Leaky Brain, Leaky Gut: The Real Mind-Body Connection

Contents hide

1 What Is Leaky Brain

2 Conditions Associated With Leaky Brain

3 Leaky Gut: The Culprit

4 How Leaky Gut Leads To Leaky Brain

5 Causes of Leaky Gut

6 Gut-Brain Tight Junctions and Adherent Junctions

7 How Leaky Gut Helps Toxins Cross The Blood-Brain Barrier

8 Leaky Brain, Leaky Gut Functional Tests

9 The Vagus Nerve: The Real Gut/Brain Axis

10 How To Heal Leaky Brain

11 Leaky Gut/Leaky Brain Diet

12 Foods To Avoid To Heal Leaky Gut/Leaky Brain

13 Supplements That Help Leaky Brain/Leaky Gut

14 Biohack Your Brainpower

The mind-body connection is real.

This once-fringe concept is now being exposed by scientists researching the gut and its direct connection to the brain.

Brain-Gut connection. What happens in the gut affects the brain

Many experts still consider this research to be in its infancy,

However, one conclusion seems to be clear.. what happens in the brain directly reflects what is happening in the body.

One of the most glaring examples of this is the phenomenon of leaky brain and its relationship to leaky gut.¹

Leaky brain research indicates that it is a serious problem.

In fact, it may be at the heart of many mental health disorders.

However, it is encouraging to know that it is possible to heal a leaky brain by rebuilding the integrity of your gut.

This means that healing your gut could be a promising method to optimize your mind.

In this article, I’ll give an overview of what leaky brain is, how it relates directly to problems with the gut, why I believe it to be so prevalent in our modern culture, and steps you can take to optimize your brain by healing your gut.

What Is Leaky Brain

The blood-brain barrier is your brain's security guard — The blood-brain barrier is your brain’s security guard

Leaky brain is the end result of a complex breakdown in the blood-brain barrier commonly referred to as blood-brain barrier permeability.²

A functional blood-brain barrier is essential to maintaining central nervous system homeostasis.

The Blood-Brain Barrier

The blood-brain barrier (BBB) separates the central nervous system (CNS) from the peripheral tissues of your body.

It’s effectively a security checkpoint that keeps harmful toxins and inflammatory mediators that can negatively affect neural function out of your brain.³

When the blood-brain barrier breaks down, the brain becomes exposed to molecules that may be toxic to vulnerable neurons in the hippocampus and elsewhere in the brain.

Conditions Associated With Leaky Brain

Leaky brain connection has been implicated in a number of psychiatric disorders⁴including:

Chronic disease numbers courtesy of the CDC

Leaky Gut: The Culprit

Of all the potential causes of disruptions in the blood-brain barrier, the most notorious might be leaky gut.¹³

If you’ve spent any time sifting through wellness articles online than you’ve probably come across this term.

Leaky gut, technically referred to as “intestinal permeability” occurs when there is dysfunction in the epithelial lining of the digestive tract.¹⁴

The lining of your GI tract is very thin and delicate making it susceptible to damage.

This dysfunction allows for certain proteins, lipopolysaccharide, and antigens to find their way outside of the digestive tract and into the intestinal mucosa where immunoglobulin A (IgA) antibodies are made.¹⁵

The immune system identifies these particles from the gut as foreign invaders and mounts a response.

This leads to increased inflammation throughout the body which has been tied to a number of chronic and autoimmune diseases.

How Leaky Gut Leads To Leaky Brain

The pro-inflammatory cytokines triggered by leaky gut eventually attack the tight junctions of the blood-brain barrier.

This results in compromised blood-brain barrier integrity and all the cognitive issues that follow.¹⁶

Leaky gut has been directly implicated in a number of cognitive disorders¹⁷ including:

Alzheimer’s
Dementia
Parkinson’s
Depression

Inflammation is the major disruptor of the BBB. Many diseases and physiological stressors that affect the CNS also alter the functional integrity of the BBB¹⁸

Causes of Leaky Gut

The lining of the human GI tract is very thin and quite vulnerable to damage.

There are a number of reasons why someone may experience gut permeability including:

Occasional exposure to one or even a few of these factors may not present such dire consequences.

However, in modern society, many people are exposed to excessive doses of one or more of these elements on a daily basis.

Which may be why diseases tied to leaky gut and leaky brain have become so prevalent.²⁵

And to make matters worse, the problem may be handed down generationally, leading to increases in childhood disorders and more compounded issues.²⁶

Gut-Brain Tight Junctions and Adherent Junctions

The similar construction of protective barriers in the gut and brain highlights an example of the intricate connection of these 2 organs.

Tight junctions in the gut mimic tight junctions in the brain

The gut and brain barriers are the ultimate security system, intelligently built to keep tabs on the flow of cellular information.

This is done through selective permeability regulated by tight junctions and adherent junctions that make up the endothelial cells of the barrier lining.²⁷

These junctions are joined by a number of specialized transporters, pumps, and receptors which aid in the flow of substances across the linings.²⁸

In the brain, selective transport proteins allow nutrients, oxygen, amino acids, some drugs, and glucose to enter the cerebrospinal fluid for metabolism in the brain.²⁹

In the gut, tight junctions once thought to be static, are in fact dynamic and readily adapt to a variety of developmental, physiological, and pathological circumstances.³⁰

When these tight and adherent junctions are working correctly, nutrients are better absorbed by the gut and brain which will optimize the function of both.

When these junctions are not working correctly you experience both leaky gut and leaky brain.

Zonulin

Circulating, serum zonulin is the main marker of gut permeability.³¹

Zonulin is a protein that acts as an endogenous modulator of epithelial tight junctions.

If tight junctions are the security guard, zonulin is the supervisor giving the orders.

It serves a number of functions including regulating the movement of fluid, macromolecules, and leukocytes between the bloodstream and the small intestine, and vice versa.³²

Zonulin also protects against microorganism colonization of the proximal intestine.³³

While acute low levels of zonulin are natural in a healthy gut, it seems that prolonged chronic exposure can be problematic.³⁴

Prolonged zonulin exposure is one of the main drivers of leaky gut and ultimately all the disorders that follow.

High levels of zonulin have been correlated to elevated inflammatory markers, obesity, metabolic disorders, and advanced cognitive aging.³⁵

The biggest triggers of excess zonulin production include bacteria and gluten.³⁶

LipoPolySaccharide (LPS)

Lipopolysaccharides are another contributor to inflammation associated with leaky gut.³⁷

Lipopolysaccharides are important outer membrane components of gram-negative bacteria that provide integrity to the bacterial cell and contributes to the interaction of these bacteria to other surfaces.³⁸

In a healthy gut, LPS concentrations mostly stay put in the gut lumen which houses many trillions of commensal bacteria.³⁹

In a leaky gut, tight junctions open in the presence of increased zonulin, and LPS is released into the bloodstream.

Once in circulation, LPS elevates inflammatory cytokines and the odds of chronic physical and mental disease.⁴⁰

Think of your gut like a tire, LPS like the air, and zonulin like a nail. When your gut tire is pierced by a zonulin nail, the LPS air is let out. The result is a flat tire and a broken-down car.

And much like the broken down car, in the presence of elevated LPS your body also begins to break down.

In fact, studies examining disease-free centenarians show a low presence of LPS and zonulin.⁴¹

How Leaky Gut Helps Toxins Cross The Blood-Brain Barrier

The release of lipopolysaccharide into circulation through a leaky gut produces a cascade of inflammatory cytokines that compromise the integrity of the blood-brain barrier.⁴²

Lipopolysaccharide itself can also induce blood-brain barrier permeability through phosphorylation of the cellular membrane protein, Cav-1.⁴³

This is yet another example of how important reducing LPS-induced Cav-1 phosphorylation is to protecting the integrity of the blood-brain barrier.

The best way to reduce LPS-induced Cav-1 phosphorylation is by lowering circulating LPS through healing gut permeability.

Cav-1 and the Blood-Brain Barrier

Cav-1, a well-established major structural protein of caveolae, has demonstrated an important role in the regulation of multiple cellular processes, including cell growth, differentiation, endocytosis, cholesterol trafficking, and cellular senescence.⁴⁴

It’s a part of the Caveolae family of integral membrane proteins and expressed mostly in the endothelial cells of the blood-brain barrier.⁴⁵

Like many other cellular proteins, there seems to be a homeostatic Goldilocks zone of expression. Not too much and not too little.

In the brain, cav-1 regulates neuronal signaling and promotes dendritic growth and predominantly regulates BBB permeability through transcellular and paracellular routes.⁴⁶

Changes in cav-1 can sequentially induce a series of alterations in BBB permeability, neuroinflammation, cerebral angiogenesis, apoptosis, and oxidative stress.⁴⁷

One of Cav-1’s most important jobs is inhibiting matrix metalloproteases (MMPs).

MMP-9 specifically, degrades tight junction proteins and ultimately the blood-brain barrier.⁴⁸

MMP-9 production is also highly influenced by inflammatory cytokines and LPS.⁴⁹

All of this underlines how important reducing LPS-induced Cav-1 phosphorylation is to protect the integrity of the blood-brain barrier.

The best way to reduce LPS-induced Cav-1 phosphorylation is by lowering circulating LPS through healing gut permeability.

Leaky Brain, Leaky Gut Functional Tests

Functional lab testing can help identify problems

Now that you know what a leaky brain is and how it’s connected to a leaky gut, it’s time to find out if this is your problem.

The best way to do this is through functional lab tests that can be ordered by a doctor or health practitioner.

These tests can give you insight into your levels of relevant issues that may be affecting your gut/brain axis. Below are some of the tests that may help you in this assessment.

Serum zonulin: Indicator of gut permeability
Serum lipopolysaccharide: Indicator of leaky gut and blood-brain barrier permeability
Cyrex Labs Array 20 blood-brain barrier permeability: Comprehensive lab test measuring immune system reactions
Serum Matrix Metalloproteinase-9 (MMP-9): Can tell you if your blood-brain barrier’s tight junctions are under attack.
Great Plains Labs Organic Acids Testing: Fully comprehensive metabolic marker panel that can indicate harmful gut bacteria and neurotransmitter production
Great Plains Lab Mycotox/Mold testing : Measure of mold toxicity circulating in your body that may trigger inflammation and ultimately BBB permeability
Great Plains Lab Environmental Toxin Testing: Measure of environmental chemicals that can cross a leaky blood-brain barrier and cause neurological issues.

The Vagus Nerve: The Real Gut/Brain Axis

Your vagus nerve is the main interface of the gut/brain connection.

It is a mixed nerve with anti-inflammatory properties both through its afferent and efferent fibers and is the principal component of the parasympathetic nervous system.⁵⁰

It literally connects your brain to your gut and thus highly influences the bidirectional connection.

A full functioning, highly optimized vagus nerve can

How To Heal Leaky Brain

The most effective way to heal a leaky brain is a multi-pronged approach of gut healing, stress reduction, and detoxification.

All 3 will help reduce gut permeability and inflammation while strengthening the integrity of the blood-brain barrier.

Regular movement, exercise, breathing, and mindfulness practices will help lower stress and boost BDNF and neurotransmitter production as well.

Leaky Gut/Leaky Brain Diet

A disciplined approach to diet is of the utmost importance when it comes to healing the gut.

Of course, this is easier said than done.

For many people, diet is what caused the onset of these conditions.

The good news is that many people are able to heal their gut and the associated brain issues with the right diet.

This may take some trial and error, but once you figure out what foods work best for you and which are your problem foods than you are well on your way to success.

Some diets that are known to help leaky gut/leaky brain include:

Low FODMAPs
GAPs
AIP (Autoimmune Paleo)
Wahl’s Protocol

Foods To Avoid To Heal Leaky Gut/Leaky Brain

To truly heal your gut you must eliminate all the low hanging problem foods that are known gut irritants. These include:

Adding in more nutrient-dense whole foods like organic fruits, vegetables, and high-quality animal products will give your body more healing nutrition.