Gut Matters: Unveiling the Powerhouse Within - A Four Part Blog Series
A Four-Part Blog Series
By Carrie Colarusso, Holistic Nutrition Therapist
I'm sure you've all heard the buzz about gut health, microbiome, probiotics, and more. But what exactly is "the gut," and why does it matter for your overall wellness?
In this 4-part blog series, I’ll break down how your gut interacts with other parts of your body, why it's crucial to your health, and how to make sense of all the information out there.
Join me on this journey to a clearer understanding and ways to improve your health.
My name is Carrie Colarusso and I am the founder of Wholistic Health & Wellness. As a Holistic Nutrition Therapist and healthcare professional, my mission is to educate individuals on the significance of nutrition and self-care in improving both physical and mental well-being. My goal is to empower you to manage your health, enhance your quality of life, and optimize wellness. One area I address is gut health. This blog series is meant to provide you with insight on how the gut affects the body and mind.
Table of Contents
Part 1: The Gut-Brain Connection
Why the gut is considered the “second brain” and how it affects our mood
Microbiome
Part 2: The Gut and The Immune System
How the microorganisms in the gut (known as the microbiota) effects our immune system
Absorption and production of nutrients
Part 3: The Gut and Detoxification
How the gut plays a role in the detoxification processes inside our body.
Effects on the liver
Part 4: Nurturing Your Gut
A healthy gut leads to better mood, robust immunity and efficient detoxification.
Key Terms
Enteric Nervous System: The nervous system that lives within the walls of the GI tract.
Central Nervous System: The system of nerves that live within the brain and spinal cord and control the body.
Vagus Nerve: The longest nerve which runs from the CNS in the brain stem, through the chest, abdomen and to the ENS of the gut. It is the communicator of the gut-brain connection and is the major part of what is referred to as the gut-brain axis.
The gut-brain axis: The nervous systems, Vagus nerve, neurotransmitters and hormones, and the microbiome of the gut collectively.
Microbiota: The environment or community of microorganisms within the gut. It includes bacteria, fungi, parasites and viruses.
Microbiome: The microbiome refers to the combined genetic material of all the microorganisms in the gut.
Probiotics: Live microorganisms introduced to the microbiome for beneficial effects.
Prebiotics: Fibrous, starchy foods that live microorganisms feed off.
Dysbiosis: A loss of beneficial bacteria, or more bad than good, which leaves your gut vulnerable to more detrimental or invasive types, diminishing the overall diversity in your microbiome.
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Part One: The Gut-Brain Connection
Why the gut is considered our “second brain” and how it affects our mood
I am sure you have all heard the term “go with your gut” or “gut intuition” or have had “a gut feeling” sometime in your life. Well did you know where this term comes from? Read on to learn why our gut is referred to as our “second brain.”
What is the “Gut?
The gut is the gastrointestinal tract (GI tract), or digestive system, which includes the esophagus, stomach, and small and large intestines. The large intestine is also referred to as the colon, which is the major part of the large intestine. For the purpose of this blog series the “gut” refers to the large intestines.
The health of our gut is critical to overall human health, aiding in the digestion and absorption of essential nutrients, modulating the immune system, detoxifying potentially dangerous compounds and even aiding in mood balance.
The gut harbors a large community of microbes (bacteria, parasites, fungi, and viruses) that are crucial to overall health.
The gut also contains a mucus membrane inner lining that contains nerves that interact with the rest of our body.
Both of these components have a role in the gut-brain connection and the reason behind being deemed “the second brain.
The Enteric Nervous System (ENS)
The brain and the rest of the body communicate through electrical signals through nerves, known as the nervous system. All body control is managed through the nervous system.
The brain and spinal cord contain the central nervous system (CNS) which controls everything the body does, and the rest of the body contains the peripheral nervous system (PNS). The PNS is further categorized into types and subtypes. One of the subtypes is the enteric nervous system (ENS).
Hidden in the walls of the digestive system is the enteric nervous system (ENS). The ENS is two thin layers of over 500 million nerve cells lining your GI tract. It is the most complex nerve network second to the brain.
Although the main role of the ENS is controlling digestion, which it can do without involving the central nervous system for this function, it communicates profoundly with the brain.
For decades, researchers and doctors thought that anxiety and depression contributed to irritable bowel syndrome (IBS) and other bowel issues, but studies show that it may also be the other way around. Researchers are finding evidence that irritation in the GI system causes the ENS to send signals to the CNS that can trigger mood changes.
Our brains and digestive systems have evolved together for survival. What we eat is crucial to our overall health. Our brains and guts needed to stay in contact to make sure we got the nutrients we needed and a process in place to halt digestion if we ate something bad or wrong. That’s how the ENS and CNS work together.
“More information passes between your brain and your gut than any other body system. In fact, there are more nerve cells in your gut than anywhere else in your body outside of your brain.”
The Vagus Nerve
The Vagus nerve is the connection between the ENS and CNS. This nerve and these nervous systems along with other gut-brain pathways are collectively called the gut-brain axis.
The Vagus nerve is the main link between your enteric nervous system, the gut, and your central nervous system, the brain. It’s part of the peripheral nervous system and one of the longest nerves in the body.
It begins at the brainstem and tracts down through the neck, the chest and the abdomen. It interacts with all organs along the way.
This nerve acts as a bidirectional channel, enabling the rapid exchange of signals from the brain to the gut and vice versa. Your Vagus nerve relays information about the conditions inside your gut from your enteric nervous system to your brain. In response, it relays signals from your brain to your gut.
“This continuous communication allows the brain and gut to be in sync. This expansive network highlights the gut-brain axis’s complexity, integrating diverse physiological signals to maintain mind and body balance.” (Maya Shetty)
Specifically, the Vagus nerve is part of the parasympathetic nervous system, which calms your body after you've been in a stressful situation. It carries signals from your brain to other parts of your body, like your heart and gut, to initiate the calming process. This is why stressful conditions can cause gut and digestion issues because it can affect the Vagus nerve signaling.
In addition, when the gut is imbalanced or unhealthy, the Vagus nerve serves as the messenger from the ENS to the brain which initiates stress and other mood responses in the brain. That brings us to our next point; gut microbiome and mood.
The Microbiome
The gut microbiome is made up of a vast community of live microorganisms called microbiota. It is made up of live bacteria, fungi, parasites and viruses and is considered the most significant community of microbe in maintaining our health. The gut bacteria serve many roles in balancing our body and keeping us healthy.
Responsible for digestion and absorption of nutrients from food we eat as well as producing byproducts that help synthesize (make) some nutrients such as vitamins, amino acids (proteins) and lipids (fats) needed for the body.
Inhibits inflammation and promotes healthy immune function.
Produce or help produce many of the chemical neurotransmitters (chemicals which help transmit signals) for the ENS to convey messages between your gut and brain.
Produce hormones, and metabolites (by products from digestion) that can affect our emotions, thought processes, and behaviors.
The gut microbiota respond to neurotransmitters and hormones from the brain but also produce them. The microbiota produce hormones that regulate thoughts and emotions.
Hormones such as serotonin, dopamine, and GABA which are considered our “feel good” hormones and have a direct impact on mood and mood disorders.
Responsible for producing over 90% of our body’s serotonin. Serotonin is the most widely recognized hormone responsible for mood regulation in the brain.
Variations in gut bacteria can impact serotonin synthesis in the brain, which influences our mood and behavior.
“Increasing evidence is showing that bacteria in the gut, and the byproducts they produce, affect mood, cognition, and behavior.” (Dr. Spencer, Gastroenterologist and Physician Scientist at Stanford University)
Through the numerous studies, it is evident that our microbiota exerts a profound influence on the gut-brain communication. When we think about stress, mood swings, anxiety, depression or even more serious medically diagnosed mood disorders, we instantly think brain involvement. Our gut microbiota is playing a larger part of our mood and brain activity that we knew.
“The complex interplay between our microbiome and brain is a testament to the body’s remarkable interconnectedness. It’s not just about gut health or mental health; it’s about how each influences the other in profound ways.” (Dr. Spencer, Gastroenterologist and Physician Scientist at Stanford University)
It’s clear there is good reason why the gut is deemed the “second brain.” Perhaps working on a healthy and balanced gut microbiota can bring us a balanced mood.
Read on to Part Two: The Gut and Immune System
PART ONE REFERENCES
- Barron K. The Impact of Stress on Gut Health & Detox - WholisticMatters. WholisticMatters. Published November 19, 2022. Accessed August 10, 2024. https://wholisticmatters.com/stress-gut-detox/
- The Brain-Gut Connection. Hopkinsmedicine.org. Published January 24, 2024. Accessed August 10, 2024. https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-brain-gut-connection#:~:text=For%20decades%2C%20researchers%20and%20doctors
- Cleveland Clinic. Central Nervous System: What Does It Do? Cleveland Clinic. Published November 12, 2023. https://my.clevelandclinic.org/health/body/central-nervous-system-cns
- Cleveland Clinic. What To Know About the Gut-Brain Connection. Cleveland Clinic. Published September 20, 2023. https://my.clevelandclinic.org/health/body/the-gut-brain-connection
- Cleveland Clinic. What Is Your Gut Microbiome? Cleveland Clinic. Published August 18, 2023. https://my.clevelandclinic.org/health/body/25201-gut-microbiome
- Shetty M. More Than a Gut Feeling: How Your Microbiome Affects Your Mood | Cognitive Enhancement. Lifestyle Medicine. Published April 8, 2024. Accessed August 10, 2024. https://longevity.stanford.edu/lifestyle/2024/04/08/more-than-a-gut-feeling-how-your-microbiome-affects-your-mood/#:~:text=Neurotransmitters%20are%20crucial%20for%20communication
- Robertson R. Why the Gut Microbiome Is Crucial for Your Health. Healthline. Published June 27, 2017. https://www.healthline.com/nutrition/gut-microbiome-and-health#TOC_TITLE_HDR_6
- How does the nervous system work? www.ncbi.nlm.nih.gov. Published August 19, 2016. https://www.ncbi.nlm.nih.gov/books/NBK279390/#:~:text=The%20nervous%20system%20is%20made
- Segal D. Vagus Nerve: What to Know. WebMD. Published October 6, 2022. https://www.webmd.com/brain/vagus-nerve-what-to-know
- Hou K, Wu ZX, Chen XY, et al. Microbiota in Health and Diseases. Signal Transduction and Targeted Therapy. 2022;7(1). doi:https://doi.org/10.1038/s41392-022-00974-4
- Amjad Mhanna, Martini N, Ghefar Hmaydoosh, et al. The correlation between gut microbiota and both neurotransmitters and mental disorders: A narrative review. Medicine. 2024;103(5):e37114-e37114. doi:https://doi.org/10.1097/md.0000000000037114