An Overview of the Gut-Brain Link

“All disease begins in the gut,”

At least, that’s what Hippocrates said over 2000 years ago (Hippokrátēs ho Kṓos: c. 460–c. 370 BCE).

It might seem funny to consider how your gut can influence your brain…but think about it—have you ever experienced a “gut feeling”? Chances are, that feeling in your gut was related to a specific train of thought or experience…

Here, you’ll get an idea of how the microbial life in your gut can influence your thoughts and actions, and what you can do to improve your gut health so you can thrive day after day.

What is the Gut-Brain Axis?

Simply put, the gut-brain axis is the interaction between microbes (i.e., bacteria) in your gut and the network of nerves that lead to your brain¹.

Plenty of research has shown that the gut and brain communicate through a variety of conduits, or pathways, including the autonomic nervous system, the neuroendocrine system, the enteric nervous system, and the immune system.

Molecules are passed through these networks and pathways so that changes in your gut can signal changes in your brain and vice versa. Interestingly, the changes in your gut can influence mood and cognition, to the extent that it may play a role in various forms of psychiatric illness².

An interesting component of the gut-brain axis is what is known as the gut microbiome, which is just a fancy phrase for “all things living in your gut”.

The microbiome is at the forefront of gut-brain axis research because scientists have discovered that changes to the microbiome, such as having different strains of bacteria in your gut (i.e., gastrointestinal tract), can negatively affect your thoughts and feelings³.

What Does the Science Say?

Cutting-edge research is showing that simply changing the type of bacteria in the gut can actually improve symptoms of depression and anxiety⁴.

In fact, scientists have found that removing fecal matter from healthy individuals and placing it in the gut of a depressed or anxious person dramatically increased their mood and reduced feelings of worry⁵.

Interestingly, in the same study, researchers took the fecal matter from the depressed patients and transplanted it in the gut of healthy individuals, and they became depressed shortly after!

This was one of the first studies to demonstrate that taking bacteria from a healthy person and placing that bacteria into a depressed person (or vice versa) had a direct effect on mood.

In addition, science is beginning to show that the gut-brain axis is an important element to consider when dealing with chronic diseases like irritable bowel syndrome⁶, Alzheimer’s disease⁷, Parkinson’s disease⁸, and even migraine headaches⁹!

Importantly, researchers have found that one of the primary ways the gut can communicate with the brain and contribute to changes in mental health is through inflammation¹⁰.

How Can I Improve My Microbiome?

There are many ways you can improve your microbiome, and one of the most direct ways is through supplements.

Probiotic supplements can be the best way to directly change your microbiome, but the key to taking probiotics is making sure you pick the right ones¹¹. Notably, researchers have developed a thorough guide so you can understand what different strains of probiotics can do—and more importantly, not do—for you¹²_.

Another interesting approach is to feed the bacteria that live in your gut with prebiotics, which are components found in things like dandelion, artichoke, garlic, onions, asparagus, bananas, and apples¹³.

Finally, there is evidence that exercise can be a very good way to improve your microbiome.

In fact, exercise may even change the bacteria that lives in your gut to favor the kind that promote a healthier and happier life¹⁴_, which may play a role in the stress-buffering effects of exercise^15,16. 

Conclusion

Now, you should have an idea as to how your gut can influence your brain, and the approaches you can take to improve your gut microbiome.

Doing so will not only make you feel better, but it may even give you an edge in your next sports performance¹⁷ and may even improve your ability to think and focus¹⁸.

As always, consult your physician before making any significant changes to your diet and/or lifestyle.

Author: Brett Melanson is a PhD Candidate in Behavioral Neuroscience. His interests primarily reside within the life sciences with an emphasis on stress-based psychopathologies.