The Gut-Brain Axis and How It Influences Emotion and the Feeling Response

In our previous blog, we discussed the vitally important topic of the gut-brain axis or GBA and how the relationship between the two is a highly symbiotic one. We discussed how understanding and supporting the communicative link between belly and brain is an important first step in ensuring physical balance and vitality and how it may even help reverse many chronic conditions. In this article, we’ll go a step beyond and explore how the belly—our other brain—is the seat of our felt emotion.


Internationally recognized educator and thought leader on the microbiome(1) as it relates to health, disease, and food systems, Zach Bush, MD says:


“The microbiome has now come to be seen as the foundation of human life, health, and most interesting to me – human consciousness itself. Grandiose and ridiculous to the medical mindset, it is thoroughly obvious to the naturalist. We cannot exist apart from the biology of the microbiome, so how could we possibly rise to a high level of awareness without the connection to this rudimentary source of intelligence. As we become aware of the invisible life within and around us, we can seize new opportunity to move our species toward a healthier future.”

It’s this “rudimentary source of intelligence” that has led us all into moments when, in a certain situation, we simply felt something wasn’t right. We didn’t feel it in our heads. We felt it in our bellies.


We might even have felt it as quite a physical sensation or maybe it was a more subtle feeling. These are examples that demonstrate to us how the gut often reacts faster than the mind or brain.


On the other hand, many of us have experienced this phenomenon in reverse, where we intellectually know something to be so, and it turns our stomach in knots. Or we’re nervous to meet someone and we feel ‘butterflies’ in our stomachs.


Both of these scenarios perfectly illustrate the constant back-and-forth dialogue between mind/brain, nervous system and gut. (Read our blog on this subject here.) At the risk of oversimplifying, here’s why we feel emotion in our bellies, why we get gut feelings and how our mood or emotionality is influenced by our intestinal terrain populated by bacteria.


It’s important to understand that the nervous system is composed of two main parts:


1. the central nervous system: brain and spinal cord;

2. the peripheral nervous system: nerves that branch off from the spinal cord extending to all parts of the body including the more than 100 million nerve cells in the gut, the same nerve cells that are in the brain.


The brain and gut are connected by a bundle of nerve fibers called the vagus nerve. It is now known that the brain, the gut and the trillions of microorganisms that thrive in the gut, all communicate with each other, their signals transported back and forth along the vagus nerve.

So when the brain, which is very much like a computer, processes information with lightning speed and then transmits that information to the gut via the vagus nerve, the gut responds with communication in turn and also often interprets a physical response in the belly.


Numerous studies show that gut bacteria is related to mental, even emotional health.


Scientists have found that beneficial gut bacteria produce neurotransmitters such as dopamine, norepinephrine, acetylcholine, and GABA all of which are critical for balanced mood and emotion, concentration, reward, and motivation. The gut microbiome actually causes changes in how our brains react.


For example, the messenger that travels between the gut and brain is serotonin, the ‘happy’ hormone. A ‘happy,’ healthy gut communicates well-being to the brain. Friendly flora in the intestines manufacture about 95 percent of the body's supply of serotonin, which not only influences gastrointestinal activity, it influences mood, thus emotion.


The following example illustrates the gut-brain axis relationship and how mental and emotional health is affected.


In a UCLA study, and prior to the experiment, researchers first collected brain images of a group of healthy women free of gastrointestinal or psychiatric issues and then randomly assigned each woman to one of three distinct groups consuming either:


• a fermented milk product—a probiotic-rich yogurt;

• a non-fermented milk product containing five strains of probiotics added in (friendly flora or bacteria); or

• no intervention whatsoever in the milk product.


They consumed their assigned products twice a day for four weeks.


At the end of four weeks, the women were given an ‘emotional faces attention task.’ In this task, the women were shown images of emotional faces requiring not just their attention but obviously, neural processing.


The results were astonishing.


New brain images gathered during the emotional task showed remarkable differences in how the three ‘brain groups’ reacted during the emotional task.


The women who consumed the fermented milk product and milk with probiotics added showed calmer brains.


The no-intervention group showed the opposite with significantly more brain hyperactivity during the emotional task.


This study concludes that exposure and consumption of good bacteria are necessary for a balanced mental and emotional function and well-being.


Kelly Burris, Ph. D, in Depression Anxiety and the Brain in Your Gut: How Thought, Emotion and Behavior Work and How to Get Back to Normal tell us this:

“With over 500 million neurons (brain cells) in the gut and bidirectional communication with the brain via the vagus nerve, gut health must not only be considered in emotional wellness (mental health) but must also be measured.”

Researchers also find that stress and our inability to adapt to it not only makes us more likely to develop emotional imbalance, it makes the gut more permeable to bacteria.


Depression causes an imbalance of good to bad gut bacteria. Depression can be potentially caused by a dysfunctional gut-brain axis.


Your second brain, your gut, is not just a physical mechanism helping you to digest food, absorb nutrients and eliminate waste. It wields power over your emotional and mental health.


It obviously isn't capable of reason. It simply and dutifully communicates back to the brain in response to what is presented to it.


It may trigger a serious emotional shift should you experience irritation in your gastrointestinal system such as irritable bowel syndrome, for example.


Unfortunately, most people take their guts' health for granted.


Enhance your gut health for life and elevate your physical and emotional well-being. Keep your second brain fit and healthy by:


• becoming informed about the best foods to eat and avoid;

• discovering the best prebiotics, probiotics, and psychobiotics(2) to consume; and

• learning to optimize your exercise routines.


A healthy gut-brain axis is known to successfully regulate inflammation successfully. It will reduce your risk for chronic illnesses and give you more beautiful glowing skin.


And just as wonderfully, a healthy gut-brain axis will create for you a remarkable boost in mental clarity, energy, and motivation and a heightened emotional feeling of well-being.

(1) Microbiome: the combined genetic material of the microorganisms in a particular environment

(2) Psychobiotics: a term used in preliminary research to refer to live bacteria that, when ingested in appropriate amounts, might confer a mental health benefit by affecting microbiota of the host organi

Gut Brain Axis/Biome Treatment

Tucker, Tammy. The Belly Brain Solution: Gut-Brain Axis Connection to Health. N.p., CreateSpace Independent Publishing Platform, 2018


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/

Carabotti, Marilia et al. “The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems.” Annals of gastroenterology vol. 28,2 (2015): 203-209.


Burris, Ph.D., Kelly. Depression Anxiety and the Brain in Your Gut: How Thought, Emotion and Behavior Work and How to Get Back to Normal. United States, Illumine Studios, 2016.


Tillisch, Kirsten et al. “Consumption of fermented milk product with probiotic modulates brain activity.” Gastroenterology vol. 144,7 (2013): 1394-401, 1401.e1-4. doi:10.1053/j.gastro.2013.02.043


Dennis, Tracy A, and Chao-Cheng Chen. “Emotional face processing and attention performance in three domains: neurophysiological mechanisms and moderating effects of trait anxiety.” International journal of psychophysiology : official journal of the International Organization of Psychophysiology vol. 65,1 (2007): 10-9. doi:10.1016/j.ijpsycho.2007.02.006


“Gut Bacteria Can Influence Your Mood, Thoughts, and Brain.” Psychology Today, Sussex Publishers, https://www.psychologytoday.com/us/blog/neuroscience-in-everyday-life/201908/gut-bacteria-can-influence-your-mood-thoughts-brain.


Mayer, Emeran. The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health. Germany, Harper Wave, 2018.


Carter, Leo. Your Second Brain: And Why Its The Key To Your Health, Success And Happiness. N.p., Independently Published, 2020.


https://www.nichd.nih.gov/health/topics/neuro/conditioninfo/parts