bacteria entering your bloodstream. This chronic inflammation throws you into the autoimmune-inflammation spectrum that can ultimately lead to the development of autoimmune conditions like Inflammatory Bowel Disease (IBS), Hashimoto’s Thyroiditis, Type 1 Diabetes, and more.

What is the number one cause of leaky gut?

There is no single cause of leaky gut syndrome. Instead, there can be multiple factors that contribute to the development of leaky gut. Ultimately, it all depends on the individual as the health of no two people look exactly the same, but according to a recent 2023 study published in the journal Molecules, these are the most common causes (1) of leaky gut syndrome:

  • Poor diet
  • Chronic Stress
  • Frequent medication use (NSAIDs, antibiotics)
  • Chronic infections (H. pylori)
  • Alcohol

What does the latest research say about leaky gut syndrome?

While we know more about gut health than ever before, conventional medicine still doesn’t acknowledge leaky gut syndrome as a legitimate, standalone diagnosis. Instead, it is considered a sort of gray area condition, characterized by common symptoms like bloating and food sensitivities coupled with intestinal permeability. 

With that being said, the influence your gut has on your overall health can’t be denied - even in mainstream medicine. That’s why there is continuously new research being done on this relationship, with results further proving what us in functional medicine have known for years. 

In fact, the same 2023 study I referenced earlier continues to show the link between intestinal permeability and conditions like obesity, heart disease, non-alcoholic fatty liver disease, celiac disease, and the many inflammatory autoimmune conditions I mentioned previously. Needless to say, leaky gut syndrome and its effects are very real - whether you want to consider it a legitimate diagnosis or not!

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How do I know if I have leaky gut?

Since leaky gut syndrome and other gut health problems like bacterial dysbiosis and SIBO can have similar symptoms, I always run specific leaky gut labs in my telehealth functional medicine clinic to determine whether or not this is a factor in your health case.

The first is to look for the presence of zonulin and occludin antibodies. As these two proteins control the permeability of your gut, the presence of antibodies indicates that there is damage to the tight junctions sealing your gut lining. I also look for the presence of lipopolysaccharide (LPS) antibodies anywhere outside of your gut, since they should only be found in your digestive tract if your gut lining is intact.

What foods should be avoided with leaky gut?

Although no two people are the same when it comes to diet, there are certain foods that cause leaky gut when eaten in excess. These are the foods I’ve seen trigger leaky gut syndrome in my patients and why you should avoid these if you want are working on healing your gut.

1. Sugar

Sugar overload is the common denominator between many of the health problems I see in my clinic. Again, not everyone is going to benefit from the same diet, but I’ve never seen someone who does well with increased sugar intake, especially when it comes to gut health. This is because sugar is the preferred fuel of many strains of bad bacteria in your gut. By feeding them a never-ending buffet of sugar you are essentially taking away control from the good bacteria that keeps your gut lining intact and inflammation under control.

Plus, sugar intake can result in chronically high blood sugar which also doesn’t do your gut any favors. When your blood sugar spikes, it actually increases AGE (advanced glycation end products) compounds in your body which have been linked to increased gut permeability. 

2. Artificial sweeteners

Cutting out sugar isn’t an excuse to switch to artificial sweeteners instead. As it turns out, aspartame, sucralose, and other alternatives can be even more damaging to your gut in the long-run than regular sugar. Need some help breaking the sugar habit? Check out my guide to cutting out sugar for good.

3. Grains

Both gluten and gluten-free grains can damage your gut health. They are loaded with amylose sugars that bad bacteria thrive off of which fuels bacterial overgrowths and inflammation. Grains to avoid include rice, corn, quinoa, barley, and wheat along with any products made with these such as baked goods, breads, cereal, and pasta.

4. Dairy

I apologize in advance to all my cheese lovers, but there are many reasons to avoid dairy if you want to keep your gut health in check. In fact, dairy is one of the most common food sensitivities in the world, most likely due to the fact that the conventional dairy we consume today is higher pro-inflammatory omega-6 fats from cows pumped full of hormones and fed inflammatory grains. 

I’ve found that people with leaky gut syndrome can’t tolerate dairy for these reasons but once their gut is healed, they can handle small amounts of dairy from grass-fed cows. To learn more about dairy intolerance and how dairy could be contributing to your symptoms, check out my article here. Types of dairy products to avoid include yogurt, milk, ice cream, cheese, sour cream, and butter.

5. Alcohol

A glass of wine or a cocktail every once in a while isn’t going to damage your gut. But if you have leaky gut syndrome, it is worth considering taking a break from alcohol for the time being. Alcohol is a known gut irritant and can play a role in suppressing the hormones and detox pathways in your body that are responsible for controlling inflammation and gut permeability.

6. Industrially processed seed oils

A cheaper alternative to higher quality oils like avocado and coconut, industrialized seed oils are used in almost all pre-packaged products you find at the grocery store. I recommend avoiding these at all costs as they are highly processed and inflammatory in nature which can further perpetuate gut permeability. These include canola, corn, grapeseed, safflower, soybean, sunflower, vegetable, and any other oil labeled “partially hydrogenated”.

7. Processed foods

Processed foods are typically made with these highly inflammatory industrialized seed oils and other ingredients likely to irritate your gut. A recent study published in Science Advances (2) found that a diet high in processed foods was a key driver of intestinal permeability and increased the risk of developing microvascular diseases like Chronic Kidney Disease.

8. Legumes

Legumes like black beans, chickpeas, navy beans, pinto beans, and peanuts contain lectins that bind to your intestines and irritate your tight junctions leading to leaky gut syndrome. 

9. Soy

Soy is considered a phytoestrogen, a type of plant-based estrogens that your body does not produce through the endocrine system. Not only can this mess with your hormones, the majority of conventional soy is grown with pesticides that have been linked (3) to inflammation and leaky gut syndrome. Soy in the form of tofu is commonly used as a plant–based meat alternative and as a plant-based protein source in protein powders and bars.

10. Raw vegetables

Now, this is not a hard and fast rule when it comes to a leaky gut. I can say though that from my experience, cooked vegetables are easier on your gut than raw vegetables as they require less work from your digestive system to break down.

What foods help heal leaky gut?

Just as there are foods that cause leaky gut, there are foods that help heal a leaky gut. These are the top foods I recommend for healing a leaky gut as they contain nutrients that have been shown to help restore microbiome balance, reduce inflammation, and repair a damaged gut lining.

1. Fermented foods

A healthy gut starts with a balanced microbiome. Bacterial dysbiosis happens when the bad bacterial strains in your gut outnumber the good strains, leading to increased inflammation and gut permeability. Load up on probiotic-rich foods like coconut yogurt, sauerkraut, and kimchi to win the battle against leaky gut.

2. Healthy fats

Healthy fats from coconuts, avocados, and ghee work to lower inflammation and restore blood sugar levels.

3. Fiber

In order to have a healthy gut you need probiotics and prebiotics. While probiotics work to introduce good bacteria into your gut, prebiotics in the form of fiber act as fuel for the good bacteria already in your gut so they can multiply and thrive. Foods high in prebiotic fiber include sweet potatoes, asparagus, apples, artichokes, onions, and garlic.

4. Bone broth

Bone broth is liquid gold for anyone with gut problems. Sipping on this throughout the day can be a great way to get in essential nutrients your body needs while giving your gut a break from the process of digestion. Plus, bone broth is filled with gut-healing nutrients like collagen that have been shown to have a calming effect on inflammation and can heal a damaged gut.

5. Clean protein

Grass-fed beef, lamb, and wild-caught fish, are all higher in omega-3 fats than their conventional counterparts that have powerful anti-inflammatory capabilities.

6. Low-fructose fruits

Berries are an example of low-fructose fruits that won’t spike your blood sugar or contribute to bacterial overgrowths that lead to intestinal permeability.

Example one day meal plan

If you are new to using food as medicine, changing your diet can be very overwhelming -  especially when we consider that a lot of these gut irritating foods are staples of the American diet! Instead of focusing on what you can’t eat, here’s an example of all the amazing meals you can eat in a day while healing your gut.

Breakfast: Avocado Sweet Potato “Toast”

Cut up a sweet potato into a couple large slices. Bake in the oven until cooked through and top with mashed avocado seasoned with garlic, sea salt, pepper, and a little lemon juice.

Lunch: Salmon Poke Bowls

Cook up some frozen cauliflower rice and add to a bowl with a handful of diced wild-caught salmon. Top with seaweed flakes, coconut aminos (a great soy sauce alternative!), some avocado, and whatever other toppings you’d like for a fresh, filling lunch.

Dinner: Chicken soup

Make a big pot of this and you won’t have to worry about dinner for the whole week! Add in some pre-cooked, shredded chicken to a large pot of bone broth with zucchini noodles and whatever vegetables you have on hand. Let simmer until vegetables are cooked through.

Supplements for leaky gut

In functional medicine, food is always the foundation to your overall health. As I have said many times before, you can’t supplement your way out of a poor diet. However, when you are in the thick of your health problems, supplements are a great tool to speed up your healing time and support the efforts you are making with your diet.

1. Probiotics

It can be difficult to get enough beneficial probiotics through food alone to make a significant difference in your gut health. Taking a high-quality probiotic supplement like The Probiotic from my supplement line The Collection will ensure you are getting at least 100 billion CFUs of four clinically-proven strains of beneficial bacteria per day.

2. L-glutamine

L-glutamine is the preferred fuel source of your enterocytes - you know, the ones that cover your intestinal lining. Since we want to increase their turnover rate to restore your gut lining, supplementing with this on a daily basis can speed up your healing time. You can find l-glutamine in powdered form to add to your smoothies or mix into a glass of water.

3. Slippery elm

This natural botanical produces a protective film in your gut lining to soothe and reduce inflammation. You can find this in supplement form, but I recommend sipping slippery elm tea to really harness its soothing properties.

What is the fastest way to heal leaky gut?

There is no quick fix for leaky gut syndrome. In a healthy individual, the cells inside your gut lining naturally regenerate themselves, essentially giving you a brand new gut lining every 2 weeks! But in the case of leaky gut syndrome, long-term sustainable healing can take anywhere between 12 and 24 months with many people noticing continued improvement of their symptoms with each passing month.

READ MORE: The 14 Best Herbs For Intestinal Inflammation

Seeking help from a functional medicine doctor

Even though we are still learning about leaky gut syndrome in conventional medicine, functional medicine practitioners like myself have been helping people heal from intestinal permeability for years. If you think you have leaky gut syndrome, you don’t have to be stuck taking medications for the rest of your life that only act as a bandaid for your symptoms.

Instead you can use food to your advantage and begin to heal a damaged gut lining by avoiding damaging foods like gluten, grains, sugar, and dairy and increasing your intake of superfoods like healthy fats, fiber, and fermented foods.

If you are ready to take the next step in healing your gut, schedule a telehealth functional medicine consultation today.

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe.

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  1. Aleman RS, Moncada M, Aryana KJ. Leaky Gut and the Ingredients That Help Treat It: A Review. Molecules. 2023 Jan 7;28(2):619. doi:10.3390/molecules28020619. PMID: 36677677; PMCID: PMC9862683.
  2. Snelson M, Tan SM, Clarke RE, de Pasquale C, Thallas-Bonke V, Nguyen TV, Penfold SA, Harcourt BE, Sourris KC, Lindblom RS, Ziemann M, Steer D, El-Osta A, Davies MJ, Donnellan L, Deo P, Kellow NJ, Cooper ME, Woodruff TM, Mackay CR, Forbes JM, Coughlan MT. Processed foods drive intestinal barrier permeability and microvascular diseases. Sci Adv. 2021 Mar 31;7(14):eabe4841. doi: 10.1126/sciadv.abe4841. PMID: 33789895; PMCID: PMC8011970.
  3. Samsel A, Seneff S. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdiscip Toxicol. 2013 Dec;6(4):159-84. doi: 10.2478/intox-2013-0026. PMID: 24678255; PMCID: PMC3945755.

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Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is the host of the popular The Art Of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, The Inflammation Spectrum and the brand new book Gut Feelings: Healing the Shame-Fueled Relationship Between What You Eat and How You Feel.

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Healing The Shame-Fueled Relationship
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