Zonulin Test




What is Zonulin and Leaky Gut?

Zonulin is a protein enzyme in the gut that regulates the tight junctions between the mucosal barrier cells. When zonulin levels increase, the tight junctions become dysregulated, allowing unhealthy substances to migrate through the gut wall and infiltrate the bloodstream. This is called Leaky Gut.

Causes of elevated Zonulin and development of Leaky Gut
1- Overgrowth of harmful organisms, like bacteria or yeast in the intestine.
  • SIBO: Small Intestinal Bacterial Overgrowth
  • Fungal dysbiosis or candida overgrowth
  • Parasite infections
2- Gliadin in the diet (Gluten containing foods)


Effects of elevated Zonulin and development of Leaky Gut
As the zonulin level rises, the seal between the intestinal cells diminishes, opening up spaces between cells that allow all sorts of things to pass right through. Sometimes large food molecules will pass through to the immune system. The immune system thinks they are foreign invaders and will mount an immune response leading to food sensitivities. In addition, this immune activation leads to more damage of the intestinal cells (called enterocytes) and the gut becomes more inflamed and more permeable or "leaky”. As the damage continues, the microvilli that line the intestines and absorb nutrients become damaged, leading to other nutrient deficiencies.
Associations to elevated Zonulin and of Leaky Gut
1- Crohn's Disease
2- Type I Diabetes
3- Multiple Sclerosis
4- Irritable Bowel Syndrome (IBS)
5- Inflammatory Bowel Disease (IBD)
6- Obesity
7- Asthma
8- Metabolic Syndrome
Testing for Zonulin
Zonulin test requires single stool collection as a sample for this test although some might test Zonulin antibodies in the blood.