What if we could drastically improve our health, our immune system, and even eliminate anxiety and depression simply by making small changes that affect the health of our gut? Current research is examining this idea, and there is strong evidence that the food choices we make affect the health of our digestive system.
Does the health of our digestive system really influence such a variety of seemingly unrelated problems like eczema and anxiety? Are “Gut Health”, “Leaky Gut”, Fermented Foods, and Probiotics just current fads?
I was curious, and wanted to know more, so last year I started researching these topics, examining the science behind these popular claims. What I discovered amazed me.
I want to tell you that the health of our digestive system has a powerful effect on nearly every aspect of our well-being. Yes, I was skeptical at first, but the more I looked at the past and current research, the more fascinated I became. And of course, as a dietitian, I understand that ultimately food is our medicine, and our poison.
What does “Gut Health” mean exactly?
Heartburn, indigestion, bloating, constipation, and diarrhea are the typical problems we associate with digestive system problems.
But the health of the digestive system goes beyond relieving these common symptoms.
In this Two Post series, we will talk about the ways our digestive system influences so many different aspects of our health, and the basic steps we can take to heal our gut, and ultimately, our health.
How does the Gut Become Unhealthy?
It’s important to understand, even with a good diet, we may not have a healthy digestive system.
Modern lifestyle and environmental influences on our digestive system include:
- Medications like antibiotics, NSAIDs, and steroids
- Diets high in refined sugars and carbohydrates
- Diets low in fiber
- Environmental toxins such as pesticides, herbicides, BPA, and similar substances
- Chronic stress – physical, emotional, and psychological
The Gut – More Than Digestion
As a graduate student of nutritional sciences, I enjoyed studying anatomy and physiology, biochemistry, and the science of nutrition. In my last year of graduate school, we approached the body systems from a medical nutrition therapy strategy. We studied each body system as a separate entity (cardiovascular system, immune system, nervous system, etc.) and reviewed the nutritional therapies for treating illnesses for each of these systems. Of course, this is a reductionist approach, and does not address the sophisticated ways in which the body coordinates functions across various systems. For example, the effects of chronic stress on heart disease are well-documented.
Science is beginning to better comprehend the synergistic ways the body systems function. And this understanding has led to more research into the many ways the digestive system is intimately linked to all the systems of the body.
The gut dose so much more than digest and absorb nutrients! Research is looking at the ways the digestive system is connected to:
- Mental health – including depression and anxiety
- Autoimmune disorders – type 1 diabetes, rheumatoid arthritis, allergies
- Skin disorders – eczema, psoriasis, and acne
- Metabolic conditions including type 2 diabetes and obesity
Let’s talk about some of the ways the health of our digestive system affects so many aspects of our overall health, starting with depression and anxiety.
The Gut – Brain Connection – Depression and Anxiety
Can healing your gut relieve anxiety and depression?
In her ground-breaking new book, A Mind of Your Own, Dr. Kelly Brogan presents research, past and present, demonstrating the connections between digestive health and the common symptoms of depression and anxiety.
Scientists understand the digestive system contains an amazing number of neurons that are able to send and receive messages to and from the brain. There are predicted to be over 100 million neurons lining the digestive system, and these neurons do more than manage our digestive processes. Scientists are referring to this extensive collection of neurons as our “second brain”. What is the significance of this “second brain” within our digestive system?
The majority of our mood-related hormones and neurotransmitters, including serotonin, dopamine, and endorphins are not produced in the Central Nervous System brain. These important neurotransmitters are produced in the gut.
The neurotransmitters produced in the gut are responsible for:
- Feelings of happiness
- Clarity in thinking/reducing “brain fog”
- Reducing anxiety and depression
- Diminishing pain
In other words, our digestive system is an integral part of how we process emotions, and the gut has a powerful influence on our moods and emotional states. Ever had a “gut feeling”? Science shows there is definitely something going on there!
Gut Permeability and the Immune System
Leaky Gut Syndrome
The digestive system is the largest boundary between the environment and us, even greater than our external skin surfaces. There is only a single layer of cells between our digestive tract and the bloodstream. The small intestines have the complicated and sophisticated task of moving nutrients from the intestines into the bloodstream and simultaneously keeping bacteria, toxins, and wastes out of the blood.
Between the epithelial cells that line the intestinal tract are junctions that open and close, allowing the absorption of appropriate-sized substances. These junctions between the epithelial cells can become too permeable, or “leaky”, allowing the absorption of unwanted particles. These unwanted particles cause an immune response, and leading experts are now identifying the links between gut permeability, chronic inflammation, and autoimmune disorders such as celiac disease, type 1 diabetes, multiple sclerosis, and rheumatoid arthritis.
The condition of increased gut mucosal permeability is commonly called “Leaky Gut”, because it allows unwanted substances to “leak” into the bloodstream. Symptoms of leaky gut may include:
- Weight gain
- Insulin resistance – prediabetes, diabetes
- Thyroid problems – hypothyroidism, Hashimoto’s, and Graves disease
- Menstrual cycle problems
- Autoimmune problems
- Frequent infections
- Skin conditions:
- Dermatitis herpetiformis (gluten rash)
Although it was previously believed the autoimmune process remained ongoing once activated, recent evidence indicates these conditions can improve or be reversed. Diet and gut health are an important part of this process.
Gluten and Zonulin
Zonulin is a protein in the body that functions to adjust the tightness of the connections between the epithelial cells of the small intestine. Patients with autoimmune disorders demonstrate larger quantities of zonulin, and increased spaces between epithelial cells (a “leaky gut”). Studies show that when gluten intake is reduced or eliminated, zonulin levels decrease, and the barrier between cell walls tighten. Researchers are examining the potential to decrease a number of autoimmune disorders with reduced dietary exposure to gluten.
Not everyone develops leaky gut or autoimmune disorders when exposed to gluten. Scientists believe there is likely a genetic disposition to developing leaky gut and autoimmune disorders in response to gluten.
Leaky Gut and Autoimmune Disorders
Approximately 75% of our immune system is contained within the digestive system, and the health of our gut has a huge impact on our immunity.
There are between 90-100 different known autoimmune diseases, and another 40 diseases suspected of having an autoimmune basis. The number of autoimmune diseases is on the rise, and autoimmunity is the number two leading cause of chronic illness.
The seriousness of leaky gut and the influence on chronic and acute disease is undergoing intense research. As the evidence grows linking diet, lifestyle, and environment to the health of the intestinal mucosal lining, we will gain more insight into strategies for improving our health through dietary choices. In my next post on gut health, I will offer strategies you can use to decrease the effects of leaky gut.
It has long been known that an extensive microbial world exists within our digestive systems. Originally, this was understood as a passive relationship – we give shelter and nourishment, and the microorganisms, when kept in balance, cause no harm. But our understanding is continually expanding, and we now know the microbial population within our digestive systems is essential to our health and well-being.
Our intestinal microflora is both inherited from our parents and obtained from our environment. But it does not remain static. Diet, medications, and environment cause ongoing changes to the microorganisms living within our body.
Maintaining a healthy population of microorganisms within our digestive system is linked to:
- improved digestion and nutrient absorption
- nutrient synthesis (like vitamin K)
- improving symptoms of depression
- reducing inflammation
- influences on our immune system
- preventing pathogens from colonizing the digestive tract
- a role in metabolic diseases, including diabetes and obesity
Supporting a healthy population of microflora can improve our health in significant ways, including our ability to absorb nutrients, improving our anxiety and depression, reinforcing our immune system, and supporting a healthy metabolism. Fortunately, strategies for promoting a healthy balance of microorganisms are the same for improving our general health.
In my next post, I offer simple strategies to improve the health of your digestive system, including ways to support a balanced and thriving population of gut microorganisms.
There is a lot more going on in our digestive system than simply breaking down food and absorbing nutrients. Some of the questions I considered when researching this subject:
- If we don’t have symptoms of indigestion, constipation, etc. – how do we know if our gut is healthy or not?
- If gut health is so critical for our overall wellness, how do we make sure ours is healthy?
- Is it hard to maintain a healthy gut?
- What can we do?
Do you have questions? I would love to hear them.
Please let me know, either through the comments or by email: firstname.lastname@example.org
And if you know someone who might benefit from this information, please share using your favorite social media.
Let’s continue this important conversation in tomorrow’s post.
Gut Health, Depression, Anxiety, Weight Loss and More – Part Two
Tomorrow I will share strategies to:
- Reduce leaky gut
- Reduce inflammation
- Promote healthy gut microflora
Changing your gut might change your life.
Would you like to make your own fermented foods at home, but feel overwhelmed? Corina from Marblemount Homestead will guide you through the process of making your own Greek Yogurt, Sauerkraut, Beet Kvass, Kombucha, and No Knead Bread. Corina’s simple step-by-step instructions and her fun videos show you how fun and easy fermenting foods at home can be.
You can learn more about Corina here.
Corina’s one-minute course introduction video:
Dr. Kelly Brogan, Massachusetts Institute of Technology, MA BS in Brain and Cognitive Science/Systems Neuroscience, http://kellybroganmd.com/what-you-dont-know-about-depression/
Zonulin, regulation of tight junctions, and autoimmune diseases – http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3384703/
Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines – http://www.ncbi.nlm.nih.gov/pubmed/16635908
Allergy and the gastrointestinal system – http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515351/
The Intestinal Immune System – http://gut.bmj.com/content/30/12/1679.full.pdf
Gut bacteria’s influence on our immune system http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4359909/
Intestinal permeability – a new target for disease prevention and therapy – http://www.biomedcentral.com/1471-230X/14/189
Role of the gut microbiota in immunity and inflammatory disease – http://www.nature.com/nri/journal/v13/n5/full/nri3430.html
The gut microbiota shapes intestinal immune responses during health and disease – http://www.nature.com/nri/journal/v9/n5/full/nri2515.html
Frontiers in Bioscience 14, 5107-5117, June 1, 2009 – The gut microbiota ecology: a new opportunity for the treatment of metabolic diseases? – http://download.bioon.com.cn/upload/month_0909/20090915_c43574b81cb378d099b2PwbGpZyktHrn.attach.pdf