Leaky gut, also known as increased intestinal permeability or gut permeability, can create havoc in your body and lead to many unwanted symptoms that make it difficult to live well. Leaky gut is also a common underlying factor in many Autoimmune disease states. The good news, however, is that there are steps you can take, especially with your diet, that can help you to heal and repair your gut and return to living life optimally.

What exactly is leaky gut?

Your gut, also known as the gastrointestinal tract, includes over 4,000 square feet of intestinal epithelial lining that controls what gets into your bloodstream. If unhealthy, your gut may have holes or cracks in it.

Leaky gut occurs when the tight junctions between the cells that line your small intestine loosen. This then allows undigested food particles, bacteria, toxins and antigens into your bloodstream and can cause an immune system reaction.

Leaky gut syndrome has been implicated as a factor in many medical conditions, including celiac disease, Crohn’s disease, Irritable Bowel Syndrome (IBS), and some autoimmune diseases, though whether it is a cause or consequence of those diseases remains unclear. ^[1] Clinically, we see great improvement in our patients, including autoimmune patients after repairing the gut barrier.

What causes leaky gut?

Causes of leaky gut are still a mystery but a number of factors, particularly relating to diet, are linked to intestinal permeability.

Research has shown that higher levels of zonulin, a protein that regulates the tight junctions that line the small intestine, may loosen tight junctions and increase intestinal permeability. Bacteria and gluten are shown to increase the production of this protein in some people.

The intestinal barrier can become damaged from a variety of factors, including:

A poor diet, high in processed carbohydrates and hydrogenated oils
Food sensitivities
Certain gut-irritating foods, such as grains, legumes, dairy and alcohol
Low stomach acid
Chronic stress
Hormonal imbalances
Medications, such as NSAIDS, antibiotics, steroids, contraceptives and chemotherapy drugs
Chronic endurance exercise and overtraining
Environmental toxins
Infections and parasites
Imbalance of the gut flora.^[2]

What are the symptoms of leaky gut?

Symptoms of leaky gut may vary depending on the underlying cause. For example:

Celiac disease can cause abdominal pain, diarrhea or constipation, fatigue, nausea and vomiting, bloating and gas, and weight loss.
IBD can cause abdominal pain, severe diarrhea, weight loss, fatigue, fever, and bloody stools.
IBS can cause abdominal pain, bloating, cramping, constipation or diarrhea, mucus in stools, and excess gas. ^[3]

What health problems can leaky gut cause?

Leaky gut can cause many issues, including:

Damage to the intestinal epithelial lining has been associated with the following conditions:

celiac disease
Variety of autoimmune diseases
inflammatory bowel disease (IBD)
irritable bowel syndrome (IBS)
ulcerative colitis
Crohn’s disease
multiple sclerosis
rheumatoid arthritis
type 1 diabetes

Healing a leaky gut

There are a number of steps you can take to heal your gut. Working with a Functional Medicine health practitioner will uncover the causes of your symptoms, investigate your current diet and lifestyle and tailor a plan to help you reduce symptoms and heal your gut.

Important strategies to heal your gut include:

Remove all food toxins from your diet
Increase your intake of high-fibre foods. The soluble fibre found in vegetables and fruit support your gut’s beneficial bacteria. Eat plenty of fermentable fibres such as sweet potato.
Take probiotic supplements which are helpful for many gastrointestinal conditions, such as IBS
Eat fermented foods like kefir, yogurt, sauerkraut, kim chi, etc
Treat any intestinal pathogens (such as parasites) that may be present
Manage your stress – gut bacteria can be harmed by chronic stress
Reduce your intake of refined carbohydrates. Too much sugar can negatively impact gut barrier function.
Reduce your use of NSAIDs. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen, and naproxen, can increase intestinal permeability
Reduce your alcohol intake. Excessive alcohol consumption may increase intestinal permeability.
Quit smoking. Tobacco smoke may increase digestive tract inflammation and is a risk factor for a number of bowel conditions.

The link between diet and leaky gut

Diet strongly influences leaky gut so it makes sense that finding a diet that works for you is one of the most important steps you can take to improve leaky gut.

Intestinal inflammation caused by a poor diet is one of the main causes of leaky gut.

Eating an anti-inflammatory diet will reduce bloating, gut pain, brain fog, fatigue and joint pain and help you to maintain a healthy microbiome and intestinal wall.

What to eat to help heal a leaky gut

In order to ensure you choose the right diet for you, listening to your body and how it responds to certain foods is critical to your recovery.

As we mentioned earlier, eating certain foods, such as gluten, can increase a protein called zonulin in the gut, which drives intestinal permeability. Zonulin is also closely linked to symptoms in people with celiac disease.

Simple rules are to eat healthy, whole foods and avoid processed foods.

Healing foods include:

A wide range of fruit and vegetables
Healthy fats, such as coconut oil, olive oil and avocados
Clean, grass-fed or wild proteins, like beef, pork, poultry, fish and eggs
Gluten-free whole grains – some people do better avoiding grain all together for a period of time to accelerate healing
Nuts and seeds
Herbs and spices

Cultured dairy products (if you are dairy tolerant)

Bone broth

Add foods to your diet that contain probiotics and prebiotics. Probiotics and prebiotics can help promote healthy bacteria in your gut. Some examples include:

kefir
kimchi
bananas
berries
probiotic yogurt

To reduce and prevent leaky gut, avoid foods such as:

Gluten and wheat-based products
Sugar
Processed and snack foods
Artificial sweeteners
Commercial sauces
Alcohol or sugary beverages
Industrial seed oils, like canola, soy and cottonseed oil ^[4]

FODMAP diet

A low FODMAP diet is often recommended in people with IBS, but it may help relieve some of your symptoms from leaky gut.

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. These fermentable short-chain carbohydrates are prevalent in the diet:

Oligosaccharides: fructans and galacto-oligosaccharides (GOS)
Disaccharides: lactose
Monosaccharides: fructose
Polyols: sorbitol and mannitol

The small intestine does not absorb FODMAPs very well. They increase the amount of fluid in the bowel and are easily fermented by colonic bacteria, thus creating more gas. The increased fluid and gas in the bowel leads to bloating and changes in the speed with which food is digested. This results in gas, pain and diarrhea.

On a low FODMAP diet, you will eat fewer of the following foods:

Cow’s milk, yogurt, pudding, custard, ice cream, cottage cheese, ricotta cheese and mascarpone
Fruits, such as apples, pears, peaches, cherries, mangoes, pears, watermelon, apricots, blackberries, nectarines and plums
Sweeteners, such as honey, agave nectar, sorbitol, mannitol, xylitol, maltitol and isomalt found in sugar-free gum and mints, and cough medicines and drops
Products with high fructose corn syrup
Vegetables such as artichokes, asparagus, Brussels sprouts, cauliflower, mushrooms, snow peas broccoli, beetroot, garlic and onions
Grains such as wheat and rye
Added fibre such as inulin
Chickpeas, lentils, kidney beans and soy products

You will eat more of the following:

Lactose-free milk, rice milk, almond milk, coconut milk, lactose-free yogurt; hard cheeses such as feta and brie
Bananas, blueberries, cantaloupe, grapefruit, honeydew, kiwi, lemon, lime, oranges and strawberries
Bamboo shoots, bean sprouts, bok choy, carrots, chives, cucumbers, eggplant, ginger, lettuce, olives, parsnips, potatoes, spring onions and turnips
Beef, pork, chicken, fish, eggs and tofu
Nuts/seeds including almonds, macadamia, peanuts, pine nuts and walnuts
Oat, oat bran, rice bran, gluten-free pasta, such as rice, corn, quinoa, white rice, corn flour and quinoa ^[5] Again, clinically we find avoiding grain for a period advantageous to accelerate the healing of the gut when compromised.

Paleo Diet

For some people, the Paleo Diet works best to reduce symptoms and heal a leaky gut. Foods that irritate the intestinal barrier and can lead to inflammation include grains, legumes, dairy products, processed foods, refined sugars and alcohol. The Paleo diet is a great framework for a whole food, nutrient-dense diet, as it eliminates these irritating and inflaming foods.^[6]

In general, paleo diets follow these guidelines.

What to eat

Fruits
Vegetables
Nuts and seeds
Lean meats, especially grass-fed animals or wild game
Fish, especially those rich in omega-3 fatty acids, such as salmon, mackerel and albacore tuna
Oils from fruits and nuts, such as olive oil or walnut oil

What to avoid

Grains, such as wheat, oats and barley
Legumes, such as beans, lentils, peanuts and peas
Dairy products
Refined sugar
Salt
Potatoes
Highly processed foods in general

The link between gut health and intestinal flora

If you have a bacterial overgrowth or gut infections, you may need a stronger approach than diet alone. Using probiotic supplements can both help repair the gut lining and rebalance an overgrowth.^[7]

Choosing the right probiotics for leaky gut is as simple as picking one from each of the three types:

Category 1: Lactobacillus and Bifidobacterium Blends, such as Lactobacillus acidophilus.

Category 2: Saccharomyces boulardii

Category 3: Soil-Based Blends, usually Bacillus species

Using one type is good, but using all three together is often best for maximum benefit. ^[8]

How we can help heal a leaky gut

Through testing and a thorough analysis of your gut microbiome and your diet and lifestyle is required to assess what is happening on the inside. Our Functional Medicine practitioners at Advanced Functional Medicine can identify what you need to restore your gut health.

How do I heal a Leaky Gut?