SUPER
GUT
A Four-Week Plan to Reprogram Your Microbiome,
Restore Health, and Lose Weight
WILLIAM DAVIS, MD
NEW YORK
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This book is intended as a reference volume only, not as a medical manual. The
information given here is designed to help you make informed decisions about your
health. It is not intended as a substitute for any treatment that may have been prescribed
by your doctor. If you suspect that you have a medical problem, we urge you to seek
competent medical health care.
Mention of specific companies, organizations, or authorities in this book does not
imply endorsement by the author or publisher, nor does mention of specific companies,
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Internet addresses and telephone numbers given in this book were accurate at
the time it went to press.
Copyright © 2022 by William Davis, MD
Cover design by Sara Wood
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Library of Congress Cataloging-in-Publication Data
Names: Davis, William, 1957– author.
Title: Super gut : a four-week plan to reprogram your microbiome, restore health, and
lose weight / William Davis, MD.
­ ibliographical
Description: First edition. | New York : Hachette Go, 2022. | Includes b
references and index.
Identifiers: LCCN 2021035884 | ISBN 9780306846977 (hardcover) |
ISBN 9780306846953 (ebook)
Subjects: LCSH: Gastrointestinal system—Microbiology. | Health.
Classification: LCC QR171.G29 D38 2022 | DDC 612.3/2—dc23
LC record available at https://lccn.loc.gov/2021035884
ISBNs: 978-0-306-84697-7 (hardcover), 978-0-306-84695-3 (ebook)
Printed in the United States of America
LSC-C
10 9 8 7 6 5 4 3 2 1
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INTRODUCTION
Dr. Frankenstein: “You know, I don’t mean to embarrass you,
but I’m a rather brilliant surgeon. Perhaps I can help you with
that hump.”
Igor: “What hump?”
Young Frankenstein, 1974
I
n Mary Shelley’s tale of Frankenstein , through bumbling
experiments and a crude stitching together of body parts electrified
to life, Dr. Victor Frankenstein creates a monster, unnatural and not entirely human, a creature terrible to behold who escapes to terrorize the
countryside.
Nobody here is stitching loose heads and arms to torsos or passing 220
volts through organs to bring them back to life. Instead, a peculiar alchemy
of human health has been occurring these last fifty years or so, creating
modern health horrors all during a time—most of us have believed—of
unprecedented medical advancement. So it’s all the more surprising that
a universe of primitive creatures dwelling directly below our diaphragm,
behind our belly button, but beneath our conscious awareness—and that of
our doctors—is only now coming to light as a hugely important phenomenon in human health.
xi
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Introduction
Eleven years ago, in the first of my series of Wheat Belly books, I described how agricultural scientists and farmers had changed this plant
called “wheat,” transforming a traditional five-foot-tall plant into an
eighteen-inch-tall, thick-stalked, large-seeded crop, a change that required
thousands of genetic experiments. The final genetically altered result did
indeed produce a high-yield crop, enabling farmers to harvest several-fold
more bushels per acre than of traditional strains, a boom in yield that
helped feed the hungry in starvation-plagued underdeveloped countries.
But this new crop also inflicted a collection of unexpected effects on
the humans who consumed it, effects ranging from appetite stimulation
to temporal lobe seizures, seborrhea to a 400 percent increase in celiac
disease. Formerly rare type 1 and type 2 diabetes became mainstream
conditions, and humans who used to eat to live were transformed into
a population with insatiable all-you-can-eat appetites. The health consequences of consuming modern wheat are so destructive, so unnatural, that
I labeled it “Frankengrain.”
I found that removing Frankengrains from the diet yielded substantial,
often life-changing, health benefits. Thousands of people experienced effortless weight loss and transformations in their health, restoring them to
1950s-like flat tummies and freeing them of numerous modern health conditions. And yet, a substantial proportion also reported something like this:
“I lost forty-seven pounds without even trying, and I’m no longer hungry
all the time. I am no longer prediabetic and I’m off two blood pressure
pills. My rheumatoid arthritis is about 70 percent better and I was able
to stop the several-thousand-dollar-per-month injectable drug. But I still
have some flare-ups and had to resume the steroids and naproxen.” In other
words, removing Frankengrains from the diet and adding in the handful of
nutritional supplements I recommended, which reversed health phenomena such as insulin resistance, did not fully address all of people’s health
issues. Some people reported losing, say, seventy pounds, with only another
thirty pounds to go—but their weight loss stalled despite doing everything
right. The Wheat Belly lifestyle includes basic efforts to recultivate healthy
microbial species dwelling in the gastrointestinal tract, that is, the intestinal
microbiome, but something was still missing.
The Wheat Belly community, large, international, and enthusiastically
engaged, was also (and remains) a collaborative community, all of us sharing
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experiences and looking for better answers on how to achieve 100 percent
success and finally conquer residual health issues. This community, in effect, is an enormous crowdsourcing of wisdom, with hundreds of thousands
of people all seeking answers to similar questions. (Don’t worry: if you are
unfamiliar with the strategies of the Wheat Belly lifestyle, which, despite
its shortfalls, is still quite powerful, I articulate its tenets later in the book
in addition to introducing new and powerful strategies you can use to build
a Super Gut.)
Over the last few decades, outside the Wheat Belly experience, an
explosion of research made it clear that common mental and emotional
struggles such as depression, social isolation, hatred, anxiety, and attention deficit hyperactivity disorder (ADHD) could be blamed on disruptions
to the intestinal microbiome. It also became clear that health conditions
as unrelated as obesity, autoimmune conditions, and neurodegenerative
diseases likewise could be blamed on changes inflicted on the microbes
dwelling beneath our diaphragms. Because I am personally interested in
both improving human health and performance and decreasing people’s
reliance on the health-care system, I wondered whether such microbiome
disruptions could explain the persistence of health issues in the individuals
who were following my programs. It was this chain of logic that sent me
searching for evidence of lost microbes, bacterial species that might have
vanished from the modern human microbiome. And, indeed, I did find several candidates that, when restored to the human gut, yielded impressive
improvements in people’s health, and even in their appearance.
But I also found that the disappearance of several key microbes could
not explain all persistent health problems. Hints of a more comprehensive
answer kept trickling in from the worldwide Wheat Belly community as
some people continued to complain about their sleep struggles, persistent
joint pain even after partial relief with wheat and grain elimination, and
stubborn food intolerances from before the Wheat Belly program that
would not resolve. Why would so many people have intolerances to everyday foods such as tomatoes, kidney beans, and peanuts? Digging into
the idea that disrupted microbiomes could also account for these health
phenomena made it clearer and clearer that I’d find the answers in the
microbial universe. Then additional developments, such as the availability
of a smartphone-enabled consumer device that can detect microbial gas
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production in the breath, clinched it: the answers would come from the
microbiome.
I wanted to discover ways to put the power of a healthy microbiome to
work beyond the usual “take a probiotic and get plenty of fiber.” I wanted to
address not just people’s residual health problems but also ways they could
supercharge their health to reach new heights of day-to-day functioning.
I am certain beyond any doubt that modern lifestyles have disrupted
the composition of microbes in the human gastrointestinal (GI) tract, and
these microbial imbalances are to blame for the residual health issues the
Wheat Belly community and others were encountering. Modern lifestyle
factors that disturb our inner ecosystem are also responsible for a long
list of other health problems—no body system is immune to the effects
of this monster we have created called the modern human microbiome.
The microbiome of our hunter-gatherer ancestors and that of our predecessors just fifty years ago were very different from the one we have today. A combination of factors associated with modern life—from modern
processed foods to stomach acid–blocking drugs—has created a gut that
is almost no longer human; it’s something I call a “Frankenbelly,” and it’s
as destructive to our health or perhaps more so than Frankengrain. Real
health horrors result from a Frankenbelly: from irritable bowel syndrome
and constipation to ulcerative colitis and Crohn’s disease, from polycystic
ovary syndrome and colon cancer to depression and despair, from social
isolation to thoughts of suicide. These are all effects of this thing we, as a
society and as individuals, have created: a Frankenbelly of disruptions in
the microbiome.
Now we have to figure out how to kill off this thing and resurrect something closer to the natural human condition. Unfortunately, the medical
community is poorly equipped to handle the ailments resulting from a
disturbed microbiome, never mind understand their source. Rather than
address the proliferation of unhealthy bacterial and fungal species responsible for generating dark emotions, anxiety, and suicidal impulses, doctors
prescribe antidepressant and antianxiety medications to block their effects.
Rather than chart the location of errant microbes that underlies conditions
like hypertension and atrial fibrillation, they prescribe medications that
push blood pressure down and suppress abnormal heart rhythms. Rather
than decipher the microbial disruptions that cause weight gain and type 2
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diabetes, they resort to gastric bypass and medications that forcibly regulate blood sugar. All these conventional but misguided efforts also come,
of course, with a considerable price tag and long lists of side effects. I’m
sure you can appreciate the fact that coming to an understanding of all
the ­microbial havoc that’s been inflicted on modern humans will turn our
entire idea of health and disease topsy-turvy. Solutions will be different,
too—we will certainly need tools beyond those you can obtain through
your doctor’s prescription pad.
We need to rebuild the very microbial core of our health to achieve
freedom from disease and to regain youthfulness and overall quality of life.
And you know what? The sorts of benefits we can reap from restoring the
healthy human microbiome will go farther than just relief from, say, being
overweight or having acid reflux. The strategies that I shall share with you
can also yield smoother skin, accelerated healing, and increased feelings of
empathy for other people—benefits that you likely had no idea originated
with the microbial universe within. First, we must reestablish order in this
monstrous microbial mess we have created, then I will show you how to
cultivate a Super Gut.
QUIT YOUR BELLYACHING
If you could ask an organism like Escherichia coli (E. coli), “What is the purpose of human life?” E. coli would answer, of course, “Your purpose is to
support me and my fellow microbes.” You may see a higher purpose to life,
but from the vantage point inside your colon or duodenum, you are little
more than a microbe factory.
All living creatures on this planet have a unique and individual microbiome: spiders and mosquitos, squirrels and chipmunks, trout and turtles.
Humans likewise have a microbiome unique to our species but that differs for each individual. But the practices of modern life—shopping in a
grocery store and eating food served from a drive-through window rather
than killing or foraging your next meal; bathing in a hot shower in place
of a dip in a lake or river; taking a course of antibiotics for a sinus infection instead of toughing it out—add up to wreak cataclysmic alterations
in the composition and location of the microbes we harbor in and on our
bodies.
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Even though the microorganisms inhabiting your GI tract don’t have
names or addresses and can’t like your Facebook page, they play a crucial role in such diverse phenomena as your level of optimism, your skin’s
appearance, your energy level, your empathy for other people, and your
romantic life. They even influence how fast you age and how long you live.
The trillions of bacterial and fungal creatures inhabiting your GI
tract have been playing a major role in the movie that is your life. Even
if you follow healthy habits and are free of modern conditions like diabetes and obesity, the creatures comprising your microbiome can still determine whether you succumb to the helplessness of Alzheimer’s dementia
or will be blowing out 105 candles on your birthday cake, surrounded by
great-great-grandchildren, with your mental capacity and memories of last
Tuesday’s social gathering intact. Few things in this world play a role so
critical yet remain so anonymous.
It wasn’t that long ago that the microbes inhabiting the human body
were thought to be important only for their role in causing infections. But
the administration of antibiotics, which has wreaked havoc on people’s microbial balance over the last century, reveals that a multitude of micro­
organisms are actually necessary for health. Bacterial species dwelling in
the GI tract, for instance, produce B vitamins such as folate and vitamin
B12, or increase feelings of love for family and friends, or stimulate vivid,
colorful dreams during the restorative rapid-eye-movement (REM) phase
of sleep, which are essential components for normal mental health.
Like it or not, all of us today are under the profound influence of
trillions of anonymous microscopic creatures. Who would have realized
even ten years ago that this collection of microorganisms can determine
whether you develop Parkinson’s disease, how rapidly you heal from an
injury, and whether you can tolerate the foibles and quirks of your spouse?
It’s unsettling to think that microscopic creatures might make the difference between writing a book that earns the Nobel Prize for Literature and
gunning down people in a church. But that is the impressive power of this
population of microbes we carry, a universe of life that can serve or work
against us.
Thankfully, many of the health struggles that can be blamed on a disrupted microbiome can be reversed simply by shifting toward a healthier
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diet, addressing common nutrient deficiencies, and restoring healthier bacterial species to the GI tract after we’ve beaten back undesirable microbes.
But what about someone who, having accumulated all the microbial
disruptions of prior years, now has a disastrous case of bacterial and fungal
overgrowth that has careened out of control? All the microbe-disruptive
factors of modern life enable the proliferation of unhealthy bacterial and
fungal species in our bodies, most concentrated in the gastrointestinal tract,
a situation labeled “dysbiosis.” Dysbiosis confined to the colon, that is, the
last five feet of the GI tract, poses risks for health conditions such as ulcerative colitis and colon cancer. But it is not uncommon for unhealthy bacterial species to ascend from the colon where they belong into the ileum,
jejunum, duodenum (parts of the small intestine), and stomach, a situation
labeled “small intestinal bacterial overgrowth,” or SIBO. The disruptions
of bacterial populations that cause SIBO often also enable fungal species
to similarly proliferate and climb up the length of the GI tract to inhabit
places they do not belong, and this condition is called “small intestinal fungal overgrowth” (SIFO). Sadly, it is the rule, rather than the exception, that
doctors fail to recognize these situations but “treat” the varied diseases they
cause that show on the surface. You can see how someone with unrecognized SIBO, for instance, who suffers from conditions that are not readily
reversible such as diverticulitis, Hashimoto’s thyroiditis, or colon cancer,
can end up taking a long list of prescription drugs and even undergoing
serious medical procedures such as gallbladder or weight loss surgery.
However, if the SIBO or SIFO is caught early enough and reversed—and
a healthy microbiome is restored—many of the accompanying chronic
conditions will fade away in the face of good health in symbiosis with a
balanced internal microbial universe.
The key, therefore, is to be keenly aware of dysbiosis, SIBO, and SIFO
and all their signs and consequences, then take action to correct these common situations. I shall show you how to recognize the telltale signs of these
conditions, how to confirm their presence, and how to deal with them. It’s
not all doom and gloom. I go several steps further to show you how to take
your healing program to new heights so that you can look in the mirror
and be proud of what you see and visit your doctor, who will be speechless
at the superior level of your health, and answer all the questions coming at
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Introduction
you from people wanting to know why and how you look so darned good:
slender, firm, muscular, with thick, moist skin, adept mental capacity, libido fully intact. Understanding and reestablishing order in your microbial
universe—shifting their population composition, limiting where they are
allowed to reside, and reducing the flood of their toxic by-products—bring
on a tsunami of positive health, weight loss, and age-reversing effects.
We are embarking on a journey that, I believe, will allow you to find
answers to questions that may have stumped doctors, who usually ignore
the fact that you have lost crucial microbes and acquired a host of unhealthy species in their place. While they continue to prescribe drug after
drug to treat the symptoms of a disturbed microbiome, offer ineffective
advice such as “move more, eat less,” and blame you for moral weakness,
gluttony, or bad genes, you will learn to recognize and address this microbial switch, and then you are on your way to magnificent health.
Dust off your yogurt maker, cancel the Botox appointment, and pull up
a chair, as you are about to go on a bacterial journey that can change the
course of your life. Let’s begin by detailing exactly how and why so much
has gone wrong in the human microbiome.
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