We are learning increasingly more about the intestinal tract and its impact on overall health. In 2000, Dr. Alesso Fasano, Director of the Mucosal Immunology and Biology Research Center at Massachusetts General Hospital in Boston, discovered a gut protein that regulates the openings between the cell walls and the intestine; this protein is called zonulin(1). Zonulin can widen or tighten openings in the intestinal wall thus altering what nutrients and substances can permeate into the cells. Thus, zonulin can regulate the permeability of the gut.
The term Leaky Gut Syndrome is used to describe the condition of hyperpermeable intestines, a fancy medical term that means the intestinal lining has become more porous, with more holes developing that are larger in size and the nutrient screening process is no longer functioning properly(2). When the GI tract lining is functioning at its best, it is a tight barrier that controls what gets absorbed into the bloodstream. Larger than normal openings (i.e. fissures) within the intestinal wall, allows partially digested food, toxins, and gut microbe to enter the blood stream; triggering an immune response (systemic inflammation) and altering the gut microbiome.
Leaky Gut Syndrome has been associated with many autoimmune diseases. We already know that increased intestinal permeability plays a role in certain gastrointestinal conditions such as Celiac Disease, Crohn’s Disease, and irritable bowel syndrome (IBS)(3). The biggest question is whether a leaky gut can cause problems elsewhere in the body (3). Some studies show that leaky gut may be associated with other autoimmune diseases (Lupus, Type 1 Diabetes Mellitus, Multiple Sclerosis, Thyroiditis), Chronic Fatigue Syndrome, Fibromyalgia, Arthritis, Allergies, Asthma, Acne, Obesity and even Mental Illness (such as Alzheimer’s disease) (3,4)
What Causes Leaky Gut Syndrome? Obviously, more research is needed, and many researchers feel we are just starting to scratch the surface of understanding the complete role of the gastrointestinal tract and its impact on overall health. There are many factors that are thought to contribute to someone having a leaky gut. Diet, medications, infection, stress, hormone imbalance, environmental, Vitamin D deficiency and low glutathione levels are all suspect. Let’s look at these individually: Diet – The U.S. diet is highly processed and lends itself to many culprits that can permeate the intestinal single layer wall such as gluten, casein (cow’s dairy), sugar, unsprouted grains and alcohol. Many people with autoimmune diseases find themselves with leaky gut and having to eliminate certain foods to manage their conditions.
Medications – the biggest culprits in the pharmacotherapy world are antibiotics and acid reducers. Both create dysbiosis which lends itself to creating SIBO (small intestinal bacterial overgrowth and SIFO (small intestinal fungal overgrowth). Seventy-eight percent of IBS patients test positive for SIBO.
Infection – 75-80% of the immune system resides in the GI tract. When a body gets an infection, this can create dysbiosis within the microbiome. There are numerous studies that have demonstrated the intimate relationship between infection and dysbiosis of the microbiota and have shown that infection is associated not only with the microbiome, but also with viruses(5).
Stress – stress has shown to have an impact on microbiota. A study conducted at Oregon State University in 2017 by Jesse R. Zaneveld et. al. found that when a person is under stress, his or her microbiome will become confused and behave erratically in ways that are unpredictable and can vary from person to person(6).
Hormone Imbalance – Of the 50 million Americans living and coping with autoimmune disease (AD), more than 75 percent of them are women(7). Some researchers do not think this is a coincidence but an association with fluctuating hormone levels throughout the lifespan of women; more research is needed.
Environmental Factors – The infant GI tract is colonized with microorganisms in a complex process that begins during birth(8)¸. Babies delivered vaginally will show different microbial profiles than those babies delivered via C-section(8). When a child reaches the age of one, their GI tract starts to look more like the microbiota profile of an adult. However, children are not being exposed to enough microbes in countries where there is a high level of hygiene. Thus, children’s immune systems may not be developing to their full potential.
Vitamin D Deficiency – Research is finding that a Vitamin D deficiency is associated with many different malabsorptive conditions such as Celiac disease, Short Bowel Syndrome and Cystic Fibrosis however, other conditions and factors also contribute to Vitamin D deficiency such as obesity, diet, inadequate sun exposure, and some prescription medications. Vitamin D deficiency decreases the production of defensins which are anti-microbial molecules essential to maintaining healthy gut flora(9).
Low Glutathione levels: The gut microbiome regulates the synthesis of glutathione. If dysbiosis is present, less glutathione will be produced. Glutathione is the body’s main antioxidant and it is important for fighting of infections and disease.
Treatment Modalities for Leaky Gut:
Currently there are no medications to treat leaky gut syndrome. Diet is the primary defense for healing a leaky gut. Fecal transplants have also been used to treat certain IBS conditions. A fecal transplant is where clean stool is taken from a healthy GI tract and placed into a diseased GI tract to repopulate good bacteria. In the United States, fecal transplants are currently being used on Ulcerative Colitis patients and in Europe and other countries, fecal transplants are being used to treat Multiple Sclerosis.
There are several foods and supplements that have been proven to help heal a leaky gut:
1. Bone broth – making soup out of chicken and/or beef bones provides some liquid rich in the amino acids proline, glycine and L-glutamate. These are paramount in the healing process.
2. Kefir or Homemade Yogurt (fermented for at least 24 hours) – fermented dairy products have a high level of Lactobacillus. Probiotics introduce good bacteria back into the microbiome.
3. Fermented Vegetables (sauerkraut, kimchi, kvass) – the pH level of these fermented vegetables provides a perfect environment for good bacteria to flourish. They also provide Bacillus subtillis and Lactobacillus plantarum; two probiotics that favor a balanced gut flora.
4. Coconut products – especially coconut oil. Coconut oil has a natural anti-microbial property to it, thus killing off bad bacteria. Coconut oil is also a medium chain triglyceride and it is easy to digest.
5. Wild-Caught Fish (not farmed) such as Salmon, Mackerel and Tuna. These fatty fish species are high in omega 3 fatty acids which are anti-inflammatory and help with systemic inflammation.
6. Sprouted Seeds – Flax, Chia and Hemp Seeds. A major benefit to the sprouting of seeds is to release beneficial enzymes which make digestion easier. They also lend themselves to increasing good bacteria in the gut to help lessen the auto-immune response of bad bacteria.
7. Fresh or steamed vegetables – vegetables of all types provide beneficial substances such as phytochemicals, fiber, antioxidants and more!
8. Vitamin D supplementation (if warranted) – The Vitamin D Council recommends a serum vitamin D Council recommends a serum vitamin D25-OH level of at least 40 ng/ml (40-80 ng/ml) for optimal health. The richest source of Vitamin D is 2 tablespoons of cod liver oil (1300 IU per Tbsp) which many people no longer purchase and use due to its foul taste. A supplement of 2,000 IU per day is typically needed to get a serum level of Vitamin D-25-OH above 40 ng/ml if a deficiency is present.
Although Leaky Gut Syndrome can be healed, the genesis of this syndrome warrants more research, as well as the essential role that the gastrointestinal tract plays in overall health and well-being.
1. “Zonzulin and Its Regulation of Intestinal Barrier Function: The Biological Door to Inflammation, Autoimmunity and Cancer. Alessio Fasano. American Physiological Society 91: 151-175, 2011.
2. “Leaky Gut, Autoimmune Disease and Diet” Ginger Schrimer PhD, RD. ceinternational.com March 27, 2018
3. “Leaky Gut: What Is It, and What Does It Mean For You? Marcelo Campos MD. www.health.harcard.edu/blog/leaky-gut-what-it-is-and-what-does-it-mean-for-you?
4. “Gut Reaction: Environmental Effects on the Human Microbiota” Melissa Lee Phillips. Environmental Health Perspectives Vol 117, No 5, May 2009
5. “The Human Microbiota in Health and Disease” B Wang, M Yao, L Lv, Z Ling, L. Li. Elsevier Inc. 2017.
6. “Chronic Stress Discombobulates Gut Microbiome Communities.” Christopher Bergland Psychology Today. August 25, 2017.
7. “Leaky Gut Syndrome: What Is It? Matt McMillen www.Webmd.com
8. “Vitamin D Improves Gut Flora ad Metabolic Syndrome”
9. “How Does Age at Onset Influence Outcome of Autoimmune Diseases? M. Amador-Patarroyo, A. Rodriguez-Rodriguez, G. Montoya-Ortiz. Autoimmune Diseases Vol. 2012, Article ID 251730, 2011.
10. “The Microbiome: A Key Regulator of Stress and Neuroinflammation” K. Rea, T. Dinan, J. Cryan Elsevier Inc. 2016.
11. “Is Leaky Gut Syndrome Real and Can Probiotics Help?” Markham Heid. Time.com→Health→Medicine. January 13, 2016.
12. “Possible Links Between Intestinal Permeability and Food Processing: A Potential Therapeutic Niche For Glutamine.”J. Rapin, N. Wiernsperger Clinics 2010:65 (6): 635-43.