The Whole-Body Microbiome

How to Harness Microbes—Inside and Out—for Lifelong Health

B. Brett Finlay, Jessica M. Finlay

• Publisher: Douglas & McIntyre
• Year: 2019
• ISBN:
  9781771622219
• Topic: Ciencias biológicas
• Subtopic: Microbiología

Science has made huge leaps in prolonging life through disease prevention and treatment, but microbiologist Brett Finlay and gerontologist Jessica Finlay offer a different—and truly revolutionary—approach to the quest for the fountain ofyouth.

Microbes are the oldest and smallest forms of life on earth, and encompass bacteria, viruses, protozoa, fungi and other microscopic organisms. While some bacteria and viruses can make us sick, normally we coexist peacefully with microbes. In fact, they are essential to our everyday health. Microbes help break down food in the digestive tract, support immune function and protect us from the pathogens we come into contact with on a daily basis. Our well-being is intimately tied to the microbes that surround us—on our cellphones, kitchen sponges, houseplants, pets anddesks.

In this groundbreaking volume, the authors present current and emerging research on microbial interventions for the full gamut of age-related conditions, from sun spots and wrinkles to Alzheimer's disease, cancer, osteoporosis, menopause, chronic inflammation and more. The good news is that simple changes to nutrition and lifestyle can promote the right kind of microbial exposure, to improve health whether we're eighteen oreighty.

Incorporating interviews with leading microbiologists, scientific researchers and medical professionals, and with a compelling and proactive approach to cutting-edge science, The Whole-Body Microbiome will appeal to anyone looking to grow old as healthfully and gracefully aspossible.

1
The Fountain of Youth Is Full of . . . Microbes?

From the moment we are born, we begin to die. Aging is a universal but uniquely personal experience. It scares us, bullies us, and motivates us to live better. Because we, as a species, are living longer and longer (more than eighty years nowadays in most developed countries), every one of us has even more time than ever before to grapple with aging and mortality.

Despite what advertisements and doctors may tell us, there is no way to simply “turn back the clock,” but we still try to delay the inevitable. We all search for ways to prolong our lives and preserve our bodies—these complex machines made of muscle, bone, and a host of other tissues; our minds, our hearing and eyesight, even our looks. The mythical Fountain of Youth is a spring that allegedly restores the youth of anyone who drinks or bathes in its waters. Since the fifth century BCE, tales of such a fountain have been recounted across the world. Today is no exception—we continue the age-old quest to preserve and restore youth. Instead of seeking the hidden location of the elixir of life, however, we pursue eternal youth through science. Pharmacies, grocery stores, and cosmetic aisles are stocked with anti-aging products, ranging from serums and creams to fight wrinkles and banish spots, to vitamins and supplements promising an elusive “youthful glow.”

Scientific studies suggest myriad ways to intervene in the aging process, including antioxidants (to limit the number of free radicals, which cause age-related damage at cellular and tissue levels); calorie restriction (which extends life span and minimizes age-related chronic diseases in a variety of species including rats, mice, fish, flies, worms, and yeast); hormone supplements to treat menopausal symptoms; and a host of dermatological procedures and treatments including retinoids, chemical peels, dermabrasion, ultrasound imaging, laser resurfacing, and cosmetic surgery. While many of these methods have been touted as glamorous and high-tech, one of the most exciting frontiers of current aging science involves the oldest life forms on Earth: microbes.

Contrary to the cutting-edge scientific inventions we’re using to make alternative time-reversers, these bacteria have been around for more than 3.5 billion years, from a time when our planet was covered in oceans that regularly reached a boiling point. Our climate has changed dramatically, but microbes are still everywhere: in the air you breathe (they actually made the original oxygen in the atmosphere), on the chair you sit in, and in the food in your fridge. In fact, there are more microbes on your hand than there are people on the entire planet!

Microbes are our constant companions throughout life. Commonly known as germs, they come in many forms, including bacteria, viruses, protozoa, algae, and fungi. While we often blame them for disease (e.g., “I’ve got a stomach bug”), we have only recently realized they are in fact absolutely essential for healthy life. We could not exist without them.

But what do microbes have to do with aging? Everything, actually. We have distinct microbial communities throughout our entire bodies—not just in the gut. These communities affect how our brain, teeth, skin, heart, gut, bones, immune system, and nearly every other body part functions as we progress through life. Well-being is also intimately tied to the microbes that surround us—on our cellphones, kitchen sponges, houseplants, pets, and desks. If you move to a new home or travel abroad, you are exposed to new microbial communities that can disrupt your body’s existing microflora (for better or for worse). Your zip code is one of the best predictors of health and longevity, which is underscored by billions of invisible neighbours: microbes. Knowing that there is a continuum between you and the outside world, not a brick wall that ends at your skin, can help you stay healthier over time even if your zip code and age change.

You can harness the microbes in and around you to help keep your gums healthier, bones and muscles stronger, and possibly even protect your brain from Alzheimer’s disease and dementia. Of the top ten causes of death in the United States, we now realize microbes can play an integral role in all but one.

Microbial Involvement in Leading Causes of Death in the United States

1. Heart disease: 633,842 ***
2. Cancer: 595,930 **
3. Chronic lower respiratory diseases: 155,041 **
4. Accidents (unintentional injuries): 146,571
5. Stroke (cerebrovascular diseases): 140,323 **
6. Alzheimer’s disease: 110,561 ***
7. Diabetes: 79,535 ***
8. Influenza and pneumonia: 57,062 ***
9. Nephritis, nephrotic syndrome, and nephrosis: 49,959 **
10. Intentional self-harm (suicide): 44,193 *¹

Data for 2015 obtained from the Centers for Disease Control (2017). Asterisks (*) denote the authors’ evaluation of the strength of microbial involvement.

¹ Microbiota are closely linked to depression, which is a major cause of suicide.

In this book, we will explore and untangle these connections between disease and our bodies’ microbes to broaden your understanding of their impact on aging and mortality. Moving from head to toe—or rather skin to brain, mouth to lungs, stomach to gut, etc.—we illustrate how the invisible world of microbes around and inside our bodies is nourishing and essential to a healthy and long life. We think through improvements to lifestyle, diet, and household practices to promote the right kind of microbial exposure. Instead of homes and care environments that are as sterile as possible, for example, we envision places that are comfortable living spaces for us and our microbial roommates. Age-friendly environments need to foster the health and well-being of all inhabitants—microbes included.

Growing Old with Your Microbes

Aging is a natural process that occurs in all biological species, though for some it happens faster than for others. Biologically, we humans hit our prime at around age twelve. In other words, if your physiology (meaning your body and its functionality) remained at that age, you would live more than one thousand years! After twelve, the chance of dying doubles every eight years.

And yet our species somehow beat these odds with increasing success. We spoke to Dr. Anne Martin-Matthews, professor of sociology at the University of British Columbia and former scientific director for the Institute of Aging established by the Canadian Institutes of Health Research. She commented on our current staggering, and unprecedented, aging population: “Over the forty years of my career studying aging, we never anticipated how the field would be shaped by the extended longevity of the population. As recently as a decade or so ago, much of our research focused on ‘older people’ in their seventies and the ‘oldest old’ in their eighties. Now we all personally know a 73-year-old with a 95-year-old mother, or an 82-year-old woman concerned about her elderly husband and with a 105-year-old parent still alive!”

The advent of vaccinations, antibiotics, and improved sanitation—beginning in the early 1900s—dramatically reduced the number of childhood deaths, as well as deaths due to infectious diseases. This resulted in a major increase in longevity worldwide: Life expectancy increased from thirty-one years in 1900 to seventy-two years in 2016, with Japan’s average currently coming in highest at eighty-four! Dr. Martin-Matthews noted that the number of centenarians (older than 100) continues to increase worldwide, along with more supercentenarians (older than 110). This is one of the most significant social transformations of the twenty-first century.

While virtually every country in the world has growing numbers of older people, chronic ailments such as obesity, type 2 diabetes, asthma, and inflammatory bowel diseases are also rapidly on the rise worldwide. Far from being limited to developed regions of the world, chronic diseases are accelerating in developing countries. The number of people in the developing world with diabetes, for example, will increase by more than 2.5 times, from 84 million in 1995 to more than 228 million in 2025. The World Health Organization (WHO) estimates that the global burden of chronic disease will rise to 60 percent by the year 2020, from approximately 46 percent in 2001. Almost three-quarters of all deaths in 2020 will be attributable to chronic diseases.

These conditions plague many individuals’ health and reduce quality of later life. In terms of incidence—i.e., the number of people affected—cardiovascular disease and brain diseases such as Alzheimer’s, Parkinson’s, and dementia are on a dramatic upward trajectory in our society. But despite more than twenty years of intense research, Dr. Martin-Matthews reflected there is still no “silver bullet” to address Alzheimer’s disease and related dementias: “Research has primarily focused on the brain and its structural changes. Yet the reality is that we have not been able to find effective prevention or treatment measures. Multiple billions of dollars of research investment later, we’re coming to understand that the issue is much more complex. We clearly need to look elsewhere. Perhaps the microbiome plays a role—maybe to solve problems in the brain we need to look at the gut and other areas of the body where microbes are involved.” Dr. Martin-Matthews admits she is no microbe expert—quite the opposite, actually, as she confessed at the beginning of our interview.

And yet, as a sociologist and social scientist she is very clued-in to possible microbial interactions. Microbes affecting our brains, as well as other distinct bodily and environmental sites, are ripe for investigation given that they offer immense potential to better understand aging. Researchers with the openness of Dr. Martin-Matthews have already drawn remarkable connections between the microbiome and conditions such as obesity, type 2 diabetes, asthma, and inflammatory bowel diseases, in one way or another. They have also found links to many other normal physiological changes associated with aging, such as loss of bone and muscle mass and skin wrinkling. This research involves microbial effects well beyond the stronghold of our guts in important body sites such as the brain, heart and bones, as well as critical human environments like hospitals and nursing homes. By better understanding our everyday environmental microbes, we believe we may be able to strategically manipulate them so that we can live healthier and longer lives.

In Sickness and in Health: Microbes, Our Lifelong Partners

We are inhabited by more microbes in and on our body than we can imagine: There are at least as many bacterial cells in the body as human cells. They surround us and cover us. There are actually layers of microbes between every body surface and the environment, not only between your skin and the pages of this book, but also between the air you breathe and your lung cells. Normally we all coexist peacefully, but our microbial interface is heavily influenced by changes in our environment. Every moment has the potential to radically alter the landscape of our microbiome—and thus impact health.

Microbes are especially important at the bookends of life: the first few years of childhood and the last years of adulthood. Cohabitation with microbes begins with our journey through the birth canal, when we consume mouthfuls of bacteria. We then get a regular dose of microbes from our mothers by drinking breast milk and being held skin-to-skin. This critical microbial bolus jumpstarts our immune system and impacts brain development as we set off on our lifelong relationship with microbes. As a result, by the time we reach adulthood, there are over five hundred distinct species living at any one moment in our intestines. The microbiome is fully formed by the age of two to three.

Microbes help break down food in the digestive tract and harness energy and nutrients. They keep our immune system functioning and help protect against pathogens that we constantly come into contact with. As we age, however, the role of microbes changes. People over the age of seventy have radically altered microbial communities from when they were younger. The composition of microbiota also shifts, which may lead to detrimental effects on older people. For example, as we will see later, age causes an increase in inflammatory microbes and a decrease in helpful microbes that dampen the immune system. Collectively, this results in an increase in low-grade inflammation throughout the body causing tissue damage, a process called inflammaging. These changes can lead to greater susceptibility to diseases and a general decline in health. Knowing that microbes are central to the process at the heart of general body decline is a great discovery for science—and for all of us—and highlights the critical need to maintain and enhance our microbes as we age.

It is estimated that longevity is 25 percent genetic and 75 percent environmental. This is a profound statement: It means that we have the ability to control the majority of elements that affect our health and lifespans. Just because your parent had cancer doesn’t mean that your fate is sealed—although you may have genes that increase your likelihood of getting it. Your future is affected much more by your environmental exposures. We now realize that when we talk about the “environment” as being that which is in closest contact with our body, we actually include microbes.

It is natural for our microbiome to decline as we age, but this process has undergone a radical shift because we’ve turned our environment into a battleground for our modern crusade against “germs.” Our common understanding that some bacteria and viruses make us sick, and should be avoided, is very true. These are the notorious germs we continually battle—pneumonia and flus and skin infections. But we’ve taken that truth to an extreme that is causing us to suffer dire consequences, speeding up and exacerbating the annihilation of key microbes we likely need for longevity.

As far back as the nineteenth century, pioneering microbiologists focused on chasing the microorganisms that caused infectious diseases, including cholera, tuberculosis, and diarrhea. Scientists discovered that “germs” caused rabies, anthrax, and other infectious diseases, so the hunt for disease-causing microbes escalated. Then everything changed around the middle of the twentieth century. We developed antibiotics to rid ourselves of some disease-causing infections. While these wonder drugs have saved millions of lives, they have also led to our modus operandi to kill microbes—all of them—rather than try to learn more about them and live in harmony, as we had for most of history. Other inventions, such as hand sanitizer, antimicrobial mouth washes, and household antibacterial cleaning solutions became everyday products. “If clean is good, then cleaner must be better!” we shouted from every rooftop, billboard, TV commercial, and transit station. High on our own scientific mastery over these tiny bugs, we didn’t realize that we were sending ourselves toward current disease epidemics.

A glance around our society today reveals a completely different set of diseases than those of a hundred years ago, when infections were a major killer. Obesity, diabetes, inflammatory bowel disease, allergies, and asthma are but a few examples of conditions we now realize are partly collateral damage from our war on microbes. This is because antibiotics do not just kill off the “bad” microbes, they wipe out the “good” ones, too. This is why using antibiotics can cause diarrhea, an upset stomach, and even urinary tract infections. Taking these powerful drugs will kill off the agent of disease, but they will also leave our body vulnerable in other ways by eliminating the good microbes that protect us. We call it the “Hygiene Hangover,” or the head-splitting price we pay for our century-long bender of antimicrobial precautions.

Furthermore, our highly sanitized world remarkably reduces the overall number of microbes that we are exposed to. Every generation has fewer types of microbes in and on their bodies than the previous one. More and more of us spend our days inside sanitized and climate-controlled buildings. Our bodies’ ability to work as they were designed to, in the presence of abundant and diverse microbes, is being compromised as a result, jeopardizing a key part of continued human evolution, let alone personal health.

We evolved over millions of years with these invisible partners, and yet within two to three generations, many of them could be on their way to extinction.

The Book of Microbes: Charting Uncharted Territory

What to expect when you’re expecting to grow old? While there is an entire industry devoted to preparing expecting parents, scant resources guide us on how to grow old. Every day, more and more young adults, professionals, Baby Boomers, and family members with aging loved ones actively seek out advice and information. We mainly turn to online resources or other sources of often-outdated science on aging. The supply of legitimate and scientifically based resources indeed remains scarce—and is a key reason why we’re writing this book. What...