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Foods That Cause Leaky Gut
“Leaky gut” refers to a syndrome in which gaps form in your intestinal wall. These gaps allow bacteria, sugar, and plant toxins to cross the intestinal barrier and enter your bloodstream. Though leaky gut is a relatively new area of study, many common foods have been found to contain compounds that cause leaky gut.
Also known as “increased intestinal permeability,” leaky gut has been associated with various chronic inflammatory and autoimmune diseases, including arthritis, celiac disease, and diabetes.
In this article, we’ll explore the foods that cause leaky gut. We’ll also offer an anti-leaky gut food list.
Table of Contents
What is Leaky Gut?
Leaky gut is the colloquial name for increased intestinal permeability.
Our intestines comprise more than 4,000 square feet of surface area, all of which is protected by a mucosal membrane. When this membrane is healthy it controls what nutrients and compounds get absorbed into our bloodstream–allowing only those that are beneficial.1 2
Foods that damage the intestinal lining create gaps between mucosal membrane cells. These gaps allow plant toxins, antinutrients, bacteria, sugars, pesticides, and undigested food particles to enter your bloodstream. 3
Once in the bloodstream, these particles are carried to various organs and tissues in the body, where they either cause direct damage or are detected as antigens by your body. Your body responds to antigens with an inflammation.
If leaky gut goes unchecked, it can lead to chronic inflammation, autoimmune disorders, advanced aging of joints and organs, and mood disorders, among other issues.
The good news is that the root of this syndrome is likely the foods we eat that cause leaky gut.
Eliminating the foods that cause leaky gut and replacing them with foods that support your gut lining can restore your health from the gut up.
Leaky gut is also implicated in numerous other disorders:
|Infectious diarrhea||Infections (e.g., respiratory)|
|Irritable bowel syndrome; functional gastrointestinal diseases||Acute inflammation (sepsis, systemic inflammatory response syndrome, multiple organ failure)|
|Inflammatory bowel disease, Celiac disease||Chronic inflammation (e.g. arthritis)|
|Cancer (esophagus, colorectal)||Obesity-associated metabolic diseases (nonalcoholic steatohepatitis, diabetes type I and II, cardiovascular disease)|
What Causes Leaky Gut?
Though research on the causes of leaky gut is still emerging, numerous foods are shown to contain compounds that directly contribute to increased intestinal permeability.
Let’s take a look at these gut-harming compounds and the foods that contain them.
Toxins in Plant Foods that Harm Your Gut
Plants don’t have feet, fists, fangs, or other obvious ways of defending themselves. But like all other life forms, plants want to survive and replicate. To achieve goals, plants evolved an arsenal of chemical defenses known as plant toxins and antinutrients.
The human body’s first line of contact with these plant defense mechanisms is in our gut lining.
It is no surprise then that plant toxins and antinutrients are key factors in intestinal permeability. Though most cultivated plant foods are not acutely poisonous, repeated low-dose exposure can result in leaky gut.
Common plant compounds that cause leaky gut include:
Let’s take a look at the specific toxin-laden foods that cause leaky gut.
Foods that Contain Gluten
Foods with gluten can cause leaky gut in various ways.
Two known factors stimulate high levels of zonulin–one is gluten, and the other is bacteria. 8
Furthermore, most glutenous products are high in carbs and lectins, both of which can cause leaky gut.
How Gluten Affects Your Gut
When a part of the gluten molecule called gliadin enters your gut your body senses a threat and reacts with an inflammatory immune response.
The ensuing inflammation in your gut lining damages and flattens your intestinal villi. The villi are a protective hair-like structure lining your gut. Inflammation and damage to this structure can result in a leaky gut. 
The damage from gluten can happen relatively quickly on a biological scale. 15 hours after consuming foods with gluten, fragments of gliadin enter the bloodstream, where they begin to cause inflammatory damage to other body tissues.
High Gluten Foods That Cause Leaky Gut
Wheat-based foods like bread, pasta, cereal, crackers etc. Raw wheat and wheat germ contain around 300 mcg of lectins per gram . While whole wheat flour contains around 30 mcg of lectins per gram .
Other wheat derived high gluten foods include:
- KAMUT® khorasan wheat
- einkorn wheat
- Malt in various forms including: malted barley flour, malted milk or milkshakes, malt extract, malt syrup, malt flavoring, malt vinegar
- Brewer’s Yeast
Foods High in Sugar
Recent studies have shown that diets high in sugar, like the Standard American Diet, increase the relative abundance of bacteria that cause intestinal permeability called Proteobacteria.
At the same high sugar diets decrease the abundance of gut-protective Bacteroidetes. These beneficial organisms have been shown to reinforce gut barrier function and defend against endotoxins. 1
Other studies have found that high sugar diets disrupt the integrity of the intestinal barrier leading to systemic autoimmune responses.2
Foods high in sugar that cause leaky gut
To reduce the effects of sugar on leaky gut, eliminate added sugars and high carb foods, including:
- Baked goods like cookies, cakes, pastries
- Bread products–sandwich bread, bagels, pita bread etc.
- High-carb vegetables
- High-carb fruit
Foods High in Lectins
Lectins are sticky proteins that bind to carbohydrates.
Studies show that when lectins bind to cells lining your gut they can disrupt the growth of healthy bacteria and inhibit hormone signaling. 7]
Additionally, lectins inhibit digestive enzymes needed for properly metabolizing food, and they bind to zinc, iron, and calcium. 
Studies also show that lectins increase inflammation associated with IBS and autoimmune conditions like rheumatoid arthritis .
If you already have IBS or leaky gut, you are more susceptible to the negative effects of lectins and can experience them immediately.
Damage from lectins to the gut can reduce your ability to absorb protein, fat, and vitamin B12, which increases your risk of inflammatory bowel disease. 
High Lectin Foods That Cause Leaky Gut
Foods high in lectins include:
- Legumes like kidney beans, soybeans, and peas. Legumes are also high in carbs and fiber, which can contribute to intestinal dysbiosis associated with leaky gut
- Wheat-based products (gluten is a lectin) including bread, baked goods, pasta, cereals, wheat flour, couscous, etc.
- Peanuts. Studies have found lectins in the bloodstream of groups of people ate both roasted and raw peanuts.  Lectins from peanuts have also been found to cross the intestinal barrier into the bloodstream.
- Tomatoes: lectins in tomatoes are not eliminated by high heat processing . Tomatoes also contain a plant toxin called tomatine that can accumulate in the body and become mobilized in times of stress..
- Corn: Accounting for around 60% of global food production, many people eat corn that is minimally cooked, allowing lectins to pass into the gut
- Squashes including pumpkin, acorn squash, zucchini, and butternut. Lectins in squash are found mostly in the skins and seeds 
- peppers (bell and hot peppers, including jalapenos)
- goji berries
High Oxalates Foods
Oxalates are another class of naturally occurring plant compounds that help plants but can harm humans.
High Oxalate Foods That Harm Your Gut
High oxalate foods include many of the most popular fruits, veggies, and seeds:
- Spinach: Just 100-gram portion of spinach contains approximately 645 milligrams of oxalate
- sesame seeds
- sweet potato
Due to their high lectin and glycoalkaloid content, potatoes deserve their own category.
Glycoalkaloid toxicity from potatoes can occur after consuming just 1 mg of glycoalkaloids per kg body weight.
For the average 150 lbs person, toxicity can occur after eating only 68 mg of glycoalkaloid. Fatality can occur after consuming 302 mg.
Due to these dangers, the maximum allowable level of glycoalkaloids is 20 mg of total glycoalkaloids per 100 g (fresh weight) of potatoes. 
Glycoalkaloid levels in common potato products 
|FOOD TYPE||CHACONINE||SOLANINE||TOTAL GLYCOALKALOID CONCENTRATIONS|
|POTATO CHIPS (1 OZ BAG)||.36-.88 mg||.29-1.4 mg||2.7 -12.4 mg/28-gram bag|
|FRIED POTATO SKINS (4 OZ)||4.4-13.6 mg||2.0-9.5 mg||6.4- 23.1 mg/4 oz|
Vegetable oils are highly processed industrial products that are bad for your gut.
Most vegetable oils are made from GMO crops that are engineered to contain extra high levels of lectins in order to resist pests.
Conventional seeds and legumes are also sprayed with the pesticide glyphosate (Roundup), which has been shown to have extremely negative effects on gut health. In fact it may be the main reason behind the dramatic rise in Celiac disease.
Vegetable oils also contain high percentages of omega-6 fatty acids, which are linked to inflammation .
Common vegetable oils include:
- Corn oil
- Soybean oil
- Sunflower oil
- Safflower oil
- Canola oil
Food Contaminated with Mycotoxins
Mycotoxins are toxic compounds that form when certain molds grow on plant foods.
Studies show that mycotoxins cause leaky gut by attacking all four aspects of intestinal protection, including mucosal (physical), chemical, immunological, and microbial barriers. 3
Foods High In Mycotoxins That Cause Leaky Gut
The following foods often contain mycotoxins that cause leaky gut:
- Grains: corn, wheat, barley, rye
- Nuts: peanuts, pistachios, and Brazil nuts
- Sugar: from cane and beets
- Coffee beans
- Dried fruit: apricot, figs, plums, dates, quince
- Beer and wine
Food to Eat to Heal Your Gut
Now that we’ve identified that plant food, processed foods, and high sugar foods cause leaky gut, let’s turn to the foods that can nourish your gut.
A 2019 study by Dr. Sawn Baker’s Revero health program, surveying over 12,000 participants in carnivore diets, found that 95% reported improvements in gastrointestinal conditions.
Gut-Healing Foods List
Retinol has been shown to be inversely associated with intestinal permeability (7)
|Ruminants||Pork||Poultry||fish||seafood||Organ meats||Wild meats||fat||Eggs||Dairy||Fruits and Veggies|
Foods That Cause Leaky Gut: The Bottom Line
The gut is the first physiological defense against food contaminants.
Repeated exposure to contaminants can compromise the four aspects of intestinal protection, including mucosal (physical), chemical, immunological, and microbial barriers.
When this happens, gaps can form between the cell structures of your gut, allowing contaminants to pass into your bloodstream, where they can spread to every other part of your body. This syndrome is called leaky gut
The foods that cause leaky gut are high in various gut-harming compounds, including:
- Various other plant toxins and antinutrients
Common foods that cause leaky gut include
- Wheat products
- Processed foods
- Foods high in sugar
- Plant foods high in oxalates
- Plant foods high in lectins
- Plant foods contaminated with mycotoxins
To avoid foods that cause leaky gut, limit your exposure to these foods, and replace them with nourishing foods free of contaminants, including fresh meat and unprocessed animal products.