Relationship between the gut and the brain

Relationship between the gut and the brain

This is part two of a three part series exploring the relationships between the fasting, the gut and the brain as well as the herbs that can help when fasting. You can read Part 1 here.

There's a fascinating relationship between fasting and the gut microbiome. When fasting, the body undergoes autophagy, also known as cellular cleansing. Periodic fasting can alter the composition and metabolic activity of our gut microbiome as it gives our microbes a rest and allows for a much more efficient cleansing of the gut. When the body isn't busy digesting food, it has energy to focus on healing itself. Our body wants to heal but most importantly it has the ability to do so! Fasting helps accelerate and boost the natural process of autophagy, supporting the body in getting rid of damaged cells and making space for new, healthy ones.

The most obvious benefits of fasting are weight loss and type 2 diabetes improvement, but another key benefit is neurological: fasting can benefit the brain!



The connection between the gut and brain begins in the embryo. Did you know that both organs originate from the same group of cells (neural crest cells)? It's only during foetal development in your mother’s womb that these cells migrate to different parts of your body, thus giving rise to the gut and brain.

The connection between these two organs is further amplified by the vagus nerve, which is the longest of the 12 cranial nerves. Cranial nerves are pairs of nerves that connect your brain to different parts of the body, and the vagus nerve transmits both sensory (i.e smell & sight) and motor (i.e muscle movements) information to organs in the body. The vagus nerve is thus considered as the major information highway connecting the gut and brain.


Happiness is found in your gut!

Anti-depressant drugs target serotonin receptors (the happiness hormone) in the brain, so it’s a common and logical assumption that most of the happy hormone is found in the brain. But this is FALSE. There has been a revolutionary breakthrough showing that over 90% of serotonin is actually found in the gut! (1)

Have you ever had junk food and felt tired, lethargic and in a low mood? Have you ever eaten a light, colourful, plant-based meal that has made you feel vitalized and energetic?

If so, you can relate to the statement that what you eat is extremely important to ward off anxiety and depression. However, studies are also plentiful in showing that giving your gut a rest is also beneficial for mood regulation. Indeed, it’s been shown that serotonin and its precursor tryptophan have increased availability when fasting. Another mechanism behind mood improvement during fasting could be the release of endogenous endorphins. It’s been reported that there is an increase of endogenous opiate production during the first 24 hours of fasting. Mood improvement that occurs during the first few days of fasting could thus be a direct consequence of the release of these neurotransmitters and endorphins.

You are what you eat, and what you don't eat 

How you think and what you think affects your gut, and conversely what and when you eat affects how you think. Giving your body a break from digestion can in turn relieve mental fog and enhance mental clarity. Since the two organs are communicating so closely, make sure they’re doing so to benefit (and not hinder) your mental and physical health!

In the next post we will share 5 of our favourite herbs that help accelerate the benefits of fasting. Read part 3


This is part two of a three part series exploring the relationships between the fasting, the gut and the brain as well as the herbs that can help when fasting. You can read Part 1 here.

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