Understanding The Cause of Leaky Gut

What really causes leaky gut and is it a true medical condition?

I have heard people talking about “leaky gut” for years. I’ve read multiple claims that “leaky gut” is the cause of a myriad of health problems. The idea is this: unwelcome substances leak out of the intestines and into the bloodstream, causing a reaction in the body. To be honest with you, I initially wrote it off as some made-up condition that had no merit in the medical field. However, the posts persisted, so I decided it was time to do some research.  The intestinal wall is made of a layer of cells that are specifically designed to have maximum absorption of nutrients. But, can the gut “leak”?These statements have not been reviewed by the FDA and are not intended to cure, diagnose, treat, or prevent any medical condition. This is my own personal research.

Here’s What I Found

The medical term for a “leaky gut” is actually intestinal hyperpermeability.

Intestinal (the gut)

hyper (too much)

permeability (leaking).

leaky gut | what causes leaky gut | leaky gut and inflammation

To understand this, we need to go back to the basic anatomy and physiology of the human gastrointestinal (GI) tract. The GI tract is, in a very basic sense, just one long tube that makes some twists and turns here and there. Ultimately, food will go in one end and come out the other. Leaking happens in between, specifically, in the intestines.

Digestion begins in the mouth and continues in the stomach where food is broken down chemically (2). While the stomach is mostly concerned with digestion, the small intestine is home to both digestion and absorption.

Digestion- biochemical break down food into much smaller molecules

Absorption-the process by which the cells allow those molecules into the body

The pancreas joins in to do a little more digestive work in the upper small intestine (duodenum) by releasing different enzymes specific for carbohydrates, proteins, and fats. (2) In the middle small intestine (jejunum), the body starts to absorb.

The cell lining of the intestinal tract is a barrier that separates the external environment from the body fluids and blood. There is a single and continuous layer of cells that form a barricade between the inner space of the gut and the bloodstream/body fluids (1). These cells form a close-fitting junction with each other, but the space between cells holds the potential for unregulated movement of unwanted substances, or solutes (1). This, however, does not happen in a healthy GI tract. A properly functioning cell lining includes two lock-like junctions between cells that regulate the movement of solutes (1).

leaky gut | what causes leaky gut | leaky gut and inflammation

In an experiment performed in the 1990s, pieces of cell wall from normal gut bacteria were injected into the cell lining of rat colons. This action led to localized (at the injection site) and systemic (body-wide) inflammation (1). When solutes from the gut were directly injected from the body tissue, there was an inflammatory response.

Carbohydrates, proteins, and fat are absorbed through the cell, not in between cells. The cells create a passageway for the carbs and proteins to be absorbed into the bloodstream and send these two nutrients straight to the liver (2). Fats are absorbed directly into the cell, with no passageway required, and then into the lymphatic system–bypassing the liver (2). The big difference here is that nutrient particles are absorbed into the cell lining during a physiological process performed by a healthy body, while harmful solutes pass in between the cells and only when the gut lining is not functioning as it should. Why does this happen? The junctions between epithelial cells are an ever-changing system that responds to gut bacteria, diet, hormones, chemical signals, environmental changes, inflammatory agents, and microbial or viral disruption (1).

 leaky gut | what causes leaky gut | leaky gut and inflammation

This process is very complex and will require more research to be fully understood. The cell lining of the gut is dynamic. However, we do know that when it becomes irritated, the intestinal wall can become more permeable than usual. What irritates the intestinal wall? The substances we ingest, our hormones, stress, environmental factors, and a disrupted intestinal flora may all lead to an abnormal permeability of the intestinal lining. As stated learned earlier, this may contribute to an inflammatory response in the body–hence “Leaky Gut”!*



(1) Alterations in Intestinal Permeability

(2) Overview of Gastrointestinal Function

Please consult a doctor before making any health changes, especially if you have a specific diagnosis or condition. The information on this site should not be relied upon to determine diet, make a medical diagnosis, or determine treatment for a medical condition. The information on this website is not intended to be a consult with a healthcare provider. Any statements or claims about the possible health benefits from food or supplements have not been evaluated by the Food & Drug Administration (FDA) and are not intended to diagnose, treat, prevent or cure any disease. Full disclaimer here.


About Emily

Hi, I’m Emily. I’m a free range mama helping women conquer simple, healthy living with a side of science!

8 comments on “Understanding The Cause of Leaky Gut

  1. You are indeed a gifted scientist!! Keep it up. This is informative and useful information in a format that all can understand!!

  2. I totally thought leaky gut was made up as well. I’m so glad I did the research. I love how you made this so easy to follow and understand.

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