Provider Practice Essentials registered nurse continuing education

A Root of Evil: Increased Intestinal Permeability

I was going to start this blog post on intestinal permeability with a patient scenario but decided against it. Because there are SO many different diseases and conditions that research has shown link back to increased intestinal permeability, I couldn’t choose one to start with.

The following are just a few of the known conditions related to increased intestinal permeability:

  • Inflammatory bowel disease
  • Irritable bowel syndrome
  • Celiac disease
  • Food sensitives/intolerances
  • Fatigue
  • Mental disorders: major depression disorder, anxiety, etc.
  • Obesity
  • Type 2 diabetes
  • Parkinson disease
  • Alzheimer’s disease
  • Autism spectrum disorders

What is increased intestinal permeability?

Your gastrointestinal tract breaks down what you eat and drink. The intestinal wall also absorbs nutrients and fluids for your body to function. This is just like putting gasoline in your vehicle. In a perfect world, the intestinal wall acts as a barrier to infection in addition to absorbing nutrients and water. This prevents the body from absorbing harmful substances (toxins and bacteria) that pass through the intestine. Think of the intestine wall as a checkpoint, if you’re good you may enter, if you’re bad you may not enter.

The intestine wall needs to be in tip-top shape in order to have this fine balance of letting the good in and keeping the bad out. A very common breakdown in this system is an increase in the intestine wall permeability, some also refer to it as a leaky gut. There’s been a breakdown in the intestinal wall barrier at some point and the “bad” starts entering the body where it shouldn’t, the wall is also more “permeable”. This is a simple explanation of how this barrier works, just be aware that the intestinal wall is extremely complex in how it functions.

How does one determine increase intestinal permeability?

Currently, there is no gold standard for determining intestinal permeability. Testing can be done utilizing intestinal tissue, fecal markers or intestinal biomarkers in the blood. A combination of tests help to obtain the most accurate results.

Commonly tested fecal markers include alpha 1-antitrypsin, myeloperoxidase and calprotectin. These markers detect neutrophil activity and can help identify inflammation in the gut.

Biomarkers are measurable substances in the blood that can be indicative of a disease/illness or infectious process in the body. Common biomarkers that are measured to assess for increased intestinal permeability are zonulin, intestinal-fatty acid binding proteins (I-FABP), citrulline, glucagon-like peptide 2 (GLP-2), lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP), diamine oxidase and alpha 1-antitrypsin.

There isn’t one biomarker that is specifically preferred over another. As each biomarker tells its own story and looks at different threats against the gastrointestinal tract. For instance, LPS is indicative of gram-negative bacteria that could have attacked the intestinal wall. Whereas, zonulin is a protein responsible for regulating the tightness of the cell junctions within the intestinal wall. If zonulin isn’t regulated, which can be caused by something as simple as chronic stress, then inflammation and autoimmune disorders can evolve. Evaluating the biomarkers can be helpful in determining the cause of increased intestinal permeability but just know the results can have a broad meaning and are only a piece to the puzzle.

How to treat Increased Intestinal Permeability?

Well, due to the fact that it can be difficult to pinpoint the exact cause of increased intestinal permeability it is often times difficult to treat increased intestinal permeability. A safe, foundational treatment for any cause on increased intestinal permeability includes a prebiotic and probiotic to help heal the gut. In addition to this, if the individual is dealing with chronic stress, then stress management is also crucial in healing the gut.

Research is ongoing in this field of medicine and will be for quite some time; there is still so much to learn. The human body is truly fascinating! As the famous Greek physician, Hippocrates, once said “all disease begins in the gut.”


Schoultz, I., & Keita, Å. V. (2020). The intestinal barrier and current techniques for the assessment of gut permeability. Cells, 9(8), 1909.

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