Leaky Gut Explained
“Leaky gut” is a pet name for intestinal hyper-permeability, a condition in which the normal tightly sealed barrier between the insides of your gut and the rest of your body is compromised.
Before you start imagining your lunch floating around inside your body, let’s talk scale. As you can gather from the gut anatomy photo below, the barrier that we are talking about here is exceedingly small; triple-zoomed-in, blow-your-mind small. So keep in mind as we talk about leaky gut that the leak is between two single cells (pictured far right below) that are each a lot smaller than the diameter of a single hair.
The junctions formed between these cells of this single-celled wall are the ones that are compromised in leaky gut. They’re aptly named “tight junctions” because a slew of proteins work hard to permit only water, ions, and small nutrients to pass through this space that connects the outside world to your organs and tissues. Remember we’re shaped like donuts. Everything else, including normal and foreign microbes, toxins, and food destined to be food or waste is kept out of this space. (1) Risk factors for leaky gut all disrupt the mission of these proteins in one way or another, so that they would be better called “loose junctions”. The once-tight-now-loose junctions let things pass more indiscriminately. The body doesn’t sit by quietly while microbes, their metabolites, and food antigens that are meant to live inside the gut are suddenly on the other side of the wall. (2, 3)
Symptoms of Leaky Gut
Bacteria, viruses, food (in the form of nutrients), toxins, and other materials were meant to travel around your body and between compartments, but they weren’t designed to travel in between the spaces of cells like is seen in leaky gut. This exposes them in an unexpected context to the immune, neuroendocrine, and circulatory systems on the other side of the single celled barrier. These are body wide systems so the commonly reported symptoms of leaky gut can pop up anywhere.
The Autoimmune Connection
The prevailing theory here is molecular mimicry. That’s what happens when one molecule (for example gluten) looks a lot like another molecule (for example a protein in the small intestine) and activates the immune system. In an effort to right the ship, the immune system ends up attacking normal healthy tissue (as in celiac disease). When the immune system attacks its host like that it’s called autoimmune disease. There is strong evidence that copy-cat pieces of protein in infectious microbes play a role in igniting autoimmune diseases like Type 1 Diabetes, Multiple Sclerosis, and Psoriasis because they look like pancreatic, nerve, and skin cells respectively. (4) There is growing evidence that similar copy-cat proteins are present in common foods like milk and wheat, suggesting an explanation for specific foods causing such nasty flares in other autoimmune conditions. (3)
Leaky gut is the perfect condition to facilitate molecular mimicry. When the gut barrier is compromised, food and microbes happen into situations they shouldn’t be in. The immune system is very sensitive to that, and this is likely one of the situations where the immune system is misinformed about who’s friend and who’s foe.
What causes leaky gut?
There are many risk factors for developing leaky gut, but the most common are a crappy diet, chronic stress, and the overuse of common drugs like ibuprofen and antibiotics. (5) Sounds like the standard American life unfortunately!
We’ll look at the causes and treatments for another day, but for now two things that jump out at me as common among these.
2. All these risk factors involve behavioral choices and for the most part are totally within our control.
I think it’s great news that by taking steps to clean up our diet and lifestyle, we can eliminate most of the risk factors that would put us in the messy situation of leaky gut. The treatments for complex disease don’t have to be complex.
Please let me know your comments, questions, and suggestions for future topics in the comments below!