TL;DR A leaky gut happens when your gut lining—normally a strong barrier—becomes weak, letting unwanted substances like undigested food, chemicals, or bacteria slip into your bloodstream. This can trigger digestive discomfort, food sensitivities, fatigue, and even skin or mood issues. Common causes include an unhealthy diet, stress, high histamine levels, and environmental chemicals. Luckily, improving your gut health is possible! Focus on whole foods, reduce stress, and consider gut-supportive supplements like those in our Gut Health Bundle. Your gut plays a key role in how you feel every day—start nurturing it today!†
What Is Leaky Gut?
A healthy gut acts as a fortress, selectively allowing beneficial substances in while keeping harmful ones out. However, in the case of a leaky gut, this protective barrier weakens, letting unwanted particles slip through.1
Think of your gut like a long tube that runs from your mouth to your anus, and it has two key jobs to do:
- It lets the good stuff enter your bloodstream, like vitamins and nutrients from your food.
- It keeps the bad stuff inside the tube, like bacteria and harmful chemicals, so you can get rid of them when you poop.
So, a leaky gut happens when small openings in your intestinal walls become larger than they should be, allowing things to pass through that normally wouldn’t.
Why is Leaky Gut Bad for You?
If your gut has holes, harmful substances can easily slip into your bloodstream, such as:2
- Undigested proteins from food contribute to food allergies and constant immune system activation
- Bacteria
- LPS (a toxin produced by some bacteria)
- Histamine
- Chemicals like heavy metals and industrial pollutants
This isn't supposed to happen and can lead to various health issues.
The problem is that a leaky gut can start quietly, without any obvious signs at first. Over time, the walls of your gut become weaker. When you finally notice something is wrong, it often begins with digestive problems. If left unchecked, these issues can spread to other parts of the body, leading to constant immune system activity and long-term inflammation. It is, for example, connected to the development of several autoimmune diseases, allergies, mood disorders, skin conditions, and even more serious conditions.3,4

What Are Leaky Gut Symptoms?
Leaky gut is associated with various symptoms that can affect your entire body.
If you're experiencing a leaky gut, you may notice several common signs, including:
- Digestive problems like bloating, gas, or diarrhea. After eating, you may feel uncomfortably bloated and gassy, making it difficult to focus on tasks. Also, if you’ve been told you have an irritable bowel, it often means that doctors aren’t entirely sure what’s causing your gut troubles, and they are probably related to a leaky gut.
- Bloody stools. A leaky gut can lead to inflammation and damage of the intestinal lining, potentially causing small tears or ulcerations that result in visible blood in the stool.
- Frequent food sensitivities or allergies. You may notice that you often feel sick after eating dairy products, thinking you may have developed a new food sensitivity.
- Skin issues such as acne or eczema. You may still struggle with persistent breakouts on your cheeks and forehead despite trying various skincare routines.
- Constant fatigue or low energy. Even after a full night's sleep, you may yawn throughout the day and struggle to stay awake.
- Headaches or difficulty concentrating. You may lose focus while trying to work, and a dull ache may spread across your forehead.
- Joint pain or muscle aches. You may wake up with stiff, achy joints in the morning, making it challenging to start your day comfortably.
- Mood changes, including feeling low or restless. You may often feel irritable and restless for no apparent reason.
- Difficulties losing weight. If you've been struggling to lose a few pounds, but no matter how hard you try, you can't, you could be experiencing a leaky gut.
It's important to note that these symptoms can also be caused by other health conditions. If you're experiencing any of these issues, it's best to consult with your healthcare practitioner for proper diagnosis and treatment.
What Causes Leaky Gut?
A healthy gut has tiny "gates" that control what gets into your body. These gates are controlled by a protein called zonulin. It is believed that zonulin helps your body protect itself by clearing out harmful microbes and supporting a balanced gut environment.
When everything works well, the gates open just enough to let nutrients in while keeping harmful stuff out. But if zonulin levels get too high, the gates stay open too long, letting unwanted things like bad bacteria and undigested food slip through, which can lead to health problems.
Factors like an unhealthy diet, smoking, lack of exercise, and anything that stimulates Zonulin release, damages the intestinal lining, or increases inflammation can contribute to this condition. However, beyond these basics, other factors that you may have never heard of can also play a role in damaging the gut barrier and health, such as:
- High histamine levels in the gut. Histamine can greatly damage the gut lining. High levels of histamine can come from: allergies (both environmental and food-related), food sensitivities or intolerances, eating foods and drinks that are high in histamine, stress (mental or physical), hormonal imbalances, and nutrient deficiencies. The enzyme Diamine Oxidase (DAO) helps break down histamine in the gut. If you have a dirty DAO, which means it doesn’t work properly, histamine levels can stay too high.5,6 Our free Histamine Intolerance Guide will show you how to start addressing your histamine issues.
- An imbalance in gut bacteria, or dysbiosis. This can be caused by overuse of medications like antibiotics and NSAIDs, unhealthy bile production and flow (bile keeps harmful bacteria under control), chronic conditions, infections (such as SIBO, parasites, and candida overgrowth,) and an unbalanced diet.7
- Chronic exposure to herbicides and pesticides. They can harm your gut over time and lead to gut problems. Some of them affect the gut by blocking a process in bacteria that they need to produce essential nutrients like folate and amino acids. Without these nutrients, the balance of healthy bacteria in your gut can be disrupted, contributing to gut issues like leaky gut syndrome. When you can, always opt for organic vegetables and meat.8
- Chronic stress. It can cause a leaky gut in several ways: it weakens the immune system, disrupting the balance of gut bacteria; increases histamine; and shifts your body into "fight or flight" mode, which lowers stomach acid - reducing digestion and harming the gut lining.9
- Alcohol. Yes, alcohol is especially damaging and can lead to a leaky gut in several ways: it contains high levels of histamine; it weakens your immune system and disrupts the balance of bacteria in your gut, encouraging the overgrowth of harmful yeast like candida; and when your body processes alcohol, it produces a toxic substance called acetaldehyde that is extremely damaging to your gut. 10
- Environmental chemicals. Exposure to harmful chemicals, such as pollutants, heavy metals, and microplastics, can damage the gut lining and disrupt the balance of gut bacteria.11
- Gut conditions that affect your bowel and intestines can all damage the gut lining. If you have any of these conditions, you need to be extra careful about things that can further damage your intestines.12
- Collagen disruption. This is usually due to a lack of certain nutrients like vitamin C, zinc, and vitamin A, as well as factors like stress, genetics, and chronic inflammation from, for example, autoimmune conditions.13 Collagen is vital because it helps protect the lining of your gut.
What Three Foods Cause a Leaky Gut?

Certain foods can irritate the gut and make it more prone to issues like "leaky gut." This can happen when eating things that aren’t natural, like ultra-processed foods (for example, hot dogs, packaged snacks, or soda), as well as some natural foods. These foods can cause more inflammation in your body and increase substances like histamine and zonulin, which affect gut health.
Gluten, sugar, and dairy are the three main natural foods that may contribute to a leaky gut in most people. Let's find out why:
-
Gluten is a protein in wheat, barley, and rye that can trigger zonulin release, increasing gut permeability. This can be especially problematic for people with gluten sensitivity or celiac disease, causing inflammation and damage to the gut lining.14
Even if you don’t have a diagnosed sensitivity, eating too much gluten over time could still irritate your gut, unfortunately. Gluten, a protein found in wheat, barley, and rye, can be particularly problematic if you have a gluten sensitivity or celiac disease. It can cause inflammation in your gut lining, leading to increased permeability. Even if you don't have any formally diagnosed sensitivities, consuming large amounts of gluten might irritate your gut over time. - Sugar, especially in excessive amounts, can also negatively impact gut health. It can feed harmful bacteria in your gut, creating an imbalance in your gut microbiome. This imbalance may lead to small intestinal bacterial overgrowth (SIBO), increased zonulin levels, and damage to the intestinal lining.15
- Dairy. There’s some debate about whether dairy causes a leaky gut. While some researchers believe it does, others say there’s no direct link. However, if you already have a leaky gut, certain milk proteins might make autoimmune conditions worse for some people. These proteins are similar to proteins in our own body, so when undigested milk proteins enter the bloodstream, the immune system can mistake them for harmful invaders and start attacking the body’s tissues. This is known as "molecular mimicry." Similarly, if you have difficulty digesting dairy products and are lactose intolerant, you may have inflammation in your gut, potentially causing the lining to leak.16,17
Even though these three foods can cause issues for many people, everyone is different and reacts to foods in their own way. What works well for one person might not work for someone else.
For instance, some people might have trouble digesting eggplants, while others can eat them without any problems. A healthcare professional can help you figure out how these foods affect your body.
But don’t worry—changing your diet doesn’t mean you have to give up your favorite foods. It just means finding a balanced approach. Your healthcare professional can help determine how these foods affect your gut.
How Is Leaky Gut Diagnosed?
In a nutshell, here are some common methods your healthcare practitioner can use to test for leaky gut:
- A clinical evaluation. First and foremost, your healthcare practitioner should sit down with you to get an overall picture of your symptoms and a complete medical history to rule out other health conditions and narrow down the potential causes of a leaky gut.
- A lactulose and mannitol urine test. Lactulose and mannitol are types of sugars that your intestines can absorb. When you drink a liquid with these sugars, your urine is tested to see how much moved from your intestines into your bloodstream. If there’s a lot more lactulose compared to mannitol, it could mean you have a leaky gut. Your practitioner may have you drink a special solution to measure the substances that pass into your urine.
- Zonulin blood and stool tests. These tests can check for elevated levels of zonulin or specific antibodies that may indicate a weakened gut lining.
- Microbiome testing. An imbalance in the bacteria in your gut, especially certain types that produce substances like LPS (a toxin) and histamine, is often linked to a leaky gut. A stool test. We know, yuck. But, analyzing stool samples checks for markers like zonulin that may show your gut lining isn't functioning as it should.
- A hydrogen and methane breath test. Yep, your breath can be used to investigate for SIBO, which can contribute to a leaky gut.
How Do You Fix a Leaky Gut?

Fixing a leaky gut involves changing your diet and lifestyle habits to support gut health and overall wellbeing. These changes can also support a healthy intestinal lining.
What Dietary and Lifestyle Changes Support Gut Health?
Stop Doing List:
- Avoid high-histamine foods and drinks, especially if your body struggles to break them down properly due to a dirty DAO enzyme. These can harm your intestinal lining, increase gut permeability, and lead to leaky gut problems.
- Cut out sugar, dairy, and gluten-rich foods while working on gut healing, particularly if you are sensitive to them. Work with a healthcare practitioner to reintroduce them slowly after improving your gut health.
- Avoid inflammatory foods, such as highly processed snacks, commercial baked goods, white bread and pasta, refined sugars, and deep-fried items. These can trigger gut inflammation and may cause your gut immune system to become overly reactive, increasing the risk of too much histamine and leaky gut issues.
- Avoid produce known as the "Dirty Dozen"—fruits and vegetables with the highest levels of pesticide contamination. Pesticides can disrupt your gut microbiome and contribute to a leaky gut.18
- Pay attention to how you eat. Habits like eating too fast, overeating, or not chewing your food thoroughly can lead to digestive problems. Slow down and practice mindful eating.
- Steer clear of environmental chemicals. These can upset the balance of healthy gut bacteria and lead to inflammation in your body.
- Say no to unhealthy habits like drinking alcohol in excess, smoking, staying up late, or avoiding exercise, as these can negatively impact your gut health.
Start Doing List:
- Start a food diary: Keep track of what you eat and any symptoms you experience afterward. This helps identify foods that may cause issues and guides better dietary choices.
- Eat a variety of whole, colorful foods: Include plenty of plant-based foods rich in nutrients and antioxidants that support good gut bacteria and reduce harmful ones. They also help calm gut inflammation.
- Focus on a high-fiber, balanced diet: Aim for meals with a mix of protein, healthy fats, and complex carbs like fruits and vegetables to nourish your gut and promote healthy digestion.
- Eat organic when possible: Prioritize buying organic versions of the “Dirty Dozen” to minimize exposure to pesticides and consider the “Clean Fifteen” for cost-effective non-organic options.
- Use natural sweeteners like dates, raw honey, or monk fruit in small amounts instead of regular sugar or artificial sweeteners. These natural options have more nutrients and added health benefits compared to refined sugar.
- Reduce stress: Practice relaxation techniques daily like meditation, yoga, or nature walks to support digestion and lower gut inflammation.
- Stay hydrated: Drink plenty of water and electrolytes to help your body flush out toxins and keep your gut healthy.
- Exercise in moderation: Light activities such as walking or swimming can boost gut health, but overly intense workouts may stress the gut and increase histamine production.
- Ensure you’re getting enough sleep because not sleeping well can worsen inflammation and harm your gut health.
Seeking Health Gut Health Support Supplements
You can count on Seeking Health to support your gut health needs. We offer several gut health support supplements that nurture healthy digestion, diverse gut microbiota, and histamine levels. Our supplements support a holistic approach to gut health, including sleep, exercise, and nutrition, to promote a healthy gut lining.†
Not sure where to begin? Kickstart your wellness journey with our Gut Health Bundle, which provides you with the top 4 best-selling gut health supportive supplements to start taking care of your gut health today. It includes:†

- Gut Nutrients: Offers a combination of herbs, antioxidant-like nutrients, and nutrients designed to soothe and support a healthy gastrointestinal barrier. It does not contain L-glutamine, making it suitable for those who cannot tolerate it. The convenient capsules provide a lower potency than our best-selling Gut Nutrients Powder.†
- Bile Nutrients: An effective herbal blend that enhances your liver's bile production and supports the healthy flow of bile from your gallbladder to the small intestine. For individuals without a gallbladder, it aids in facilitating bile movement from the liver into the bile duct.†
- ProBiota HistaminX A histamine-friendly probiotic specially formulated to exclude strains known for high histamine production, ideal for supporting gut health, a balanced microbiome, and promoting a healthy gut response to dietary histamine.†
- Histamine Digest: Supports your DAO enzyme directly by providing you with the DAO enzyme right in the capsule, supporting healthy histamine levels in your gut if you experience discomfort from consuming high histamine foods.†
Bonus: Receive a free copy of The Histamine Workbook when you purchase the Bundle. The workbook points you to the potential causes or contributors of high histamine in your life. There are many, and there are some odd ones. The workbook guides you on how to eliminate each contributing factor so your histamine intolerance improves bit by bit. It’s all about total load. The more factors you identify and remove, the better your gut will feel, and the quicker your leaky gut will heal.
The Bottom Line

Your gut is the gateway to your overall health, and keeping it strong should be a top priority. A leaky gut may start silently but can lead to a wide range of issues, from digestive discomfort to low energy and more. By focusing on nutrient-rich foods, avoiding irritants like gluten and sugar, and making lifestyle changes that reduce stress and inflammation, you can help restore balance to your gut. Pair these habits with targeted supplements like those from Seeking Health to give your intestinal lining the extra support it needs. With the right approach, you can nurture a healthy, happy gut—and feel the difference throughout your entire body.†

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† These statements have not been evaluated by the Food and Drug Administration (FDA). This product is not intended to diagnose, treat, cure, or prevent any disease.