There are two closely related variables that determine our gut health: the intestinal microbiota, or “gut flora”, and the gut barrier. Let’s discuss each of them in turn.
The gut flora: a healthy garden needs healthy soil
Our gut is home to approximately 100,000,000,000,000 (100 trillion) microorganisms. That’s such a big number our human brains can’t really comprehend it. One trillion dollar bills laid end-to-end would stretch from the earth to the sun – and back – with a lot of miles to spare. Do that 100 times and you start to get at least a vague idea of how much 100 trillion is.
The human gut contains 10 times more bacteria than all the human cells in the entire body, with over 400 known diverse bacterial species. In fact, you could say that we’re more bacterial than we are human. Think about that one for a minute.
We’ve only recently begun to understand the extent of the gut flora’s role in human health and disease. Among other things, the gut flora promotes normal gastrointestinal function, provides protection from infection, regulates metabolism and comprises more than 75% of our immune system. Dysregulated gut flora has been linked to diseases ranging from autism and depression to autoimmune conditions like Hashimoto’s, inflammatory bowel disease and type 1 diabetes.
Unfortunately, several features of the modern lifestyle directly contribute to unhealthy gut flora:
- Antibiotics and other medications like birth control and NSAIDs
- Diets high in refined carbohydrates, sugar and processed foods
- Diets low in fermentable fibers
- Dietary toxins like wheat and industrial seed oils that cause leaky gut
- Chronic stress
- Chronic infections
Antibiotics are particularly harmful to the gut flora. Recent studies have shown that antibiotic use causes a profound and rapid loss of diversity and a shift in the composition of the gut flora. This diversity is not recovered after antibiotic use without intervention.
We also know that infants that aren’t breast-fed and are born to mothers with bad gut flora are more likely to develop unhealthy gut bacteria, and that these early differences in gut flora may predict overweight, diabetes, eczema/psoriasis, depression and other health problems in the future.
The gut barrier: the gatekeeper that decides what gets in and what stays out
Have you ever considered the fact that the contents of the gut are technically outside the body? The gut is a hollow tube that passes from the mouth to the anus. Anything that goes in the mouth and isn’t digested will pass right out the other end. This is, in fact, one of the most important functions of the gut: to prevent foreign substances from entering the body.
When the intestinal barrier becomes permeable (i.e. “leaky gut syndrome”), large protein molecules escape into the bloodstream. Since these proteins don’t belong outside of the gut, the body mounts an immune response and attacks them. Studies show that these attacks play a role in the development of autoimmune diseases like Hashimoto’s and type 1 diabetes, among others.
In fact, experts in mucosal biology like Alessio Fasano now believe leaky gut is a precondition to developing autoimmunity:
Source Reference:: Chris Kresser M.S., LA.Ac