A Deeper Dive In Understanding Intestinal Permeability (or Leaky Gut)

  Art adapted from goodfoodeating.com

Art adapted from goodfoodeating.com

Written by Carla Alpert

Mucosal surfaces exist all over the body, such as the in the nose, the throat, eyes and GI tract. When we’re talking about Mucosal Barrier here, we’re talking about the small intestine and the lining of the small intestine. It connects the stomach and large intestine and believe it or not, it runs about 22 feet long and is only as big around as a middle finger. It handles most of the digestive process and absorbs about 90% of the nutrients from the food we eat. When functioning well it absorbs and transports necessary water, nutrients, and vitamins into our cells.

The graphic here, is the anatomy of the Mucosal Barrier of the small intestine. It’s lined with cells called Enterocytes, and they make up the barrier. They are held together by very tight junctions to keep particles from getting through. There are also little finger like things on the surface called villi, and they absorb the nutrients we need to thrive.

The job of the Mucosal Barrier is to make sure it contains the bad guys within it’s walls, while allowing the nutrients to pass through and nourish our bodies. It takes the macro nutrients (carbs, proteins and fats) we digest, and converts them to micro-nutrients small enough so they can be absorbed by the villi and deliver the nutrients we DO need, into our blood and cells to keep us vibrant and healthy.

So nothing should be absorbed into the blood stream that’s not broken down to a micro-nutrient size. Anything that’s larger should not be able to get through. You can see this on the chart.

As well as this physical barrier we also have a chemical barrier here. It’s created in the small intestine and it’s called Secretory IGA or "sIgA". This is our first-line of defense against gut pathogens like bacteria, food proteins, parasites, fungi, toxins and viruses. It’s there as a defense system to create antibodies and protect against these pathogens getting into the system. This addition barrier works well when the gut is healthy.

So we have these two major barriers that work together to protect us from toxins getting into our system.

It’s a very important function in the body and if it’s not functioning well, you can imagine what can go wrong. It can compromise our nutrient absorption as well as allow toxins to leak into the blood stream.

The following graphics show us the progression of the Mucosal Barrier break down, which is called Intestinal Permeability or Leaky Gut and the symptoms that can correlate. So at the top of the left chart you see you have stress, toxins, foods particles, drugs, pathogens and even a malfunction of an organ (like a liver as shown).

 Graphics from DrAxe.com

Graphics from DrAxe.com

If all of these, or one of these, are present on a consistent basis it can trigger inflammation and damage to the barrier.  Then we get a breakdown to the tight junctions between the Enterocytes, and little holes allow toxins and pathogens to leak through. It’s sort of like cheese-cloth. It will allow small particles to pass through, but if it’s torn, large molecules can also get through.

Then when these large particles leak through this barrier (cheese cloth) into the blood stream, the immune system goes on high alert. It recognizes the particle as a foreign object that shouldn’t be there and turns on an immune response.

So for example if a large food particle gets through (even a healthy food like an almond), your immune system recognizes it as an invader and tags it. So now any time that food is eaten, your immune system sees it as a dangerous invader and attacks it again, which causes more inflammation. That inflammation contributes to the breakdown of the mucosal barrier. This results with varied food intolerance's because food particles that are not supposed to be there, are leaking through into bloodstream. This is also true of gut pathogens and infections. This breakdown of the gut can also lead to immune issues and even autoimmune disease.

So now we end up with all these invadors which are creating inflammation to the barrier.  Then the villi that absorb the micro-nutrients can actually shrink and become blunted and flattened out. Because the villi are responsible for absorption of vital nutrients, if it’s flattened and gets diminished mal-absorption and mal-nutrition can occur.

Even the greatest healthy foods that you ARE eating don’t get absorbed.

Taking a look at the chart above right, you can see how Leaky Gut can lead to the symptoms throughout the whole body. Leaky Gut can cause obvious symptoms of gut distress like heartburn, bloating, cramping and bowel irregularities, but can also show up throughout the whole body. It's not always so obvious.

If you think Leaky Gut could be contributing to your chronic health issues and would like to talk more about it, contact me for a free consultation