The term "leaky gut" has gained a lot of attention in recent years.
Also known as increased intestinal permeability, it's a condition in which gaps in your intestinal walls start to loosen. This makes it easier for larger substances, such as bacteria, toxins, and undigested food particles, to pass across the intestinal walls into your bloodstream.
Studies have associated increased intestinal permeability with several chronic and autoimmune diseases, including type 1 diabetes and celiac disease.
The leaky gut syndrome affects millions of people worldwide, and many don't even know they have it. That's because the causes of the leaky gut syndrome are in places you might not expect, such as foods you believe to be healthy.
The good news is, by making simple changes to your diet and using a tool to maintain a healthy gut lining, you can prevent and reverse leaky gut syndrome and lower your risk for developing an autoimmune disease and other issues.
Leaky gut, or increased intestinal permeability (IP), is a condition that creates gaps in the lining of the intestinal walls. These gaps allow food particles, bacteria, and waste products to seep directly into the bloodstream. Eating foods that positively influence intestinal bacteria and inflammation can help relieve symptoms.
The intestinal wall consists of epithelial cells. Tiny gaps between these cells allow water, ions, and other nutrients to flow from the intestines into the bloodstream. Usually, food and waste particles cannot pass through these gaps.
In leaky gut syndrome, however, inflammation and bacterial imbalances in the gut cause these gaps to expand. This allows harmful substances to leak into the bloodstream.
The foods you eat and the way you feel are often connected. For example, eating too much at dinner can make you feel bloated, while a healthy breakfast provides you with the energy you need to power through the morning. Are tomatoes bad for leaky gut? Digestion problems like gas, diarrhea, and constipation affect millions of Americans, and more than 15% of people in Western countries have severe gut sensitivity.
One particular digestive condition affecting general health is a leaky gut syndrome, referred to in the medical community as intestinal permeability. Inside your body, there's an intestinal lining that forms a tight barrier to control what substances your body absorbs. If you have a leaky gut, it means your intestinal lining has large cracks and holes that allow toxins and partially digested food to pass into your bloodstream.
Over time, the leaky gut syndrome may damage your gut flora, the healthy bacteria in your stomach. Some research suggests this condition can trigger inflammation and cause problems in your digestive tract and throughout your body, leading to chronic disease.
Whether they're adding a delicious pop of colour to summer salads or making your savoury sauces sing, tomatoes are one of the most well-loved prebiotic foods around. Although technically a fruit, tomatoes are typically classified as vegetables—and they belong to the infamous nightshade family, which also includes eggplants, peppers, and potatoes.
Not so long ago, nightshade vegetables were thought to be unhealthy, but thankfully we now know so much better! Not only are tomatoes recognized for their far-reaching lycopene benefits, the latest research indicates that they're also a yummy way to support a healthy, balanced gut.
What is a leaky gut syndrome (or intestinal permeability)?
At the most basic level, a leaky gut means your intestines aren't quite as secure as they should be.
Here's a quick biology lesson: The walls of the intestines are supposed to be permeable to a degree. This is how the nutrients we eat make it into the body, while other parts of food we can't use continue through the intestines and eventually leave as waste. So ideally, the barrier of the intestines would only allow tiny nutrients to absorb into the bloodstream and excrete unwanted particles.
The problem occurs when the intestinal tight junctions—the spaces between the single layer of cells that regulate what enters the bloodstream—are injured (which can happen for various reasons like poor diet and stress). This allows unwanted microbes and undigested food particles to "leak" into the bloodstream, where the immune system often marks them as foreign invaders and attacks. This is considered leaky gut or increased intestinal permeability.
Increased intestinal permeability plays a role in some gastrointestinal conditions, like celiac disease, Crohn's disease, and irritable bowel syndrome (IBS). However, while scientists agree that increased intestinal permeability is related to these gastrointestinal issues, it's not clear whether the leaky gut is the cause or a side effect.
Other studies suggest leaky gut may be connected to autoimmune diseases, such as arthritis and thyroid disorders.
What causes a leaky gut?
So, what causes increased intestinal permeability? A 2013 study points toward zonulin, a human protein that researchers described as "the only known...modulator of intercellular [tight junctions] described so far." When zonulin is released, the tight junctions of the intestines can break apart.
According to research, bacteria and gluten have been shown to trigger zonulin release in the small intestine. This is why many functional nutrition experts suggest dietary changes, like a gluten-free diet, to help manage the symptoms.
Other factors contributing to a leaky gut include medications, like non-steroidal anti-inflammatory drugs (NSAID), antibiotics, stress, and environmental factors. However, there's still no definite cause of leaky gut.
Foods to eat
As the leaky gut syndrome isn't an official medical diagnosis, there is no recommended treatment.
Yet, you can do plenty of things to improve your general digestive health.
One is to eat a diet rich in foods that aid the growth of beneficial gut bacteria. Conversely, an unhealthy collection of gut bacteria has been linked to poor health outcomes, including chronic inflammation, cancers, heart disease, and type 2 diabetes.
The following foods are great options for improving your digestive health:
- Vegetables: broccoli, Brussels sprouts, cabbage, arugula, carrots, kale, beetroot, Swiss chard, spinach, ginger, mushrooms, and zucchini
- Roots and tubers: potatoes, sweet potatoes, yams, carrots, squash, and turnips
- Fermented vegetables: kimchi, sauerkraut, tempeh, and miso
- Fruit: coconut, grapes, bananas, blueberries, raspberries, strawberries, kiwi, pineapple, oranges, mandarin, lemon, limes, passionfruit, and papaya
- Sprouted seeds: chia seeds, flax seeds, sunflower seeds, and more
- Gluten-free grains: buckwheat, amaranth, rice (brown and white), sorghum, teff, and gluten-free oats
- Healthy fats: avocado, avocado oil, coconut oil, and extra virgin olive oil
- Fish: salmon, tuna, herring, and other omega-3-rich fish
- Meats and eggs: lean cuts of chicken, beef, lamb, turkey, and eggs
- Herbs and spices: all herbs and spices
- Cultured dairy products: kefir, yogurt, Greek yogurt, and traditional buttermilk
- Beverages: bone broth, teas, coconut milk, nut milk, water, and kombucha
- Nuts: raw nuts, including peanuts, almonds, and nut-based products, such as nut kinds of milk
Tomatoes and Your Gut
It's no secret that tomatoes rank high on the list of gut-healthy foods. As an excellent source of prebiotic fibre, tomatoes provide your microbial good guys with the perfect nutrition they need to thrive and encourage every system in your body to function at full capacity.
The prebiotic effect of tomatoes is surprisingly powerful—not only does raw and cooked tomato fibre nourish friendly bacterial species like Lactobacillus rhamnosus and Bifidobacterium bifidum, but it also helps these and other strains of probiotics attach themselves to intestinal epithelial cells.
Even when a diet is less than optimal, tomatoes still seem to have a positive, protective effect on gut balance, potentially compensating for otherwise poor food choices. In one study, a group of rats eating a diet heavy in unhealthy fats for five weeks was also given tomato juice. At the end of the trial, this group of rats significantly increased their Lactobacillus numbers (which normally decline on this type of diet).
But scientists are learning that the positive effects of tomatoes are actually more holistic—with antioxidants and prebiotics working synergistically with the microbiome itself to benefit the entire gut.
An exciting new study from Spain put tomatoes to the test to explore how they might interact with beneficial gut bacteria. Tomatoes are naturally rich in lycopene, an antioxidant pigment that's getting lots of attention these days due to its ability to protect cells from damage. For this study, researchers worked with raw and cooked pear tomatoes—a variety with a particularly high lycopene content—in order to see how this pigment affected the microbiome.
Foods to avoid
People who experience unpleasant gastrointestinal symptoms may want to avoid eating foods that are difficult to digest. Experts refer to these foods as fermentable oligo-, di-, monosaccharides and polyols (FODMAPs).
FODMAPs are short-chain carbohydrates, which bacteria break down, or ferment. This fermentation process results in the production of gas, which causes uncomfortable symptoms such as bloating and flatulence.
Examples of FODMAPs include:
Adopting a low FODMAP diet may reduce gas production. This, in turn, may help alleviate the digestive discomfort that leaky gut syndrome brings.
High FODMAP foods to avoid include:
- fruits such as apples, cherries, peaches, pears, goji berries, dates, and watermelon
- vegetables including asparagus, mushrooms, onions, and garlic
- legumes, such as black beans, fava beans, kidney beans, and chickpeas
- natural and artificial sweeteners, including fructose, honey, xylitol, sorbitol
- grains such as wheat, flour, barley, rye, and almond meal
- beverages including soda, fruit juice, beer, and wine
In addition to following the eating plan described above, it's beneficial to avoid exposure to potential "toxins" found in tap water, alcohol, cigarettes, pesticides, NSAID pain-killer medications and antibiotics, all of which can stress the gut. However, always consult with your physician if they have prescribed these for you.
Another tip is to consider following an elimination diet at first. Some foods seem to be in a "grey area" when it comes to worsening or promoting digestive health. For example, some people do better with certain protein foods than others do.
You may be wondering, are eggs bad for leaky gut? What about beans and legumes?
People who think that they may have leaky gut syndrome can try making dietary changes to manage their symptoms.
Not everyone responds in the same way to different foods. People can try keeping a food diary to identify foods that trigger leaky gut symptoms.
People should consider seeing a doctor if their symptoms do not improve despite incorporating the above dietary changes.
The leaky gut syndrome is a condition in which the cellular junctions of the intestinal wall become damaged, allowing undigested food and bacteria to "leak" into the bloodstream. Leaky gut has been implicated in many autoimmune disorders like IBS and celiac disease. However, it is not yet a widely recognized medical condition, and more research is needed to understand the cause and proper treatment methods.
You may choose to eliminate eggs and legumes at first and then reintroduce them after several weeks. This can help you uncover whether they are problematic for you or not.
Instead of eggs and legumes, try meat, poultry, fish and collagen protein or bone broth protein powder instead.
Frequently Asked Question About Leaky Gut
If you have the leaky gut syndrome, you should avoid these foods: refined carbohydrates, glutinous grains, white sugar, dairy products, vegetable oils, artificial sweeteners, alcohol, and caffeine. This is because the foods you eat and the way you feel are often connected.
Lemons are rich in vitamin C and fibre – and that gives them a range of benefits for supporting gut health. As a potent antioxidant, vitamin C protects the cells against free radicals and can reduce gut inflammation and boost the immune system.
Intermittent fasting is not recommended for everyone. The ability of intermittent fasting to lower inflammation has been proven (25). More recent research has shown that alternate-day fasting and time-restricted fasting methods appear to improve gut permeability. This means they make the gutless leaky.
Yes, a leaky gut can definitely cause weight gain, but it can also cause an inability to gain weight or muscle. So leaky gut causes weight gain but indirectly.