Gut-Brain Axis: The Connection Between Brain Health and Your Gut

How to Tell if Your Gut Health is Optimal

Usually when want to improve our brain function for whatever reason, we think we need a substance that acts directly on the brain – like caffeine, a pill or a stimulant. However, what holds a vital and irreplaceable key to optimal brain health is not some special kind of neurotransmitter, expensive supplement or pill, but rather: a healthy digestive system.

We don’t usually think of the brain and gut being related. In the west, we have a tendency to view things as specialized organs. More and more research is coming out about the GUT BRAIN axis, and how what we eat and the state of our digestive systems actually determines not just our cognitive function, but our risk for disease and our overall health.

Only very recently have we started learning about the microbiome, which is the diverse colony of bacteria that live in our bodies and digestive system. You’ve heard of them as “Probiotics.” These microbes outnumber our human cells by 10 to ONE! 100 TRILLION invisible creatures who do everything from digest our food, regulate our immune system, detoxification, controlling inflammation, nutrient absorption, weight management – all of these factor into whether we experience allergies, asthma, mood disorders, autism and ADHD, cancer, autoimmune disease, diabetes and, especially, dementia.

Read more about the microbiome

Enormous advances in recent research are showing that beneficial gut bacteria support not only a healthy immune system (as 80% of our immune system resides in our gut), but positive mood and emotional well-being. 90% of the “happy hormone” serotonin is produced in the digestive system! The gut is truly our second brain. Collected together, the bacteria in your gut would weight about three to four pounds – the same weight as your brain! Our digestive system affects the way we feel; it dictates our mood, our sleep, our reaction to stress. It literally communicates with the brain via an advanced neuro-feedback loop called the “Gut-Brain Axis.”

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And we have a huge problem. The modern world and the Standard American Diet (SAD) are not conducive to gut health.

Antibiotics, NSAIDs like tylenol, prescription medications, birth control, pesticides and herbicides, environmental toxins, heavy metals, parasite infections and especially a diet full of refined foods and gluten with high sugar and low fiber diets all starve and severely damage the our good bugs. Without a healthy microbiome, we are exponentially more susceptible to inflammation, disease, depression and dementia.

The takeaway: You must have a healthy gut to have a healthy brain. And the most exciting part is: you can positively change your microbiome and in doing so, boost your cognitive function, ability to manage stress, and overall happiness. It’s all about prevention! What you eat matters.

Read: What Stress Does to Your Hormones + 3 Proven Stress Management Strategies

3 Steps To Incorporate Now:

1. Limit your carbohydrate and gluten intake.

They are inflammatory substances that can increase one’s risk of disease. Many people believe that going “gluten free” is a fad diet, but sadly the science supports that it is not. As much as it is a downer to hear because we ALL love them, refined and excess carbohydrates and gluten are some of the most damaging foods that we can eat; not just for your brain but for your digestive system and overall health.

Here’s why: Carbohydrates turn into sugar when they are digested; and sugar raises your blood glucose levels. The research indicates that even slight elevations of blood sugar far below the diabetes range have been shown to significantly increase the risk of untreatable dementia, and some neurologists are now referring to Alzheimer's as “Type 3 Diabetes.”

One of the reasons for this is gluten. Our digestive system is a barrier from the outside world. It has its own immune system, called the GALT: Gut Associated Lymphatic Tissue. That lining is very fragile – only one cell wall lining thick. When it gets damaged, it can’t keep the bad guys out of your bloodstream, and your immune system has to constantly react to defend you. This process is inflammation at work, but on a microscopic level. Gluten also triggers the release of “zonulin,” a hormone that tells these tight cell junctures to OPEN – allowing large particles to pass into your bloodstream that your immune system attacks. Zonulin also tells the Blood Brain barrier to open, thus creating inflammation in the brain.

Yes, it is true that some people tolerate gluten more than others. But this zonulin effect does not just happen to celiacs – it is happening to everyone who consumes it! Inflammation is the door to disease. The more we can eliminate it from our diets and our lives, the higher likelihood we can prevent disease, especially neurodegenerative ones as we age.

2. Consume ample fermented foods & probiotics.

We are far more bacteria than we are human. Rebuilding our “good” digestive bacteria is the best way to strengthen the immune system and mentally perform at the highest level. Probiotic foods and supplements are important as they replace missing or insufficient healthy bacterial species, restoring balance. Fermented foods are living sources of probiotic beneficial bacteria.

Kefir, sauerkraut, kimchee, dairy and non-dairy yogurt, kombucha, apple cider vinegar and real pickles are all excellent sources of naturally probiotic-rich foods. Research has shown that people who consume fermented foods have not only far better immune function, but also elevated moods and the increased ability to tolerate stress than those who do not.

Read more about probiotics as the key to a healthy, happy gut

Adding in supplemental probiotics can also help, look for the refrigerated strains in a local health food store: the more billion, the better. You should especially take probiotic supplements after a round of antibiotics, as antibiotics kill off both the good and the bad bacteria in your body.

3. Don’t be afraid of HEALTHY fats!

Our brains are made primarily of fat, and fat, not sugar, is the brain’s preferred source of fuel! Fat Phobia is all wrong: it’s about quality vs. quantity. Fats we were told are “healthy,” like canola oil, are actually extremely inflammatory to the body. A low-fat diet has been proven to be extremely dangerous for brain health in the long run, resulting in increased prevalence of neurodegenerative disorders.

It is for this reason that we do not need to continue avoiding healthful foods like grass-fed butter and nutritious egg-yolks. Olive oil, coconut oil, ghee, fatty fish like salmon and sardines, olives, avocados, coconut, nuts and nut butters, seeds and cheese if you tolerate are all important sources of healthy fats.

It’s worth nothing that fats will only make you gain weight if you are eating them alongside excessive carbs. My message is: don’t fear the fat! Your body and your brain will thank you.

Written by Kacie Carter. This article originally appeared on

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Maria is a journalist, activist, sister, daughter, wife, and mother. She is the ex-wife of Arnold Schwarzenegger. She served as the first lady of California. She was a writer, producer, and anchor at both CBS News and NBC News. She built the largest women's conference. to empower women from all walks of life. She started the Minerva Awards to honor women who were making a difference on the frontlines of humanity. Her mission is to challenge what is, imagine what can be, make a difference and move humanity forward in all areas of human endeavor.