Microbiome: the Gut/ Brain Connection

Having just presented this morning on the microbiome and mental health at the Integrative Medicine for Mental Health conference, I thought I’d write about the gut/ brain connection here, and I’ll try to break it down in a way that (hopefully) makes sense to everyone.

The microbiome refers to the conglomeration of microbes, mostly bacterial, that reside on and in our bodies, along with but separate from our own cells. In fact, the microbiome is made up of approximately 100 trillion bacteria, compared to 10 trillion of our own cells. We’re well outnumbered by bugs!! Our microbiome also has a major impact on every aspect of our health, including our mental health.

Every bacteria housed in our body contains a substance called LPS (lipopolysacharides). LPS exists within the structure of bacteria, and if contained in the gut does not cause problems. However, if LPS escapes into our blood stream it acts as an endotoxin, and causes a huge inflammatory response. LPS and the subsequent inflammation it causes have been implicated in everything from major depressive disorder, thyroid disorders, autism and auto-immune disease to chronic fatigue syndrome and fibromyalgia.

The bottom line is this. LPS will be released from bacteria as they die. The way the LPS and other endotoxins get into the bloodstream is through a leaky gut. That is where the cells of the small intestine open up and allow food and other molecules to flow through.

What causes leaky gut? Gluten is a major cause, and intestinal pathogens are another major cause (pathogenic bacteria, yeast and parasites). They are probably the two main triggers of leaky gut. Other food sensitivities will also contribute through their role in inflammation of the gut lining.

Once LPS is in the blood stream, it fuels inflammation. With inflammation comes the release of chemicals such as cytokines. Cytokines can cross the blood-brain barrier into the brain and cause a host of problems, leading to imbalances in neurotransmitters, overactivity of nerve cells, and damage to neurological tissue. What that could mean for us is anxiety, depression, autism, cognitive deficits, and even more severe psychiatric disorders such as bipolar and schizophrenia.

And increasingly, research is showing that it all starts in the gut.

By avoiding gluten we are minimizing the likelihood of leaky gut. Also by minimizing sugars and eating fewer processed foods, by eating lots of fiber and taking healthy probiotics, we are reducing the likelihood of the “good flora” i.e. our microbiome, getting out of balance, and “bad flora” such as pathogenic bacteria and yeast, from taking over.

So in summary –

• it is normal for us to house trillions of bacteria in our gut.
• it is normal for those bacteria to contain the substance called LPS.
• it is normal for the LPS to be released, but should be contained within the intestines and excreted out of the body.
  
  But –
  
  
• it is not normal for the LPS to escape into the bloodstream, at that point they become toxic for us and cause inflammation.
• it is not normal for the junctions between the cells of our intestinal wall to be so far apart that larger food molecules as well as LPS can escape through and cause inflammation and immune reactions.
• it is largely due to gluten, food allergens and intestinal yeast and parasites that those cells open up and the gut becomes “leaky” in the first place.

So what are the solutions?

• Eating a gluten-free diet.
• Eating fermented foods to support healthy gut flora such a kefir and kimchee.
• Taking probiotics to supplement the “good” bugs.
• Avoiding sugar and too many carbs which feed yeast.
• Getting yeast and parasites evaluated through testing, and addressing any imbalances or pathogens found.
• Healing leaky gut through taking supplements such as L-glutamine, D3, slippery elm, licorice and marshmallow.

Imbalances in our microbiome have been associated with many chronic inflammatory diseases, and have a close correlation with our mental health. It is important to take care of your gut bugs so that they take care of you!!