Leaky gut = Leaky brain?

“Every man can, if he so desires, become the sculptor of his own brain.”
— Santiago Ramón y Cajal (Spanish physician, Nobel Prize in Medicine, 1906)

Did you know that damage to the barrier protecting our brain is more often caused by our dietary habits than by brain trauma?

Recently, we had the opportunity to attend this year’s International Conference on Functional Medicine, titled:
“The Dynamic Brain: Revealing the Potential of Neuroplasticity to Reverse Neurodegeneration.”

If you have no idea what neuroplasticity means, we invite you to read our article in honor of World Alzheimer’s Day: How to Prevent Alzheimer’s Disease?

Main Takeaways from the Conference

1. The brain is a moldable organ.
   It adapts to the stimuli it receives, meaning that many brain areas can be stimulated to promote regeneration.
2. The most significant influence is environmental.
   Beyond globally recognized factors like age, trauma, and genetic alterations, others such as diet, toxin exposure, and lack of cognitive stimulation strongly affect brain function.
3. Reversing — not just preventing — neurodegeneration.
   Modern research is focusing not only on how to prevent neurodegeneration but also on how to reverse it through functional and integrative therapies, giving major importance to immuno-nutrition.

Immuno-Nutrition: The Link Between Food, Immunity, and the Brain

Immuno-nutrition recognizes that food not only impacts digestion and body weight but also has a direct relationship with the immune and nervous systems.

Thousands of studies support the importance of nutrition in health, and new discoveries continue to highlight how food can activate or deactivate regenerative pathways in virtually any cell in the body.

That’s why we constantly study and research foundational topics such as:

• The intestine
• The brain
• The microbiota

And, most importantly, the relationship between them.

In a previous article, we explained that science now recognizes the existence of “three brains” in our body and the interactions among them:

1. The central nervous system brain.
2. The enteric nervous system brain — the neural network in the gut.
3. The microbiota brain — the microorganisms that send signals influencing both the first and second brains.

The Gut–Brain Connection and Permeability

Because the gut and brain are deeply interconnected, damage in one can lead to dysfunction in the other — such as in the case of intestinal permeability (leaky gut).

Permeability occurs when gaps open between the cells that form the body’s internal barriers.
For example, in leaky gut syndrome, structural changes in the intestinal wall allow the passage of food antigens, toxins, metabolic waste, and bacteria into the bloodstream.

Once in circulation, these toxic substances increase systemic inflammation and trigger an immune attack, sometimes causing the immune system to mistakenly attack the body’s own tissues, leading to autoimmune symptoms.

Remember: more than 70% of your immune system is located in your gut!
That’s why we say the gut is the gateway to all diseases.

Leaky Gut and Its Associated Conditions

Leaky gut is often associated not only with intestinal diseases like Crohn’s disease and celiac disease, but also with:

• Autism Spectrum Disorder (ASD)
• Endocrine disorders such as infertility, hypothyroidism, and endometriosis
• Food sensitivities and allergies
• Asthma and dermatitis
• And many others

Through the gut–brain axis, intestinal permeability can also reach and affect the blood–brain barrier (BBB) — the brain’s protective shield.

Just as the intestine is protected by its lining, the brain is protected by the blood–brain barrier, a network of tightly joined endothelial cells that control which molecules pass from the blood into nervous tissue.
These junctions adapt based on the brain’s metabolic needs but can weaken under chronic inflammation.

When the Gut Is Leaky, Can the Brain Be Leaky Too?

More and more scientists are saying yes.

Recent studies reveal a strong link between Leaky Gut Syndrome and neurodegenerative diseases such as Alzheimer’s, due to damage in the blood–brain barrier (Leaky BBB).

Researchers have identified immunotoxicity — triggered by gut permeability — as a major factor behind this damage.
This immunotoxicity arises from environmental toxins, dysbiotic microbiota, and food antigens (from allergens or sensitivities).

When the barrier is damaged, the immune system becomes overactivated, causing further inflammation and reduced ability to clear brain waste.
This leads to an increase in pro-inflammatory cytokines, toxin accumulation, and disruption of neural communication (synapses) — ultimately causing neuronal dysfunction and degeneration (Iadecola, 2015).

A Functional Approach to Protecting the Brain

One of the main strategies for preventing neurodegenerative and chronic diseases is to address intestinal permeability first.

Individuals may have varying degrees of gut permeability, leading to a wide range of health problems — all heavily influenced by the foods we choose to eat.

Taking care of your gut is, quite literally, taking care of your brain.

References:

Obrenovich MEM. Leaky Gut, Leaky Brain? Microorganisms. 2018 Oct 18;6(4):107. doi: 10.3390/microorganisms6040107. PMID: 30340384; PMCID: PMC6313445.

Mou Y, Du Y, Zhou L, Yue J, Hu X, Liu Y, Chen S, Lin X, Zhang G, Xiao H, Dong B. Gut Microbiota Interact With the Brain Through Systemic Chronic Inflammation: Implications on Neuroinflammation, Neurodegeneration, and Aging. Front Immunol. 2022 Apr 7;13:796288. doi: 10.3389/fimmu.2022.796288. PMID: 35464431; PMCID: PMC9021448.