Rebuilding Healthy Boundaries

Healing Intestinal Permeability with Nutrition & Lifestyle

Written by Emily Grochowski, MS, RDN


While most of us are familiar with the digestive and absorptive functions of our digestive tract, fewer people are aware of the gut’s critical role as a protective barrier against harmful entities like microbes and toxins. Approximately 80% of our immune system in located within our intestines.

“Good” bacteria, or probiotics, produce white blood cells, the building blocks of our immune system. So without a healthy intestinal lining and healthy cells, our immune system is inhibited and cannot function properly.

With this in mind, one can think of the single layer of cells that make up the intestinal tract lining like a row of bricks that sit side-by-side and are held together by protein “mortar” (called tight junctions). Our intestines are meant to be an intact hollow tube that absorbs and digests our food.

If this wall is intact and healthy, nutrients and other molecules pass through the intestinal barrier efficiently; absorbing specific nutrients at specific sites of the intestines. When this barrier’s cells are not intact and the junctions are somewhat “leaky” or “permeable” (for reasons described below), undigested food proteins and harmful molecules pass through the intestinal wall prematurely, before begin digested, and the immune system responds.

The response of the immune system leads to inflammation and even worse, over time, this can contribute to autoimmune disease. If this state of increased intestinal permeability and consequent inflammation becomes chronic, the affected individual will likely suffer from the many possible negative effects of a “leaky gut”.


The inflammatory effects of a leaky gut can manifest as many conditions including:

  • Food sensitivities (one of the main indicators of leaky gut)
  • Autoimmune conditions like Multiple Sclerosis, Lupus, RA, Hashimoto’s
  • Thyroid conditions (low or high)
  • Fatigue and malabsorption of nutrients
    – Suppressed or high appetite
  • Joint or muscle pain
  • Headaches
  • Skin issues like eczema, psoriasis rosacea, and acne
  • Digestive problems like bloating and gas, constipation and diarrhea, IBS
  • Weight gain
  • Syndrome X (aka metabolic syndrome)
  • Trouble sleeping
    – Hormone Imbalance and low libido
    – Brain Fog
    – Getting sick often
    – Autistic Spectrum and sensory sensitivity
    – Depression and Anxiety

In addition, there is also evidence indicating that leaky gut syndrome may be involved in the development of Crohn’s Disease, some types of cancers (e.g. ovarian, pancreatic, gliomas), and nervous system conditions like schizophrenia and autism. Given these findings, one can begin to appreciate just how important intestinal health is for every aspect of your health (and disease) and why it is key point of focus for functional medicine nutritionists, practitioners and physicians.


There are 4 main causes of intestinal permeability (leaky gut), including:

  1. Pro-inflammatory, low-quality diet (e.g. Standard American Diet or SAD)
  2. Bacterial imbalance/overgrowth
    1. SIBO
    2. Candida
    3. E.coli
    4. Parasites
    5. Other bacterial imbalance
  3. Chronic stress
  4. Toxin overload from our environment, overuse of medications and products (skin care, toothpaste, etc) we come into contact with every day

Other conditions and practices that the data indicate may increase intestinal permeability are hormonal imbalances (e.g. hypothyroidism), taking certain medications (e.g. antibiotics, corticosteroids), and some neurological conditions (e.g. traumatic brain injuries). There is also evidence that genetics and how a person’s genes are actually expressed (epigenetics) play a large role in determining leaky gut susceptibility.

For example, Dr. Alessio Fasano, a pioneer in leaky gut research, has presented evidence suggesting that people with autoimmune diseases such as Celiac Disease have higher intestinal permeability (even in the absence of gluten) due to abnormal expression of a protein called zonulin. His research has revealed that zonulin is a key “gut gatekeeper” molecule, which when present at high levels (or in mutated forms) keeps the spaces between intestinal cells open, leading to persistently increased intestinal permeability.

Certain disease states and other conditions put people at an elevated risk for leaky gut. These include:

  • Autoimmune diseases like Celiac Disease, Lupus, RA, MS, Hashimotos Thyroiditis
  • SIBO or other microbial infection of the gut  Delivered by C-section
  • Immune compromised states like HIV/AIDS
  • High levels of chronic stress (physical or emotional)
  • Living in areas with toxic water, air, food, or general pollution
  • Traumatic injuries
  • Starving and malnourished
  • Prescription medications like antibiotics, corticosteroids, antacids, NSAIDS, etc.

Simplicity Nutrition practitioners focus on adding healing food into the diet coupled with proper supplementation to create a healing environment for the body to heal. We do not promote deprivation or extreme elimination of foods, unless absolutely necessary. The first step is to add the foods that help with some surface symptoms and also help the root cause. It is then, when  you will have the skills you need to be successful when removing a food that is not allowing the body to heal.

Given the multiple daily direct interactions between food and our intestines, it is not surprising that many foods have the ability to help heal leaky gut. For instance, some (this is not an extensive list) common food elements that have been shown to increase intestinal permeability include:

  • Gluten – Per Dr. Fasano, gluten has increased permeability in all research subjects they’ve tested!
  • Dairy products from cows – particularly Northern European black-and-white breeds such as Friesian and Holsteins that produce milk with mainly beta-A1 casein proteins
  • Unsprouted grains & soy
  • Unsoaked nuts & seeds
  • Nightshade vegetables & spices (e.g. tomato, white potatoes, chili peppers, paprika)

— On the flip side, there are foods and supplements that help fortify gut integrity such as:

  • High-quality Fish oil
  • L-Glutamine (talk with your Nutritionist for the right dosing)
  • Bone broth (from grass-fed animals)
  • Grass fed or pasture raised meat and eggs
  • Collagen (from grass-fed animals)
  • Vitamin D & K2
  • Healthy Fats

If you suspect that you are at risk or may be suffering from leaky gut we strongly suggest that you make an appointment to learn more about the condition, get the proper tests, address your potential root causes, and to receive an individualized plan to heal yourself with nutrition and lifestyle modifications.

Let our team at Simplicity Nutrition empower you with the knowledge, skills, and help to individualize your plan based on your unique body to re-build healthy boundaries and reclaim your well-being!



Campbell AW. Autoimmunity and the gut. Autoimmune Dis. 2014;2014:152428.!po=33.7838

Fasano, A. Clinic Rev Allerg Immunol (2012) 42: 71. doi:10.1007/s12016-011-8291-x

Foroutan, Robin. DIFM Newsletter. Zonulin: The Gateway to Leaky Gut. Summer 2013.

Pathophysiological mechanisms of stress-induced intestinal damage. Curr Mol Med. 2008 Jun;8(4):274-81.

Stimulating the central nervous system to prevent intestinal dysfunction after traumatic brain injury. J Trauma. 2010 May;68(5):1059-64

Sturgeon C, Fasano A. Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue Barriers. 2016;4(4):e1251384.

Transcript of Interview with Alessio Fasano on Gluten, Autoimmunity and Leaky Gut. August 2012.

Woodford K, (2007). Devil in the Milk: Illness, Health, and Politics: A1 and A2 Milk. Wellington New Zealand: Craig Potton Publishing.


© 2017 Simplicity Nutrition. Inc.

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