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B. Brett Finlay, (born 4 April 1959) is a Canadian microbiologist known for his contributions to understanding how microbes cause disease in people and developing new tools for fighting infections, as well as the role the microbiota plays in human health and disease. Science.ca describes him as one of the world's foremost experts on the molecular understanding of the ways bacteria infect their hosts.
Books:
Let Them Eat Dirt: Saving Our Children from an Oversanitized World (Greystone, 2016) co-authored with Marie Claire Arrieta
The Whole-Body Microbiome: How to Harness Microbes—Inside and Out—for Lifelong Health (Douglas & McIntyre, 2017) $26.95 9781771622202. Co-authored with Jessica M. Finlay
The Microbiome Master Key: Harness Your Microbes to Unlock Whole-Body Health and Lifelong Vitality (Douglas & McIntyre, 2025) $26.95 9781771624428. Co-authored with Jessica M. Finlay
[BCBW 2025]
REVIEWS
Review by Sandi Ratch
Most of us go through our daily lives not realizing that we have an army of microbe helpers that allow us to survive and thrive.
Microbes are both good and bad: the bad ones will kill us if they get out of control, and without the good ones we would succumb to some sort of infection.
If we had no microbes, we’d be fine only if we lived in a bubble, not in the real world.
So how do we allow the good microbes to help us, while keeping the bad ones in check?
The Whole-Body Microbiome, by UBC microbiologist B. Brett Finlay and Jessica M. Finlay, a specialist in health and medical geography, summarizes studies concerning how microbes in and on our bodies help us live our daily lives, and how, if they are not thriving, our health can be greatly affected.
For decades now we have all understood that the gut is full of microbes that can both help and potentially hurt us (e.g. Acidophilus is good; C. difficile is bad). Many people have found relief for illnesses like Irritable Bowel Syndrome in the form of a probiotic capsule. But this book shows us that microbes affect all parts of our bodies, not just the gut.
The authors travel, chapter by chapter, through the human body discussing how microbes help create health and disease. The first fact that jumped out at me was that there are as many bacterial cells in the body as human cells. Think about that for a second. Half of the cells that help us live, and that are in and on our bodies, are bacterial. How can that many active cells be with us and not affect our health?
All parts of the body are in touch with microbes—even the deepest parts of our lungs (a place only recently believed to be bacteria free). From the brain to the heart and lungs, from the digestive system to the skeleton, muscles, and skin, studies on all areas are summarized here. Illnesses and disorders as varied as obesity, inflammation, multiple sclerosis, kidney stones, autoimmune diseases, and cancer are discussed with regard to the microbiome.
Having a 15-year-old son at home, I was quite struck by the discussion in The Whole-Body Microbiome about how Cutibacterium acnes on the skin helps to fight acne.
And having a life-long obsession with oral health, I found it good reinforcement to read that because of oral bacteria, “individuals who do not brush their teeth daily have a 22 to 65 percent greater risk of developing dementia than those who brush their teeth three times a day!”
Our understanding of how certain interactions occur is changing with new research, for example into the links between cardiovascular disease (CVD) and red meat. It’s not the meat or the fat (and certainly not the cholesterol in the meat) so much as the microbes in the meat that seem to be the culprit:
When you eat red meat, the microbiota in the meat itself convert components of meat into specific compounds… the liver then converts these compounds into a derivative compound … which then causes plaque accumulation and CVD. Without red meat and its accompanying microbes, these compounds are not made, which drastically reduces the incidence of CVD and stroke.
With new information like this, our approach to health will certainly be changing drastically over the coming decades.
Since this is a relatively new field of study, a lot of the information in this book is preliminary. Most of the studies referenced have been done on mice or small numbers of people, but the preliminary results point to the need for further research and suggest changes that can make a difference in your health.
The main changes the authors recommend might sound familiar:
• Establish and maintain a healthy diet — yo-yo dieting does not work, partly because the microbiome has a memory and tries to get you back to your former stasis.
• Do your research before committing to a probiotic— there are some good ones for certain conditions, but there are a lot of useless products out there as well. Keep an eye out in the future for better probiotics.
• Consume different kinds of fibre (prebiotics).
• Don’t take antibiotics unless you need to — get medical tests to make sure you have a bacterial infection that could benefit from the right antibiotic. Also, use probiotics, prebiotics, and diet to help.
The Whole Body Microbiome is a revealing and interesting read, written for the general public and accessible to all. This up-and-coming scientific discipline of microbe management could help us all in the future. Let’s just hope it doesn’t unleash some mysterious and undesirable Kraken!
Sandi Ratch is a writer and heritage consultant with a masters degree in Archaeology from Simon Fraser University.
***
Books:
Let Them Eat Dirt: Saving Our Children from an Oversanitized World (Greystone, 2016) co-authored with Marie Claire Arrieta
The Whole-Body Microbiome: How to Harness Microbes—Inside and Out—for Lifelong Health (Douglas & McIntyre, 2017) $26.95 9781771622202. Co-authored with Jessica M. Finlay
The Microbiome Master Key: Harness Your Microbes to Unlock Whole-Body Health and Lifelong Vitality (Douglas & McIntyre, 2025) $26.95 9781771624428. Co-authored with Jessica M. Finlay
[BCBW 2025]
REVIEWS
Review by Sandi Ratch
Most of us go through our daily lives not realizing that we have an army of microbe helpers that allow us to survive and thrive.
Microbes are both good and bad: the bad ones will kill us if they get out of control, and without the good ones we would succumb to some sort of infection.
If we had no microbes, we’d be fine only if we lived in a bubble, not in the real world.
So how do we allow the good microbes to help us, while keeping the bad ones in check?
The Whole-Body Microbiome, by UBC microbiologist B. Brett Finlay and Jessica M. Finlay, a specialist in health and medical geography, summarizes studies concerning how microbes in and on our bodies help us live our daily lives, and how, if they are not thriving, our health can be greatly affected.
For decades now we have all understood that the gut is full of microbes that can both help and potentially hurt us (e.g. Acidophilus is good; C. difficile is bad). Many people have found relief for illnesses like Irritable Bowel Syndrome in the form of a probiotic capsule. But this book shows us that microbes affect all parts of our bodies, not just the gut.
The authors travel, chapter by chapter, through the human body discussing how microbes help create health and disease. The first fact that jumped out at me was that there are as many bacterial cells in the body as human cells. Think about that for a second. Half of the cells that help us live, and that are in and on our bodies, are bacterial. How can that many active cells be with us and not affect our health?
All parts of the body are in touch with microbes—even the deepest parts of our lungs (a place only recently believed to be bacteria free). From the brain to the heart and lungs, from the digestive system to the skeleton, muscles, and skin, studies on all areas are summarized here. Illnesses and disorders as varied as obesity, inflammation, multiple sclerosis, kidney stones, autoimmune diseases, and cancer are discussed with regard to the microbiome.
Having a 15-year-old son at home, I was quite struck by the discussion in The Whole-Body Microbiome about how Cutibacterium acnes on the skin helps to fight acne.
And having a life-long obsession with oral health, I found it good reinforcement to read that because of oral bacteria, “individuals who do not brush their teeth daily have a 22 to 65 percent greater risk of developing dementia than those who brush their teeth three times a day!”
Our understanding of how certain interactions occur is changing with new research, for example into the links between cardiovascular disease (CVD) and red meat. It’s not the meat or the fat (and certainly not the cholesterol in the meat) so much as the microbes in the meat that seem to be the culprit:
When you eat red meat, the microbiota in the meat itself convert components of meat into specific compounds… the liver then converts these compounds into a derivative compound … which then causes plaque accumulation and CVD. Without red meat and its accompanying microbes, these compounds are not made, which drastically reduces the incidence of CVD and stroke.
With new information like this, our approach to health will certainly be changing drastically over the coming decades.
Since this is a relatively new field of study, a lot of the information in this book is preliminary. Most of the studies referenced have been done on mice or small numbers of people, but the preliminary results point to the need for further research and suggest changes that can make a difference in your health.
The main changes the authors recommend might sound familiar:
• Establish and maintain a healthy diet — yo-yo dieting does not work, partly because the microbiome has a memory and tries to get you back to your former stasis.
• Do your research before committing to a probiotic— there are some good ones for certain conditions, but there are a lot of useless products out there as well. Keep an eye out in the future for better probiotics.
• Consume different kinds of fibre (prebiotics).
• Don’t take antibiotics unless you need to — get medical tests to make sure you have a bacterial infection that could benefit from the right antibiotic. Also, use probiotics, prebiotics, and diet to help.
The Whole Body Microbiome is a revealing and interesting read, written for the general public and accessible to all. This up-and-coming scientific discipline of microbe management could help us all in the future. Let’s just hope it doesn’t unleash some mysterious and undesirable Kraken!
Sandi Ratch is a writer and heritage consultant with a masters degree in Archaeology from Simon Fraser University.
***
The Microbiome Master Key: Harness Your Microbes to Unlock Whole-Body Health and Lifelong Vitality
by B. Brett Finlay & Jessica M. Finlay (D&M $26.95)
Review by Graham Chandler (BCBW 2026)
I n 2017, B. Brett Finlay co-authored Let Them Eat Dirt: How Microbes Can Make Your Child Healthier (Greystone), a book that cautioned parents not to create hermetically sealed cocoons for their young children, “because early exposure to a wide variety of microbes is key to firing up the immune system,” he wrote.
The field is still extremely new and Finlay’s latest title, The Microbiome Master Key, co-authored with his daughter, Jessica M. Finlay, covers the latest findings about the role microbes play in all phases of our lives, starting with birth. “The moment you’re born, you receive your very first and very best birthday present: a big dose of vaginal and fecal microbes,” say the authors.
There is some surprising information about everyday life routines such as eating and drinking. For example, while drinking alcohol in excess is unhealthy, moderate consumption of red wine has been associated with health benefits including protection from cardiovascular disease and type 2 diabetes. Red wine is a component of the Mediterranean and MIND diets, both of which lessen the risk of neurological diseases such as dementia, the authors point out. Also stressed is the importance of regular exercise.
It was interesting to learn that microbes play a role in susceptibility to Parkinson’s disease, the second most common neurodegenerative disease after Alzheimer’s. Parkinson’s affects 3 to 5 percent of over-85s and is thought to start 20 to 30 years earlier in the gut. (Historically it was thought that the gut could be a source of reasoning, hence the common expressions “gut feeling” and “go with your gut”.) Most common clues to Parkinson’s are constipation and loss of sense of smell—both of which hint at microbe involvement. In fact, much of the research data point to Parkinson’s disease being associated with gut microbes before brain symptoms are noticed—a paradigm shift in thinking about the disease, say the authors. Moreover, microbes associated with the MIND diet are thought to significantly delay onset of the disease; additional studies are underway to see if and how this is associated with microbes.
“There is one number that predicts your health and life expectancy more than any other: your postal code,” the Finlays write, adding that it’s a myth longevity is determined by genetic factors. Instead, they maintain that the everyday social and physical conditions of life—where you live, who you interact with, what you eat, how often you exercise—can influence health and longevity to a much greater extent (about 75 percent in studies) than genes (about 25 percent).
The role played by microbes is unavoidable. “Every time you open the front door, a gust of air carries microbes into your home—as do dogs, visitors, Amazon packages, and your own body, which picked up microbes from your car, the sidewalk, your office etc. These microbes are critical, as Americans now spend about 90 percent of their time indoors,” say the Finlays. “This goes against human nature. We did not evolve in sterile chambers or closed rooms, but rather in contact with nature. We slept on cave floors, had limited hygiene rituals, and spent most of our time outside with other people and animals.”
“We may be more productive, connected, and technologically advanced compared to our ancestors, but we’ve also alienated ourselves from many of the essential microbes that evolved with us,” they go on to say. “This shift to the sterilized indoors has had some unintended consequences.” They illustrate with an example: “Children who grew up on Bavarian or Amish farms, and in close proximity to livestock had significantly lower prevalence of some allergies.”
One place where there are probably too many microbes is on our cell phones. The new research on cell phones is surprising: they are far dirtier than we might ever have expected. “They are actually vast reservoirs for bacteria—the more microbes they collect, the more microbes wind up on our hands, face, and everywhere in between…one study showed that Americans check their phones on average 144 times per day, which provides plenty of opportunities for microbes to move from our fingers and palms to our phones.” University of Arizona researchers have found that cell phones carry ten times more bacteria than most toilet seats. Yet, ironically, unlike the bathroom, people rarely clean or disinfect their phones.
There’s lots more. This volume is chock-full of results of new and fascinating research; all written and presented in easy-to-understand prose. Sidebars supplement the text where needed—many to clear up “myth versus fact.” Extensive references are presented as well as useful “Key Tips” at the end of each chapter. Read it. It could change—or possibly save—your life. 9781771624428
Graham Chandler is a Vancouver-based freelance writer.
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