The Gut Balance Revolution

Boost Your Metabolism, Restore Your Inner Ecology, and Lose the Weight for Good!

Look inside
Paperback
$16.99 US
On sale Jul 03, 2017 | 432 Pages | 9781623367787
Losing weight for good is truly possible with a science-based approach to gut health.

Recent cutting-edge research shows that human intestinal microbiota influence metabolism, appetite, energy, hormones, inflammation, and insulin resistance. Because gut microflora plays a central role in weight management, losing weight is much more than cutting calories, fat, or carbs. When the trillions of live bacteria in our digestive tract—the gut microbiome—are balanced, excess pounds melt away and we feel revitalized. 

A leading authority on digestive health and the gut microbiome, Dr. Gerard E. Mullin shares a proven, science-based program to restore and retain weight loss by achieving a balanced gut flora in The Gut Balance Revolution. He reveals how to stifle the fat-forming, disease-promoting gut bacteria, reseed your gut with good fat-burning ones, and fertilize those friendly flora with just the right foods to reboot, rebalance, and renew your health—and lose weight for good. It's all grounded in hard science and his over 20 years of clinical experience with patients in his medical practice. Dr. Gerry Mullin's trailblazing program provides:

• Research: The latest, up-to-date frontline science behind how balancing your gut flora can burn fat and restore health
• Reboot, Rebalance, Renew: Step-by-step meals plans, food charts, plus 50 delicious, easy recipes
• Rev Up: An exercise routine for each phase of the process
• Real Life: Bona fide success stories of people who seamlessly lost up to 40 pounds—and kept it off!
CHAPTER 1

The Hidden Secret to Weight Loss

WEED, SEED, AND FEED YOUR INNER GARDEN

Eat less and exercise more.

We've all heard it--from our doctors, on TV, on the Internet, in magazines, from friends and family. At one time or another, most of us have even tried it. But let me ask you: How has this recipe for weight loss worked for you?

It seems like such a simple formula--it matches our understanding of the physical principles of the universe. Energy in, energy out. What we don't spend, we store. It's common sense. It must be right.

There's just one small problem. It doesn't tell the whole story of why people gain weight. And it doesn't tell us how to lose it.

The calories in/calories out theory of weight loss is outdated. Modern science has proven beyond any shadow of doubt that your weight and your health are dependent on much more than how many calories you consume. You'll learn about some of this evolving science in this book. However, common sense and personal experience tell us that if weight and health were all about the amount of calories you consume each day, you could eat 1,800 calories of Oreos and Diet Coke and stay fit and healthy. But, of course, we all know that doesn't work. The food you eat has a far greater influence on your body than solely the amount of energy it provides. It has wide- ranging effects on numerous biochemical and physiological processes. While it's true that most of us could afford to eat a little less, and reducing total caloric intake is necessary to a certain point to incur weight loss, the quality of the calories you consume is far more important in the long run.

That's especially true if you want to burn fat and keep it off for good. Anyone can go on a starvation diet, burn out the treadmill, and drop a few £ds. You might even lose a couple of pants sizes or notice that you look a little better in your bathing suit. But the sad reality is that most of the £ds you drop will be water weight, and some fat-burning muscle to boot. Without altering your lifestyle and eating habits, revisiting your relationship to food, and systematically enhancing the overall quality of the calories you consume, your diet is doomed to fail in the long run.

In fact, research has shown that the vast majority of calorie-restricted diets fail long term. A study conducted at the University of California in Los Angeles showed that people who go on calorie-restricted diets typically lose 5 to 10 percent of their body weight within 6 months--but regain everything they've lost within 4 to 5 years.1

And this yo-yo effect causes downstream biological complications that make it even more difficult to lose weight in the long run. Your body is a complex ecosystem (actually, an ecosystem within an ecosystem, as we'll see shortly), and all complex biological systems have mechanisms in place to maintain homeostasis. The dictionary defines homeostasis as "the maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions." It's easy to see why this is important. If you didn't have a built-in biological mechanism for maintaining basic physiological processes such as body heat, survival would be far more complicated.

What does this have to do with weight? Well, the rate of your metabolism and the amount of fat you carry are tightly regulated by a complex array of homeostatic internal processes. Some doctors call this internal thermostat your "body weight set point," and it's influenced by a number of factors such as hormones, neurotransmitters, intestinal peptides, your gut microbiome, and more.2, 3

Several studies have shown that your body weight set point remains fairly constant, maintaining your body weight in a stable range despite minor changes in energy intake (calories in) and expenditure (calories out). It's also been shown that your body is very efficient at holding on to weight during periods of caloric deprivation. That's because your body set point has shifted downward and is telling your body that your metabolism needs to be slowed to minimize weight loss during periods of caloric deprivation. This provides a clear survival advantage but demonstrates how low-calorie diets that are based solely upon energy deprivation have short-term efficacy as the new set point limits ones weight loss. Your body weight set point will also try to keep you from gaining weight when you eat too much by burning more calories, but this effect is short lived. Overall, it's harder to lose weight than it is to gain weight--an experience many of us are all too familiar with. Yo-yo dieting is a very common result of weight- loss programs and causes one to ultimately weigh more. Yo-yo dieting has been shown to raise the body's set point, which is your brain telling your body "Hey, we ought to now weigh more to reach this new equilibrium" and sending control signals throughout your body to slow metabolism so you gain body weight and fat mass--the new normal. Thus, you weigh more than before with each failed energy-deficit diet program and it becomes harder and harder to lose weight as the set point is raised each time a weight-loss regimen fails.4

To effectively lose weight and keep it off, you need to strategically alter your body weight set point. Emerging evidence suggests that bariatric surgery, particularly gastric bypass, may work in part by helping the body establish a new set point by altering the physiology governing body weight.5 And that's the real problem with yo-yo dieting--every time your weight rebounds, your set point gets pushed higher, so your body acclimates to the new body weight set point as "the new normal." Hormonal and metabolic adaptations now make it more and more difficult to lose weight.6

Calories in/calories out doesn't work for the masses, because it can't work. It can't work, because simply reducing the amount of food you consume and spending more energy exercising doesn't necessarily influence your body weight set point. Sure, there are some people out there who can lose weight by eating less and jogging 100 miles a week, but they're the exception. We may admire (or even be a little jealous of) them, but they don't point the way for the majority of us to lose weight and stay healthy.

So if eating less and exercising more isn't a realistic, sustainable way to lose weight, what is?

This is where things get interesting. When you talk behind closed doors to doctors or scientists who specialize in metabolism, they'll reveal that we aren't 100 percent certain why there is an obesity epidemic in this country in light of the fact that we are consuming fewer calories as a nation.

Yep, you read that right. We are getting fatter, even though we are taking in fewer calories than we did a decade ago. A new study published in the American Journal of Clinical Nutrition shows that the average daily caloric consumption of Americans fell by 74 calories between 2003 and 2010. Despite this shift, obesity rates among women have stayed at a whopping 35 percent, and for men they continue to increase.7

This finding confused the authors of the study. "It's hard to reconcile what these data show, and what is happening with the prevalence of obesity," said coauthor Dr. William Dietz, former director of the division of Nutrition, Physical Activity, and Obesity at the Centers for Disease Control and Prevention.8 The data simply don't bear out the whole calories in/calories out concept.

But there's no question we're in trouble. The constellation of obesity, metabolic syndrome, and type 2 diabetes is arguably the greatest single health-care challenge in the industrialized world, and it's rapidly spreading to less-developed nations. Until a few decades ago, obesity was rare. Now the people who are obese or overweight outnumber those suffering from malnutrition. This is an unprecedented state for our species.

And it's spawned an industry of celebrity "experts," each of whom claims to have found "the single most important reason America is overweight." These people will try to convince you their special method can help every person drop many £ds overnight. Many will hype an exotic food-based supplement that no one has heard about except on celebrity talk shows, while others talk about detoxing, juicing, and bizarre rituals that grab our attention based on pure sensationalism. More evidence-based health experts deliver the message that stabilizing insulin resistance and blood sugar is key, while others focus on reducing inflammation. Other authorities tell us about the importance of balancing our hormones. Then there's the "Paleo" prophets and the vegan aficionados, and a million others.

So which of them is right? None of them and all of them.

There are many factors that lead to weight gain and weight loss. There's no question insulin resistance and blood sugar balance play a vital role, and they may indeed be one of the core reasons so many of us are overweight, exhausted, and unwell. They are the key factors in metabolic syndrome and type 2 diabetes. We also know that low-grade systemic inflammation and creeping weight gain, especially around the belly, are intimately linked. In fact, the adipose tissue that collects around the belly is inflammatory and leads to a cycle of hormonal imbalance and further weight gain. Do hormones play a role? Absolutely. Insulin, leptin, ghrelin, thyroid, and other hormones are all pieces of the weight-loss puzzle.

Recent research has even linked certain environmental toxins, such as persistent organic pollutants (POPs), to weight gain. These chemical substances--often referred to as obesogens--persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. POPs mimic hormones like estrogen that encourage your body to put on weight, and they block cellular docking stations that trigger weight loss.

Genetics plays a role, too, and so does your community--people who have good social support networks tend to weigh less and live healthier, longer lives. Yes, calories play a role and how much you eat does seem to matter, but it's not the whole picture.

And there is one, until now largely unrecognized factor that connects many of these pieces. . . .

New research is showing us that this factor has a far more profound impact on longterm weight-loss results and overall health than anybody expected. Medical scientists are beginning to find that when you balance this area of your health, weight tends to drop off more easily and your results last longer. My extensive experience as a leading digestive health specialist and medical nutritionist at The Johns Hopkins University School of Medicine bears out what this cutting-edge science is now revealing. Your gut microflora--the vast ecosystem that lives in your intestines--is a crucial factor in weight gain and illness and holds the key to permanent weight loss and vibrant health.

THE HUMAN GUT MICROBIOME: THE GARDEN OF LIFE AND KEY TO HEALTH

As human beings, we do not live in isolation. We are part of a complex social network of people who collectively interdepend on one another for just about everything. Whether it's food, mail delivery, energy to run our homes, or whatever else we want or need, we're reliant on tens of thousands of people to optimally live our lives. Modern industrialized society has evolved to a highly sophisticated synchrony of symbiosis.

The human body is not so different. It's not a sterile island but a complex network of trillions of microorganisms. These tiny beings surround us and lie deep within us, and we are utterly dependent on them for our health and well-being.

This may be difficult to fathom, since we're taught that we need to get rid of germs and maximize our hygiene to optimize our health. In fact, at the first sign of any apparent illness in childhood, we're doused with antibiotics, though medical science has little idea and virtually no research regarding the long-term consequences of these treatments.

We didn't evolve in a glass bubble, and we don't live in a germ-free world today. Nor would we want to. As you'll learn in this chapter, these microorganisms are crucial for the development of a healthy immune system and play a role in many other vital functions.

Living deep in your lower intestines is a complex ecosystem of microorganisms--a veritable garden of life. This magnificent orchard is composed of viruses, bacteria, and fungi, all of which collectively constitute what's called the human gut microbiome. When we care for this garden and nourish our flora, our health flourishes. But when we feed these microorganisms poorly and treat them poorly, the biodiversity of this ecosystem plummets and our health is compromised.

The modern movement of "going green" has taught us a lot about the importance of developing practices that support environmental sustainability. Each of us participates in a larger ecosystem, and our actions influence the health of that ecosystem. If we want our world to be healthy, we have to act in ways that help make it healthy.

But what about the ecosystem inside of you? It's something few of us think about. Just as our actions influence the ecosystem around us, they influence our ecosystem within. Balance and biodiversity in this ecosystem create health--imbalance and reduced diversity in the ecosystem create illness. There are many mechanisms by which microbes can protect us from disease or make us sick, help us lose weight or pack on the £ds, and we'll discuss many of them throughout this book. Indeed, the most important lesson is that the solution to your weight problem as well as many of the diseases we face today may never be found if research remains focused on you, the host. We must pay due attention to the host-environment interface-- the complex set of relationships that constitute the human-gut microbiome connection.

The average human being has about 100 trillion of these organisms at any given time. Although most are located in your lower intestines, you're literally bathed and surrounded by microbes. Despite the best hygiene, we carry billions of microbes that hide under fingernails, lounge between teeth, stick to our skin, coat our eyes, hang out in our hair. There are more than 600,000 bacteria living on just 1 square inch of skin. The same holds true at internal passages: your respiratory system, genitourinary system, eustachian (ear) tubes, and much more. Just like in the 1999 sci-fi movie The Matrix, the naked human eye sees only an altered reality. It's incapable of seeing the trillions of microbes that constantly surround us. How would you feel if you could see every one-celled organism?

The microflora in your gut alone weigh about 3 to 5 pounds. These microbial cells outnumber your own human cells by a factor of 10 to 1, and microbial DNA outnumbers your human DNA by 100 to 1. Take a moment to think about what that means. Inside your body, there are more bacterial cells and DNA than human cells and DNA. Do you think this might have an impact on your health?
Gerard E. Mullin, MD, is an associate professor in the department of medicine, as well as director of Integrative Gastroenterology Nutrition Services at The Johns Hopkins Hospital. Nationally and internationally renowned for his work in integrative gastroenterology and nutrition, Dr. Mullin has accumulated more than 20 years of clinical experience in the field of integrative digestive health and earned his master's degree in nutrition while in practice. He is an honorary member of the Academy of Nutrition and Dietetics and a recipient of the Grace A. Goldsmith award for lifetime achievement in nutrition. Dr. Mullin has authored hundreds of publications and several books. View titles by Gerard E. Mullin

About

Losing weight for good is truly possible with a science-based approach to gut health.

Recent cutting-edge research shows that human intestinal microbiota influence metabolism, appetite, energy, hormones, inflammation, and insulin resistance. Because gut microflora plays a central role in weight management, losing weight is much more than cutting calories, fat, or carbs. When the trillions of live bacteria in our digestive tract—the gut microbiome—are balanced, excess pounds melt away and we feel revitalized. 

A leading authority on digestive health and the gut microbiome, Dr. Gerard E. Mullin shares a proven, science-based program to restore and retain weight loss by achieving a balanced gut flora in The Gut Balance Revolution. He reveals how to stifle the fat-forming, disease-promoting gut bacteria, reseed your gut with good fat-burning ones, and fertilize those friendly flora with just the right foods to reboot, rebalance, and renew your health—and lose weight for good. It's all grounded in hard science and his over 20 years of clinical experience with patients in his medical practice. Dr. Gerry Mullin's trailblazing program provides:

• Research: The latest, up-to-date frontline science behind how balancing your gut flora can burn fat and restore health
• Reboot, Rebalance, Renew: Step-by-step meals plans, food charts, plus 50 delicious, easy recipes
• Rev Up: An exercise routine for each phase of the process
• Real Life: Bona fide success stories of people who seamlessly lost up to 40 pounds—and kept it off!

Excerpt

CHAPTER 1

The Hidden Secret to Weight Loss

WEED, SEED, AND FEED YOUR INNER GARDEN

Eat less and exercise more.

We've all heard it--from our doctors, on TV, on the Internet, in magazines, from friends and family. At one time or another, most of us have even tried it. But let me ask you: How has this recipe for weight loss worked for you?

It seems like such a simple formula--it matches our understanding of the physical principles of the universe. Energy in, energy out. What we don't spend, we store. It's common sense. It must be right.

There's just one small problem. It doesn't tell the whole story of why people gain weight. And it doesn't tell us how to lose it.

The calories in/calories out theory of weight loss is outdated. Modern science has proven beyond any shadow of doubt that your weight and your health are dependent on much more than how many calories you consume. You'll learn about some of this evolving science in this book. However, common sense and personal experience tell us that if weight and health were all about the amount of calories you consume each day, you could eat 1,800 calories of Oreos and Diet Coke and stay fit and healthy. But, of course, we all know that doesn't work. The food you eat has a far greater influence on your body than solely the amount of energy it provides. It has wide- ranging effects on numerous biochemical and physiological processes. While it's true that most of us could afford to eat a little less, and reducing total caloric intake is necessary to a certain point to incur weight loss, the quality of the calories you consume is far more important in the long run.

That's especially true if you want to burn fat and keep it off for good. Anyone can go on a starvation diet, burn out the treadmill, and drop a few £ds. You might even lose a couple of pants sizes or notice that you look a little better in your bathing suit. But the sad reality is that most of the £ds you drop will be water weight, and some fat-burning muscle to boot. Without altering your lifestyle and eating habits, revisiting your relationship to food, and systematically enhancing the overall quality of the calories you consume, your diet is doomed to fail in the long run.

In fact, research has shown that the vast majority of calorie-restricted diets fail long term. A study conducted at the University of California in Los Angeles showed that people who go on calorie-restricted diets typically lose 5 to 10 percent of their body weight within 6 months--but regain everything they've lost within 4 to 5 years.1

And this yo-yo effect causes downstream biological complications that make it even more difficult to lose weight in the long run. Your body is a complex ecosystem (actually, an ecosystem within an ecosystem, as we'll see shortly), and all complex biological systems have mechanisms in place to maintain homeostasis. The dictionary defines homeostasis as "the maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions." It's easy to see why this is important. If you didn't have a built-in biological mechanism for maintaining basic physiological processes such as body heat, survival would be far more complicated.

What does this have to do with weight? Well, the rate of your metabolism and the amount of fat you carry are tightly regulated by a complex array of homeostatic internal processes. Some doctors call this internal thermostat your "body weight set point," and it's influenced by a number of factors such as hormones, neurotransmitters, intestinal peptides, your gut microbiome, and more.2, 3

Several studies have shown that your body weight set point remains fairly constant, maintaining your body weight in a stable range despite minor changes in energy intake (calories in) and expenditure (calories out). It's also been shown that your body is very efficient at holding on to weight during periods of caloric deprivation. That's because your body set point has shifted downward and is telling your body that your metabolism needs to be slowed to minimize weight loss during periods of caloric deprivation. This provides a clear survival advantage but demonstrates how low-calorie diets that are based solely upon energy deprivation have short-term efficacy as the new set point limits ones weight loss. Your body weight set point will also try to keep you from gaining weight when you eat too much by burning more calories, but this effect is short lived. Overall, it's harder to lose weight than it is to gain weight--an experience many of us are all too familiar with. Yo-yo dieting is a very common result of weight- loss programs and causes one to ultimately weigh more. Yo-yo dieting has been shown to raise the body's set point, which is your brain telling your body "Hey, we ought to now weigh more to reach this new equilibrium" and sending control signals throughout your body to slow metabolism so you gain body weight and fat mass--the new normal. Thus, you weigh more than before with each failed energy-deficit diet program and it becomes harder and harder to lose weight as the set point is raised each time a weight-loss regimen fails.4

To effectively lose weight and keep it off, you need to strategically alter your body weight set point. Emerging evidence suggests that bariatric surgery, particularly gastric bypass, may work in part by helping the body establish a new set point by altering the physiology governing body weight.5 And that's the real problem with yo-yo dieting--every time your weight rebounds, your set point gets pushed higher, so your body acclimates to the new body weight set point as "the new normal." Hormonal and metabolic adaptations now make it more and more difficult to lose weight.6

Calories in/calories out doesn't work for the masses, because it can't work. It can't work, because simply reducing the amount of food you consume and spending more energy exercising doesn't necessarily influence your body weight set point. Sure, there are some people out there who can lose weight by eating less and jogging 100 miles a week, but they're the exception. We may admire (or even be a little jealous of) them, but they don't point the way for the majority of us to lose weight and stay healthy.

So if eating less and exercising more isn't a realistic, sustainable way to lose weight, what is?

This is where things get interesting. When you talk behind closed doors to doctors or scientists who specialize in metabolism, they'll reveal that we aren't 100 percent certain why there is an obesity epidemic in this country in light of the fact that we are consuming fewer calories as a nation.

Yep, you read that right. We are getting fatter, even though we are taking in fewer calories than we did a decade ago. A new study published in the American Journal of Clinical Nutrition shows that the average daily caloric consumption of Americans fell by 74 calories between 2003 and 2010. Despite this shift, obesity rates among women have stayed at a whopping 35 percent, and for men they continue to increase.7

This finding confused the authors of the study. "It's hard to reconcile what these data show, and what is happening with the prevalence of obesity," said coauthor Dr. William Dietz, former director of the division of Nutrition, Physical Activity, and Obesity at the Centers for Disease Control and Prevention.8 The data simply don't bear out the whole calories in/calories out concept.

But there's no question we're in trouble. The constellation of obesity, metabolic syndrome, and type 2 diabetes is arguably the greatest single health-care challenge in the industrialized world, and it's rapidly spreading to less-developed nations. Until a few decades ago, obesity was rare. Now the people who are obese or overweight outnumber those suffering from malnutrition. This is an unprecedented state for our species.

And it's spawned an industry of celebrity "experts," each of whom claims to have found "the single most important reason America is overweight." These people will try to convince you their special method can help every person drop many £ds overnight. Many will hype an exotic food-based supplement that no one has heard about except on celebrity talk shows, while others talk about detoxing, juicing, and bizarre rituals that grab our attention based on pure sensationalism. More evidence-based health experts deliver the message that stabilizing insulin resistance and blood sugar is key, while others focus on reducing inflammation. Other authorities tell us about the importance of balancing our hormones. Then there's the "Paleo" prophets and the vegan aficionados, and a million others.

So which of them is right? None of them and all of them.

There are many factors that lead to weight gain and weight loss. There's no question insulin resistance and blood sugar balance play a vital role, and they may indeed be one of the core reasons so many of us are overweight, exhausted, and unwell. They are the key factors in metabolic syndrome and type 2 diabetes. We also know that low-grade systemic inflammation and creeping weight gain, especially around the belly, are intimately linked. In fact, the adipose tissue that collects around the belly is inflammatory and leads to a cycle of hormonal imbalance and further weight gain. Do hormones play a role? Absolutely. Insulin, leptin, ghrelin, thyroid, and other hormones are all pieces of the weight-loss puzzle.

Recent research has even linked certain environmental toxins, such as persistent organic pollutants (POPs), to weight gain. These chemical substances--often referred to as obesogens--persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. POPs mimic hormones like estrogen that encourage your body to put on weight, and they block cellular docking stations that trigger weight loss.

Genetics plays a role, too, and so does your community--people who have good social support networks tend to weigh less and live healthier, longer lives. Yes, calories play a role and how much you eat does seem to matter, but it's not the whole picture.

And there is one, until now largely unrecognized factor that connects many of these pieces. . . .

New research is showing us that this factor has a far more profound impact on longterm weight-loss results and overall health than anybody expected. Medical scientists are beginning to find that when you balance this area of your health, weight tends to drop off more easily and your results last longer. My extensive experience as a leading digestive health specialist and medical nutritionist at The Johns Hopkins University School of Medicine bears out what this cutting-edge science is now revealing. Your gut microflora--the vast ecosystem that lives in your intestines--is a crucial factor in weight gain and illness and holds the key to permanent weight loss and vibrant health.

THE HUMAN GUT MICROBIOME: THE GARDEN OF LIFE AND KEY TO HEALTH

As human beings, we do not live in isolation. We are part of a complex social network of people who collectively interdepend on one another for just about everything. Whether it's food, mail delivery, energy to run our homes, or whatever else we want or need, we're reliant on tens of thousands of people to optimally live our lives. Modern industrialized society has evolved to a highly sophisticated synchrony of symbiosis.

The human body is not so different. It's not a sterile island but a complex network of trillions of microorganisms. These tiny beings surround us and lie deep within us, and we are utterly dependent on them for our health and well-being.

This may be difficult to fathom, since we're taught that we need to get rid of germs and maximize our hygiene to optimize our health. In fact, at the first sign of any apparent illness in childhood, we're doused with antibiotics, though medical science has little idea and virtually no research regarding the long-term consequences of these treatments.

We didn't evolve in a glass bubble, and we don't live in a germ-free world today. Nor would we want to. As you'll learn in this chapter, these microorganisms are crucial for the development of a healthy immune system and play a role in many other vital functions.

Living deep in your lower intestines is a complex ecosystem of microorganisms--a veritable garden of life. This magnificent orchard is composed of viruses, bacteria, and fungi, all of which collectively constitute what's called the human gut microbiome. When we care for this garden and nourish our flora, our health flourishes. But when we feed these microorganisms poorly and treat them poorly, the biodiversity of this ecosystem plummets and our health is compromised.

The modern movement of "going green" has taught us a lot about the importance of developing practices that support environmental sustainability. Each of us participates in a larger ecosystem, and our actions influence the health of that ecosystem. If we want our world to be healthy, we have to act in ways that help make it healthy.

But what about the ecosystem inside of you? It's something few of us think about. Just as our actions influence the ecosystem around us, they influence our ecosystem within. Balance and biodiversity in this ecosystem create health--imbalance and reduced diversity in the ecosystem create illness. There are many mechanisms by which microbes can protect us from disease or make us sick, help us lose weight or pack on the £ds, and we'll discuss many of them throughout this book. Indeed, the most important lesson is that the solution to your weight problem as well as many of the diseases we face today may never be found if research remains focused on you, the host. We must pay due attention to the host-environment interface-- the complex set of relationships that constitute the human-gut microbiome connection.

The average human being has about 100 trillion of these organisms at any given time. Although most are located in your lower intestines, you're literally bathed and surrounded by microbes. Despite the best hygiene, we carry billions of microbes that hide under fingernails, lounge between teeth, stick to our skin, coat our eyes, hang out in our hair. There are more than 600,000 bacteria living on just 1 square inch of skin. The same holds true at internal passages: your respiratory system, genitourinary system, eustachian (ear) tubes, and much more. Just like in the 1999 sci-fi movie The Matrix, the naked human eye sees only an altered reality. It's incapable of seeing the trillions of microbes that constantly surround us. How would you feel if you could see every one-celled organism?

The microflora in your gut alone weigh about 3 to 5 pounds. These microbial cells outnumber your own human cells by a factor of 10 to 1, and microbial DNA outnumbers your human DNA by 100 to 1. Take a moment to think about what that means. Inside your body, there are more bacterial cells and DNA than human cells and DNA. Do you think this might have an impact on your health?

Author

Gerard E. Mullin, MD, is an associate professor in the department of medicine, as well as director of Integrative Gastroenterology Nutrition Services at The Johns Hopkins Hospital. Nationally and internationally renowned for his work in integrative gastroenterology and nutrition, Dr. Mullin has accumulated more than 20 years of clinical experience in the field of integrative digestive health and earned his master's degree in nutrition while in practice. He is an honorary member of the Academy of Nutrition and Dietetics and a recipient of the Grace A. Goldsmith award for lifetime achievement in nutrition. Dr. Mullin has authored hundreds of publications and several books. View titles by Gerard E. Mullin