Reversing Leaky Gut: The Key to Healing IBD?
What is leaky gut, and how does it contribute to the development—and healing—of IBD symptoms?
What is leaky gut?
For people with inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, “leaky gut” has likely become a familiar term. This refers to the condition of the intestines in which the epithelial lining becomes more permeable, allowing exterior antigens (such as pathogens, toxins, undigested food particles, and bacteria) to pass through the lining and enter the bloodstream.
When toxins enter the body through a leaky gut, this may cause allergic reactions or infections that prompts the body to issue immune and inflammatory responses.
What causes leaky gut?
The human intestine is a highly complex organ covering an impressive 400 meters of surface area, protected by the barrier provided by the epithelial lining.
Along the length of the intestines, the lining must be permeable enough for the absorption of nutrients to the bloodstream—but at the same time, it also must also prevent a variety of toxic substances from entering the bloodstream. A healthy intestine contains several mechanisms that form a specialized barrier to block toxins while absorbing nutrients.
Impressively, the first line of defense consists of a physical barrier maintained by a single layer of epithelial cells. These cells (which include enterocytes, goblet cells, Paneth cells, microfold cells, enteroendocrine cells, cup cells, and tuft cells) are linked together by proteins called tight junction, or TJ, proteins. The pathway between the epithelial cells are sealed by the TJ proteins, allowing substances to be transported through the spaces between cells in what is called a paracellular pathway.
This physical barrier is one of several barriers to prevent antigens from entering the bloodstream—the intestine is also host to biochemical and immunological barriers, and if an abnormality occurs in any one of these barrier functions, leaky gut can occur.
Researchers have pointed to a large number of contributing leaky gut causes. These including an imbalance of microorganisms in the gut, damage to the mucosal lining, diet and food ingredients, infections, alcohol consumption, and burn injury.
Diseases linked to leaky gut
Leaky gut is not only linked to diseases in the gastrointestinal tract like Crohn’s and colitis. Leaky gut may contribute to multiple autoimmune diseases: IBD, celiac disease, autoimmune hepatitis, type 1 diabetes (T1D), multiple sclerosis, and systemic lupus erythematosus (SLE).
Research indicates that, in people who are genetically predisposed to these autoimmune diseases, a leaky gut may permit environmental factors to enter the body, triggering the development of the disease.
Reversing leaky gut: a therapeutic strategy
Because intestinal permeability is thought to be a contributing factor to the development of autoimmune diseases, researchers have hypothesized that regulating intestinal permeability may be an effective strategy for treating these autoimmune conditions.
In a 2017 scientific review published in Frontiers in Immunology, the authors reported that there is increasing evidence to suggest that intestinal barrier dysfunction is an important causative element for autoimmune disorders. The authors of the review concluded that reversing leaky gut appeared to be an attractive therapeutic strategy for treating the autoimmune diseases that have been linked to leaky gut.
Healing the intestinal lining
Healing the intestinal lining is a critical step in IBD treatment. Healing the lining reduces permeability, restoring proper barrier function that blocks toxins in the intestine from circulating through the body in the bloodstream.
Gastroenterologists, researchers, biopharmaceutical companies, and patients have looked to multiple methods for healing the intestinal lining, including probiotics, antibiotics, medications, food supplements, and more.
One of the latest products for healing the intestinal lining is currently being developed by Prometheus Labs. The researchers at Prometheus are investigating a protein-rich supplement drink called CROWN, measuring the benefits it provides as a Crohn’s disease treatment in healing the intestinal lining. Recent studies on dietary protein and mucosal healing have found evidence to suggest that dietary protein may help heal the intestinal lining. Click here to see if you’re eligible to participate in a CROWN clinical trial in your area.
Rutgeerts, P., Vermeire, S., & Van Assche, G. (2007). Mucosal healing in inflammatory bowel disease: impossible ideal or therapeutic target? Gut, 56(4), 453–455. Retrieved from http://doi.org/10.1136/gut.2005.088732
Vidal-Lletjós, S., Beaumont, M., Tomé, D., Benamouzig, R., Blachier, F., & Lan, A. (2017). Dietary Protein and Amino Acid Supplementation in Inflammatory Bowel Disease Course: What Impact on the Colonic Mucosa? Nutrients, 9(3), 310. Retrieved from http://doi.org/10.3390/nu9030310
Mu, Q., Kirby, J., Reilly, C. M., & Luo, X. M. (2017). Leaky Gut As a Danger Signal for Autoimmune Diseases. Frontiers in Immunology, 8, 598. http://doi.org/10.3389/fimmu.2017.00598