CHAPTER 1
THE GUT: YOUR "INSIDE TRACT" TO HEALTH AND WELLNESS
Everyone has a doctor in him or her; we just have to help it in its work. The natural healing force within each one of us is the greatest force in getting well.
--HIPPOCRATES
This book is about your gut.
No, we aren't talking about those extra inches around your middle. We're talking about your alimentary canal, your gastrointestinal (GI) tract, your inner core of life, your inside tract to health and well-being.
We know it's a hard sell. Most people have an almost overwhelming aversion to contemplating their gut--one that borders on absurdity, when you stop to think about it.
After all, we revere the hard work our hearts do for us, and our culture feeds us endless rhetoric on how important it is to protect your heart with diet, exercise, and a healthy lifestyle. We love our hearts. There is something downright romantic about the pump of life--that muscle that beats 72 times per minute and will contract approximately 2.5 billion times before it pumps its last pump and finally stops speeding our blood through their vessels. What a lovely and refined organ! What a powerhouse! What a masterful example of evolution!
And the brain? We have a nearly mystical appreciation for the human brain. We worship those 2 £ds of custardlike gray matter that resides between our ears more than we do any other system in the human body. Admittedly, it is impressive and more than a bit mysterious. Despite centuries of scientific analysis, the inner workings of this seat of human cognition and consciousness are still not particularly well understood. Indeed, the brain is a marvel of creation--one that most likely holds some of the most profound secrets about what it means to be human.
If you're like most people, you would probably be apt to ponder the inner workings of many organs and bodily systems before you would think about your gut. You may look out for your skin by staying out of the sun, contemplate the mechanisms by which your reproductive system works, or be held in awe of the complexity of your eyes, ears, nose, or tongue.
You know that the health of these various parts and systems determines much about your quality of life, and you are likely vigilant in caring for them. You may visit eye doctors and dentists annually and carefully consider the latest dietary information the media feeds you regarding heart health, but few people put that kind of energy into their gastrointestinal tract, much less become intimate with the way it functions and the impact it has on their overall health and well-being.
The result is that your inside tract often goes ignored--in some cases, until it's too late.
Perhaps we ignore the gut because its job is so gritty. Or maybe it's because we are in constant contact with it on a daily basis, so we forget it's even there--like that unrecognized employee at the office who's a real workhorse but is taken for granted. Your days revolve around your gut. You eat during the day to satisfy its hunger. You go to the bathroom to excrete the waste it creates. It's the center of your world in many ways. But it's so easy to simply let it slip one's mind.
It could also be that our society has drawn us away from the gut. People these days turn up their noses at the idea of gut instinct. We eat a Standard American Diet--SAD--that puts the gut in constant peril. (You'll learn more about this in Chapter 4.) We are practically encouraged to beat up the gut with excess antibiotics, toxic chemicals, stress, lack of exercise, and any number of other poor lifestyle choices our world makes it all too easy to embrace and very difficult to avoid. Maybe we just can't face how much we torture the poor gut.
Whatever the case, most people tend to ignore GI function. And we are all suffering because of this ignorance.
As we will explain a little later in this chapter, digestive disease has reached epidemic proportions in our society. A minimum of 60 to 70 million people suffer from some kind of digestive disease, and research presented later in this chapter suggests that even more are suffering. Seventy percent of Americans either have a digestive disease or will suffer with digestive symptoms over their lifetime. According to a study produced in 2004 by the American Gastroenterology Association, the estimated cost of digestive diseases was $141.8 billion. Digestive disease costs in 2004 accounted for 10 percent of all health care spending in the United States ($1.9 trillion, 16 percent of its gross domestic product).
This figure will not come as a shock to you if you are one of the 60 to 70 million Americans who suffer with digestive disorders. But did you know that unhealthy gut function has been linked to a multitude of other diseases and chronic health conditions as well?
What's more, an unhealthy gut has been linked to a plethora of systemic symptoms including headaches, skin conditions, joint and muscle pain, allergies, asthma, menstrual pain and irregularities, and more. Even mental illnesses like depression have been linked to gut dysfunction.
Is it possible that a part of us that's so often ignored by our culture could be the very seat of health and disease prevention? Is there really a connection between gut health and our day-to-day lives? If there is, how can we get back in touch with this inside tract to health and well-being so we can thrive once more?
In this book, we will revolutionize the way you understand health and well- being. The simple truth is this: Your gut is at the center of your being in every way imaginable. Heal your gut and you will be on the superhighway to health.
The Inner Tube of Life
The average adult human is, in essence, a 30-foot-long tube that starts at the mouth and ends at the anus. The inner lining of this tube--the gut--is your interface between the outside world and the world within.
Perhaps most importantly, your gut is the place in your body where food is broken down into its constituent elements so it can be processed and turned into the vitamins, minerals, and energy you use to live every single day of your life.
On the surface, this sounds pretty mundane. Not many people are awed by the idea that their gut digests food. You eat, it goes into your stomach, a little acid is poured on it, you get the nourishment you need, and the rest goes into the toilet. That's the end of the story, right? What's so special about this?
What's funny (and sad) is that we have become so disconnected from our inside tract that most of us believe this is essentially all that happens when we eat food. We've lost touch with the wondrous transformation that occurs when other living beings (plants and animals) that were nourished by the sun and the earth give their lives to provide us with the energy we need to live.
Consider that human beings eat a more varied diet than virtually any other species on the planet. Over tens of thousands of years, the human digestive system evolved so that it could consume millions of different species. We go around eating pretty much anything we want to all day long, and we don't even have to think too much about it. (Or at least we don't think we have to! Later on you'll learn why being attentive to what you eat should be one of your biggest priorities.)
Besides breaking down food into its constituent elements and then using those vitamins and minerals to fuel your body, your gut also acts as the first line of defense against microbes and intrusive invaders: viruses and bacteria that make you ill. Seventy percent of your protective immune system cells and antibodies live in your gastrointestinal (GI) tract, and they work hard every day to keep out foreign cells that would leach out your life force.
To accomplish these tasks, your GI tract supports an entire ecosystem of its own. Trillions of bacteria live inside your gut. Most counts suggest that there are about 500 different species of bacteria living in there and that the average healthy adult carries 5 to 8 £ds of "flora" inside them at all times. The total number of bacteria in your gut exceeds the number of cells in the rest of your body by a factor of 10. In a strange way, we are more bacteria than human--more bug than human. An entire universe of beings lives inside us. This "microflora" is like an organ within an organ-- an undiscovered country of organisms that live in harmony with us.
Under normal, healthy conditions, these bacteria are "friendly" helpers that assist us in the task of living. They have a number of important jobs that we will discuss in detail later in this book, but one of their main functions is to help you digest and process the foods you eat. Chewing, stomach acid, and even enzymes by themselves don't do the trick; we need our little symbiotic friends to helps us transform our victuals into the vital substances needed for our bodies.
Your gut provides a safe shelter for these "friendly" bacteria. However, the sanctity of their home is constantly being challenged by pathogens, aka "bad" bacteria that would very much like to take up residence there. In this war for space, the army that's getting fed the best typically triumphs. When you eat too many poor-quality foods that are filled with sugar and low in fiber (foods the "bad" bugs thrive on), take too many antibiotics, or don't get enough exercise, you set the stage for the microbial terrain of your gut to shift in unhealthy ways. The "bad" bugs overtake the "good" bugs, and the results can be harmful to your health.
But this is not the only thing that can go wrong in the gut.
In addition to supporting this ecosystem of friendly bugs, your gut also has a brain of its own that it uses to take care of the digestive functions in your body. This enteric nervous system (ENS) has garnered much attention in recent years, particularly due to the work of Dr. Michael Gershon, an internationally renowned neuroscientist who coined the term "the second brain" for the ENS. Yet most people still aren't aware of the miraculous work the gut-mind performs.1
Half of all the nerve cells in your body actually reside in your gut. There are more nerve cells in your bowel than in your spine. A lot of people are pretty amazed by this, because most of us think of the brain as Grand Central Station for our bodies. Maybe we live a little too much in our heads and need to get back to the center of our being--the gut.
Neurotransmitters (chemicals that allow neurons to communicate with one another) are also found en masse in your gut. Your gut has the same number of neurotransmitters as your brain, and every class of neurotransmitter in your brain can also be found in your gut.
YOUR SECOND BRAIN
You've had "gut instincts" and "gut feelings," but what you may not realize is that your gut literally has a mind of its own--the enteric nervous system (ENS). The word enteric means "of or having to do with the small intestine," which is precisely where this second nervous system is located.
Except for your brain, your gut is the only system in your body that has its own dedicated nervous system. In fact, your ENS is highly integrated into your central nervous system, and it interacts with it constantly. If you're afraid, your gut-brain knows it and your digestion is altered. Likewise, if you eat something that "doesn't sit well with you," it may put you in a bad mood.
German psychologist Gerd Gigerenzer called the enteric nervous system the "intelligence of the unconscious." So the next time your gut tells you something, listen to it. It knows more than you think.
Your gut-brain, or "second brain," commands the functions of digestion independent of your actual brain. This is absolutely amazing when you think about it. In grade school, most of us were taught that the brain controls all the functions of the body--like a commander overseeing its troops, the brain is thought to tell every other cell in the body what to do. This turns out not to be the case. The ENS can function autonomously from the brain. And yet, it is connected to it. Your brain and your gut are actually in constant communication through the vagus nerve. This nerve starts in your brain stem, runs through your neck and chest, and ends in your abdomen. It's a highway of information that connects your gut-brain to your brain, ensuring that both are in constant communication.
Little wonder then that stress, anger, anxiety, depression, and other negative emotions have a profound impact on gut health. When you perceive something as stressful, your brain tells your gut about it, and it usually doesn't react so well.
By the same token, your ENS can perceive stressful events without the help of your brain. You know those butterflies you experience when you get nervous? When your gut gets stressed-out, it tells your brain about it, too. Again, the results usually aren't so great.
These are but a few of the ways the gut acts as your interface between the outside world and the world within. (You will learn more about digestive biology throughout this book. In Chapter 2, we will give you a complete anatomical overview of the gut; we'll review gut flora, the gut-immune system, the ENS, and the rest of the digestive system in more detail.) What you may be unaware of is that you sense the world with your gut as much as you do with your brain. In fact, your inside tract is exquisitely sensitive to everything you absorb in your environment, from the foods you eat to the stress you experience to the toxins you ingest. Our gut function and our gut feelings are absolutely essential to healing ourselves and our world.
The sad and ironic reality is that, as a society, we are out of touch with the importance of maintaining good gut health, and we believe that it is okay to eat junk while taking acid blockers to try and maintain optimal digestive health and well-being. The result is an epidemic of gut-related diseases that are destroying the health of our society and wreaking havoc for many of us. Despite the fact that we live in a wonderland of medical miracles, we have lost touch with some simple truths about health and wellness that humanity has been aware of for millennia.
We need to get back on track.
Ancient Secrets to Health: The Importance of the Gut in Ayurveda and Traditional Chinese Medicine
The idea that the human digestive system is the key to balanced health and vitality has been the basis of Eastern civilization healing practices for centuries. Let's consider a couple of examples.
Copyright © 2011 by Gerard E. Mullin, MD, and Kathie Madonna Swift, MS, RD, LDN. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.