Better Gut Health Leads to Better Brain

by | Brain Health, Focus

It seems gut health talk is everywhere these days, but it might be hard to make sense of it all.

Luckily, we made this ultimate guide to gut health to explain the ins and outs about what goes on in the wild world of your gut and why it’s vital to keeping your memory sharp and improving focus and brainpower.

First off — Why does your gut even matter?

Well, it isn’t called the Second Brain for nothing. Perhaps some quick stats will give you an idea:

Your gut bacteria can weigh up to 2 kilograms and include 1000 different known types of bacteria, so those tiny bacteria are rather significant(1).

⅔  of your gut is unique to you, and there your gut bacteria have over 3 million genes — 150x more than the human genome(1).

About 80% of your immune system cells live in your gut, and lack of healthy bacteria can also leave you more susceptible to inflammatory health conditions and autoimmune diseases (2). So when cold season comes around, know that it’s your gut that can determine how and if you stay healthy.

At least 70 million people in the U.S. suffer from some form of digestive illness (not including heartburn), and in 2013  digestive diseases accounted for 114 billion dollars of medical expenses(3).

So keeping your gut healthy is probably in your economic interest, as well as your brain’s. After all, they say health is wealth.

However, your gut does a WHOLE lot more than digest your food and support the immune system — its health is critical to absorbing nutrients properly, keeping your blood sugar in check, managing inflammation, fighting bad bacteria,  managing hormones, making your brain running smoothly, and keeping you in a good mood.

Wait — My Gut can Affect My Brain? Can I Use it to Boost my Brain?

In a sense, yes! Your gut and brain are always communicating through something called the Enteric Nervous System, and your gut bacteria regulate that communication. (4)

Additionally, your gut uses around 30 different kinds of neurotransmitters, as well as producing norepinephrine, acetylcholine, dopamine, GABA, and 95% of your serotonin(5,6,7)!

On top of that, your gut bacteria convert the complex carbs you eat into fatty acids that can cross the blood-brain barrier and affect your levels of BDNF (brain-derived neurotrophic factor — a fancy term for a chemical that essentially creates and protects the existence of neurons and the brain’s learning and memory capabilities).

Moreover, your gut bacteria have been shown to manage your neuroplasticity (how well your brain adapts and learns, etc.) and neurogenesis (creation of new neurons)(8).

Furthermore, your gut supremely affects your mood and mental health. One study published in the Journal of Psychiatric Research found that patients with bipolar disorder had severely poor gut health(9).

Furthermore, weakened gut health and inflammation can cause brain fog, and is a primary factor in depression, anxiety, ADHD, and inflammatory brain conditions such as Alzheimer’s disease and dementia (10,11).

Okay, so you’ve got my attention — how do I make sure none of those unpleasant symptoms happen to me —  a.k.a. how do I help my gut?

Get Moving!

Microbiomes are healthier and more diverse in those who are physically active, and studies show that exercise can help improve your gut health(12).


Messing with your natural circadian rhythms and not getting enough sleep can negatively impact your gut, leading to a depleted microbiome. (13,14) Try to go to bed and wake up at regular times, or at least get enough sleep (8 hours or more).


Reduce Stress

Your gut manages your cortisol levels, but too much stress can harm the gut; the two are inextricably linked.

High levels of stress damage intestinal microbiota and increase intestinal permeability(a factor in leaky gut syndrome) and the likelihood of developing Inflammatory Bowel Syndrome  (15, 16).


Avoid antibiotics unless necessary

Antibiotics can be lifesaving. However, they kill all bacteria, including the good ones, so don’t take them unless you absolutely have to. Moreover, avoid meat, fish and dairy products that may contain antibiotics.

Avoid Processed foods and Sugar!

Refined sugar feeds the detrimental bacteria. Processed foods also cause inflammation which hurts the gut. See our list of brain busters if you want to know what consists of processed foods.

“The best way to restore your gut is to stop assaulting it [with processed food] all the time,” said Patricia Raymond, MD, in an article in Experience Life Magazine(17).

See if you have food intolerances

Many of us don’t know we have intolerances. People are often sensitive to wheat, gluten, dairy, corn, and soy.

In 2005 some 30-50 million Americans were lactose intolerant, and often people don’t realize they’re sensitive(18). Food intolerance is harder to track, but 2011 estimates had its prevalence range from 2% to 20%.

 90% of all allergies and sensitivities were related to milk, eggs, peanuts, tree nuts, fish, shellfish, wheat, or soy(19). Gluten has been suggested as a cause of leaky gut syndrome (20) since it can sometimes make you produce too much of a protein called zonulin which opens up the tight junctions between cells in your digestive tract (aka causing leaky gut which causes inflammation (21).

Thus, it’s a good idea to test and see if you’re intolerant or sensitive to some of these foods; they could but impacting your gut without your knowledge.

If you’re not sensitive, great! If you do find yourself with a sensitivity or intolerance, it’s a good idea to avoid those foods for your gut’s sake.

Eat Pro and Prebiotics

This craze has merit. Essentially: Prebiotics feed the good guys, probiotics give you more of the good guys.

Wait, but aren’t pro and prebiotics just something people say their product has to jack up the price?

Yes and no. Some foods and brands say they are probiotic to get more $$,  but don’t dismiss probiotics.

Remember how gut imbalances can impact mental health?

One study discovered that 2x as many patients felt depressive symptoms improve after they took a probiotic vs. those who received a placebo. Researchers thus linked gut improvement to improvement of mental wellbeing. (24)  

Another study found that consuming probiotics lowered negative thoughts associated with a sad mood (25).

On top of that, your gut health may be crucial for weight regulation. A study at Washington University in St. Louis found that weight can be strongly correlated to gut bacteria and the makeup of a microbiome.

They found that the microbiomes of obese mice had a much more of one bacteria (Firmicutes) vs. another (bacteroidetes) and thin mice were the opposite. So they took germ-free mice and gave one group bacteria from the obese mice and another bacteria from the thin mice.

Fed the same diet, the group infected with bacteria from the obese mice saw a 47% increase in body fat vs. a 27% increase in body fat in the group given bacteria from the thin mice(26,27).

So you’re saying my gut health can make me lose or gain weight?

Research shows it’s highly likely. Yang-Xin Fu, MD, Ph.D., professor of pathology at the University of Chicago, and his team studied this microbiome-obesity connection, publishing a study in the Nature Immunology journal in 2012.

They found that certain microbes are required to absorb energy (think calories) from food, and this process determines weight gain. Essentially, they determined that the bacteria associated with obesity didn’t need much food or energy to reproduce, so there were more leftover calories for the host to absorb.

Microbes that kept mice and humans thin “ate” more calories.(28,26). Given that probiotics help give you more good bacteria, you can see why they’re beneficial for weight management.

But the benefits of probiotics don’t stop there. A study published in the Frontiers in Aging Neuroscience researched the effect of probiotics on a group of 60 Alzheimer’s patients. Half the group got a placebo the other half had drunk probiotic milk.

At the end of the study, they found that inflammation markers in the group taking a probiotic had lowered by 18%, but inflammation markers in the placebo group went up by 45%. Moreover, the group on probiotics even increased their brain function.

Lead researcher Rudolph Tanzi, Ph.D., said “If you take care of your microbiome, it’ll take care of you — and that’s all the way up to your brain,” says leading Alzheimer’s researcher Rudolph Tanzi, PhD. (29,30, 31)

In fact, research shows that your microbiome is essential for healthy brain development when younger, as well as keeping it functioning well in adulthood, such as managing neuroplasticity and neurogenesis(32).

Giving your gut probiotic foods like yogurt (most non-dairy yogurts have added probiotics), kefir, sauerkraut, kimchi, non-pasteurized pickled foods, or even taking a supplement is vital for keeping your brain sharp.

However, you need to be sure to consume prebiotic fiber as well. Prebiotics feed the good bacteria, so try to eat more foods high in resistant starch and prebiotic fiber, such as legumes (chickpeas, white beans, lentils), green banana, Jerusalem artichoke, asparagus, onions, garlic, chicory root, dandelion greens, jicama, and leeks.

In Conclusion

  • Gut health is not a fad but something crucial to your health and brain functioning.
  • Poor gut health can cause brain fog, worsened mental health, weight gain, digestive issues, and much much more.
  • To improve gut health — eat pre and probiotic foods, exercise, sleep well, manage stress, avoid antibiotics unless necessary, cut out processed foods, and check if you have food intolerances.