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Good Germs, Bad Germs: Health and Survival in a Bacterial World

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Good Germs, Bad Germs: Health and Survival in a Bacterial World by Jessica Snyder Sachs, is an up-to-date summary of what we know about how bacteria interact with humans.

It's a fascinating story, because after a lifetime of "fighting germs" it seems that scientists are coming to learn that the interaction between bacteria and our bodies is far more complex than was ever realized and we have to work with germs and make alliances with "good germs" in order to survive.

The book starts out with several chapters that explore in greater detail than I've seen elsewhere, the research that has been establishing "The Hygiene Hypothesis." This is the idea that the huge rise in autoimmune disease we are currently experiencing is being caused by too much cleanliness.

It is starting to look like we are not being exposed to enough of the right bacteria very early in life or as we go through our daily lives, thanks to changes in water treatment, how we get our food, how we medicate illness, and how we clean our homes.

It turns out that our bodies are complex ecosystems in which maintaining populations of billions of bacteria of various kinds is essential for preserving our health, particularly in the digestive system, where, if our population of bacteria are killed off, the digestive system fails to function properly. Children absorb the good bacteria they need to have populating their own digestive tract from birth on. A caesarian birth, for example, results in a baby who is not exposed to the bacteria found in the mother's perineal area, which raises the risk of developing autoimmune problems like asthma and Type 1 diabetes.

Children who are given antibiotics early in life which kill off the developing populations of healthful bacteria also develop more autoimmune diseases, particularly asthma.

And all of us who drink filtered water (which the book mentions was not common until the last 25 years of the 20th century) and eat packaged, preservative-filled foods, may not be maintaining the colonies of soil and fecal bacteria which our bodies depend on to regulate our immune systems and fend off dangerous bacterial invaders.

An important point that Sach's raises in Good Germs, Bad Germs, is that while in the past many people, including those opposed to vaccination, have argued that exposure to disease is required for the development of a healthy immune systems this is not, in fact, true. More recent research suggests that it is not infection with disease that protects children. Disease, is NOT good for people.

What is good for people is acquiring populations of benign non-disease causing bacteria that live on skin, on mucous membranes, and within the digestive tract. This is because these populations of benign bacteria do two things. One is that they fill up the ecological niche your body represents, making no room for the more dangerous bacteria which cause disease to move in.

The other, which is just starting to be understood, is that by their very presence, these benign bacteria send out biochemical signals that cause the immune system to respond by developing what is called "tolerance"--i.e. turning down the immune system. It is this tolerance that turns off the inappropriate immune attacks that cause asthma, diabetes, multiple sclerosis, etc. When the body is not populated by the bacteria it expects to meet, it does not develop tolerance, and instead seems to go on high alert, and unfortunately, this leads it to attack things like peanuts and pancreases.

Another interesting finding is that having the right bacteria established in your body causes changes in the cytokine mix which affect your mood. Sachs describes some research that finds that when levels of Interleukin-10, a cytokine that is secreted when tolerance develops, rise, serotonin levels surge too. The implication here is that the depression that is associated with autoimmune disease may not be psychological. Yes, it is a bummer having to deal with diabetes, but it may FEEL like a bummer because of the lack of calming chemicals in the brain.

This reminded me of one of the oddities of tuberculosis in the 19th century, which is that its victims were always described as being bizarrely cheerful especially as their condition worsened. One wonders if perhaps this had something to do with their immune systems having developed too much tolerance and pumping out serotonin happy juice. The book mentions that this kind of inappropriate tolerance can develop in the presence of some kinds of chronic infections that the immune system cannot take care of.

The good news reported in this book is that there are people working on using carefully cultured populations of benign bacteria to modulate the immune system. The bad news is that it turns out that bacteria can trade just about any trait you can think of with each other, particularly resistance to any antibiotic ever made, and they do it across species lines and very, very fast. A bad bug you pick up on your spinach can pick up a drug resistance gene from a "good" bacteria in your gut in the 3 hours it takes to hit your lower intestine.

This means that the most "healthful" bacteria in the world can go bad if you already have drug resistant bacteria haunting your gut. And unfortunately, most of us do. Much of the rest of the book is taken up with discussing the problems caused by the drug resistant bacteria that now fill our world.

One huge reason for the unstoppable growth of MRSA and other bacteria that do not respond to antibiotics is the overuse of antibiotics in animal feed. It turns out that the problem is not just residues that you might eat. The problem is that resistance genes that develop in livestock pass into the ground and get out into the world where the promiscuous bacteria trade them around continually. You don't need to eat meat to get bacteria in your gut that are resistant to antibiotics used only in cattle.

Another problem is the use of antibacterial soaps which kill off the friendly bacteria in our homes and leave a nice, big empty place for baddies to grow. Sachs compares cleaning your cutting board with antibiotic soap to nuking your lawn with Roundup without reseeding it, which ensures that you will end up ONLY with clumps of crabgrass and weeds.

There's lots more in this book that you should read if you are concerned about MRSA or worry about infection. And if you aren't concerned about MRSA, you should be!

I've read a number of books on microbes in recent years, including

Bakalar, Nicholas. Where the Germs Are: A Scientific Safari (2003)
Biddle, Wayne. A Field Guide to Germs, 2nd ed. (1995, 2002)
Ewald, Paul W. Plague Time: How Stealth Infections Cause Cancers, Heart Disease, and other Deadly Ailments (2000)
Heritage, J., and E. G. V. Evans, R. A. Killington Microbiology in Action (1999)
Karlen, Arno. Biography of a Germ (2000)
Murray, Patrick R., et al. Medical Microbiology (2002)
Oldstone, Michael B. Viruses, Plagues, and History (1998)
Shnayerson, Michael and Mark J. Plotkin. The Killers Within: The Deadly Rise of Drug-Resistant Bacteria (2002)
Tierno, Philip M. Jr. The Secret Life of Germs: Observations and Lessons from a Microbe Hunter (2001)

What sets science journalist Jessica Snyder Sachs' book apart from these fine books is the intense detail and focus that she brings to the work and the fact that her book is up to date with reports from the latest research. Written for a general educated readership, it gets a little dense at times and there's a lot to keep in mind and to understand. But I think the time and effort are worth it. I must warn you however, it does get a little scary. If you are prone to hypochondria or to paranoia, I would suggest you skip reading this since it appears that we are teetering on the edge of any number of possible microbial disasters.

At the same time there is also the promise of a level of understanding of how drugs, bacteria and our immune systems work together, or are at odds, that will lead to healthier lives for all of us.

Some of the topics covered:

--A bit of the history of medicine before the germ theory of disease rose with Pasteur to the balmy times circa 1960 when some authorities were predicting the end of infectious disease, to the rise of antibiotic resistant bacteria that characterizes today's world.

--The interaction between bacteria in our intestinal tract and the fact that we could not digest our food or even live without the benign bacteria that help us. Sachs quotes Nobel laureate Joshua Lederberg in this regard: "'It would broaden our horizons if we started thinking of a human as more than a single organism. It is a superorganism that includes much more than our human cells.' Lederberg calls this cohabitation of human and microbial cells the 'microbiome...'" (p. 238)

--The "hygiene hypothesis," in which certain diseases such as allergies, asthma and immune system disorders are thought to arise because we keep our homes too clean, and our children do not have the exposure to common germs early and often enough to build up a proper immune response. In the case of allergies and autoimmune diseases, apparently exposure when very young to would-be allergens "teaches" the immune system to regard them as harmless. Without this exposure the immune system may go wild. Sachs' treatment of this murky subject is the best I have read.

--Bacterial mutations, including the exchange of drug resistant genes between species within our intestinal tract. (Bacteria do have sex on occasion!) This rather sobering part of the book explains how bacteria manage to elude our best defenses and prescriptions. Implicit is the fact that we do indeed live in a bacterial world that has in toto a greater grasp of biochemistry than perhaps we will ever have. They've had two or three billion years to perfect their defenses, so we have our work cut out for us.

--Various new methods of dealing with microbes including new drugs, infecting bacteria with viruses, inculcating ourselves with good bacteria to keep the bad out, bioengineering new benign strains to replace the dangerous ones. This approach is called "probiotic," that is, "proactively replacing the body's trouble-prone bacteria with strains and species of our choosing, even of our own making." (p. 193)

--Enhancing the immune system so that it better fights harmful microbes while at the same time leaving its own tissues alone, checking inflammation and autoimmune disease.

Some interesting info:

Our intestine when empty of food harbors about 15 trillion microbes; when full, perhaps 100 trillion! (p. 44)

Babies typically get their first intestinal bacteria by riding face down out of the womb, picking up a bit of the inhabitants of mother's stool. (p. 53) Babies delivered by caesarian section have more allergies than vaginal birth babies and may have a tougher time setting up a stable flora in their digestive systems. (pp. 99-100)

It is now clear that healthy tissues in our bodies are not necessarily microbe-free. In fact, I learned here that the way the immune system works sometimes is to ignore resident bacteria that are not causing any trouble. Furthermore, our immune systems can get used to some pathogens and just leave them alone after awhile. In fact sometimes real trouble starts when the immune system goes into high gear and tries to rid the body of every last germ. A case in point is the plaque build up in the arteries of some people in reaction to the presence of harmless bacteria. In other people the immune system doesn't respond and there is no plaque build up leading to heart attacks.

The fact that "it's not bacteria that wreak the deadly damage of sepsis, at least not directly." Instead, it is "a person's own immune system...." (p. 221)

This is an outstanding book, engagingly written, meticulously edited and proofed, with a plethora of endnotes and an excellent index.

This book is extraordinarily well-researched, well-balanced and well-written. I co-direct a graduate level course on biopharmaceutical innovation and will use this book for the class. However, it is fully accessible at the high school level, and should probably be read then, since the topic is so important, and misunderstandings so widespread.

Starting at birth, the new, innocent body becomes home to a host of microscopic invaders. These days, at that same instant, forces are brought to bear to stop or repel that horde. As Jessica Sachs explains in this comprehensive account, we are only learning the first lessons in what microbes mean in our lives.

Perhaps the first thing readers should take from this book is that "antibiotics" don't contend with viruses. Those costly drugs only fight bacteria, a more complex and elusive critter. Another difference between bacteria and viruses is that we generally need the former, but not the latter. Which means we'd best be cautious about trying to ravage them with chemicals. The number and variations of bacteria in our bodies seems countless as you follow Sachs' account of who they are and what they do. Or fail to do. Most of us grew up with the "bad germs" litany drummed into us. "Wash your hands before dinner!" and "Don't play in the mud!" still echo in our minds after many years. The point was to "prevent" germs from entering our bodies. It turns out that Mum's cautions weren't always on the mark - Mummy didn't know best after all. We needed those bugs - they help us stay healthy.

Jessica Sachs guides us through the findings of scores of scientists' work that has revised the approach we were taught about "germs" in our childhood. Eating mud, something many of us were at least verbally chastised for, turns out to be a good thing, even a necessity. From birth, the introduction of certain microbes initiate processes the body needs to keep going. For most people today, it's well known that microbes in our tummies are part of the process of digestion. Escherichia coli is known to be a true friend - in controlled numbers and certain strains. What's less known is how many other bacteria the body relies on to get certain jobs done. One of those jobs is keeping the immune system properly tuned. A lazy immune system is unresponsive or unable to react to invasion. An overly ambitious one can turn on its own body and destroy it.

Both friendly and destructive bacteria live in our mouths, eyes, skin and elsewhere. Over millions of years, the body has come to an accommodation with those creatures, generally striking a balance ensuring survival. This balance has been severely offset in recent years, due to a "cleanliness" obsession that arose when it became clear that some germs were responsible for diseases. This idea was effectively demonstrated by UK researcher David Strachan, whose research led to what is now called the "hygiene hypothesis" - respiratory illnesses result from lack of cross-microbe activity to build immunities. In short, rich, small families were more prone to allergies than large, poorer ones. As Sachs points out, humans in our society overreacted to the new knowledge about disease-causing germs and sought to eliminate them all. The imbalance has led to many tragic situations, and initiated a guarantee that more, perhaps worse, situations are in the offing. What are we to do about it?

At the end of a superb compendium of case histories, research investigations and depictions of the scientists themselves, Sachs arrives at glancing into the future. The path is vague and unclear, chiefly because we have changed the past so drastically in our present - particularly in North America. European research has offered some pointers, but the microbe population here has already been distorted beyond restoration to past conditions. This situation indicates drastic new approaches must be tried. Perhaps the most disturbing for many will be the development of bio-engineered treatments. The realisation that bacteria can not only pass antibiotic-resistant genes among their kin, but provide them to other species means "scatter-gun" forms of vaccines must be developed. We will likely have to imitate Nature, applying the gene transfer process to counter what human-produced "superbugs" are doing to us. Clearly, the suffering public must be kept fully informed about the options and their implications. The education process begins with this book. [stephen a. haines - Ottawa, Canada]

The author uses her considerable journalistic and literary talents, in this remarkably sourced and current book, to make sense of our bacterial world. It's a world somewhat out of kilter. News coverage of MRSA, allergies and asthma reaching epidemic proportions, and unexpectedly toxic produce and meats, attests to that. But there is also positive news linking bacteria to good health, even a sound heart, head and waistline. In short order, Jessica Snyder Sachs pulls together many and until now seemingly unrelated stories and issues of epidemiology, microbiology and immunology to explain human-microbial symbiosis, eons in the making. The stories include fall-out from our ignorance and disregard of the essential roles played by bacteria, as well as new and positive directions in research to re-establish our healthy co-existence with microbes. The science, lessons, and research, all fascinatingly chronicled in Good Germs, Bad Germs, make for interesting and informative reading. For me, a moderately health-conscious former medical professional, it was full of counterintuitive discovery. I think it would be a worthy read for those interested in personal health, for science historians, and for anyone needing or wanting to understand our necessary life with bugs, the prokaryotic kind.

I purchased this book because I heard an interview with the author on a Scientific American podcast and was intrigued. I've known a few people who contracted MRSA not too long ago and so I was interested in learning more about the topic. When I read the book, it did not disappoint and I found myself not wanting to put it down.

The book covers a number of topics that have been puzzling us recently: Where are these super-aggressive MRSA infections coming from and how did they become resistant to antibiotics? Why are so many children developing extreme allergies to certain foods? The answers are more complex that I originally thought and many go against conventionally held beliefs regarding germs.

Many people I know have the impression that all germs are bad and therefore we should eliminate them through the use of antibacterial agents (soaps, disinfectants, etc). However, research shows that we need these "microflora" as much as they need us and we would be unable to survive without them. There are, in fact, "good germs" and "bad germs" and in our quest to eliminate all germs, we often wipe out those who keep the bad guys at bay.

The book begins with a history of what we know about bacteria and how we've tried to combat disease. The next section presents the idea that we are, in fact, an ecosystem for millions of bacteria. The author explains how we become colonized with microflora from birth and beyond. The main parts of the book explain why our sanitation methods and over-use of broad-spectrum antibiotics may be causing us more harm than good and how we can change our methods to be more successful at combating the bad bacteria.

I found the information in the book entirely fascinating. I had no idea that two distinctly different bacteria could swap their antibiotic-resistant genes so that a bacteria strain that had never been exposed to a certain antibiotic could suddenly become immune to it. Also interesting is that children who grow up exposed to animals (through farm-life or pets) are less likely to develop serious allergies or auto-immune diseases such as Type-II diabetes.

The book provides a wealth on information from hundreds of studies to help the reader understand what we know about germs, how they work, and how they can outsmart us. I walked away with a completely different perspective on germs and their role in our lives. This is a book that everyone should read!

Lastly, I should mention that the author did an excellent job of presenting factual information gathered from hundreds of studies in a manner that was very interesting rather than dull. Also, I don't think a reader has to have a medical background to gain insight from this text.

Jessica Sachs' "Good Germs, Bad Germs" provides an excellent overview of why most of us need to change our views about germs. While its true that impressive reductions in death rates have come from improved cleanliness (eg. Florence Nightingale treating 1850s wounded in Turkey, New York City's street-cleaning, garbage collection, and sewer system improvements in the late 1890s), and killing germs (eg. the development and manufacture of penicillin in the 1930s), not all germs are bad. In fact, severe sickliness and illness can result from nearly or totally germ-free conditions - unusually thin intestinal lining creating a need for extra vitamins, amino acids and calories normally supplied by intestinal bacteria, and unusual vulnerability to naturally occurring toxins in food and other sources.

Improved water sanitation and antibiotics may be responsible for large drops in h. pylori bacteria and associated gastric ulcers and stomach cancer, but they also seem linked to increased rates of acid reflux. Children exposed to microbes from other children, animals and dirty water have less allergies and asthma. Some microbes are associated with improved cheerfulness. There has even limited success treating some cancers with bacteria in England, while a 1958 outbreak of drug-resistant bacteria in newborns was stopped through a harmless strain of staph carried by a nurse whose babies did well.

Today's well-known bad news is that harmful bacteria are rapidly becoming drug-resistant through gene-swapping. Some household cleaning products (eg. pine oil) and compounds in eye drops, nasal sprays, and cosmetics are also guilty. Unstoppable bacterial infections kill over 14,000 Americans each year.

Meanwhile U.S. livestock consume over 10,000 tons of antibiotics/year (vs. 1,500 tons in human medicine) to achieve 50% faster growth. Though about half are not used in human medicine, 2003 monitoring showed Cipro resistant bacteria contaminating about 15% of chicken and eggs on supermarket shelves. (The FDA then banned livestock use of the offending drug; European countries, however, ban most livestock use.)

Hopeful signs include faster diagnoses and bacteria identification (reduces need for broad-spectrum drugs and their impact on benign bacteria and over-stimulation of drug-resistance), research on use of viruses that eat bad bacteria, and utilizing non-harmful bacteria to "take over the field" in those prone to strep throat, ear infections, colitis, UTI, etc. and create difficult, crowded conditions for bad germs.

I won't go into all the details of the book since the other reviews describe it very well. All I have to say is that I was a bit hesitant to purchase it at first since I was afraid it wood be too dry of a read. I recently purchased another science/health relatad book and it was a terrible read.
I'm about halfway done and find myself not being able to put it down. A friend of mine even commented that a book about germs could not be that interesting. Well this one is! It is very well researched and lays out the facts without being (in my opinion) alarmist.
I would hope everyone has a chance to read this book. I only wish our media networks would present this information the way Jessica Snyder does.

Jessica Sachs writes about the intimate relationship between people and micro-organisms. Our skin has a 2-deep layer of bacteria, our mouths and gut have trillions of them; they are a constant part of our environment.

We've co-evolved with bacteria, and we need each other. Animals raised in a truly sterile environment, with no bacteria, do not thrive. Good bacteria help with food digestion, produce enzymes so we have better nutrition, and help fight off disease by crowding out disease-causing bacteria.

It looks as if we've been too successful in sterilizing our environment. Children raised on farms, where they are exposed to more bacteria while they are growing up, have a much lower rate of allergies and auto-immune diseases than children raised in cities. It looks like we need a certain amount of stimulation of our immune system by outside bacteria for it to develop optimally. Otherwise, our immune system grows up to be on a hair-trigger, ramping up too quickly and aggresively. Kids need to get dirty to grow up healthy :-)

This is an excellent book, with a background on the science of bacteria, how they evolve and respond to our use of antibiotics, how we are now threatened by antibiotic-resistant bacteria, techniques for reducing risks from disease-causing bacteria, a survey of probiotic developments and research, and discussion about where we are headed. Well written and engaging, highly recommended.

This book should convince you of a new paradigm. We do not live in a world of bacteria that are trying to invade and kill us. We live in a self-made environment of bacteria that have a stake in our survival, and that protect us from potentially harmful disease. Our use and overuse of antibiotics is changing our individual bacterial ecosystems for the worse, hence the rise of multiply-drug-resistant microorganisms.

Sachs illustrates all this with entertaining clarity, then goes on to describe how current scientists are taking legions of bacteria, putting them through the equivalent of a bacterial Olympics, and deploying the winners to restore a healthful personal ecosystem that can rid us of certain illnesses.

I am a physician with over thirty years in practice. I read and then reviewed and annotated this book, and am writing a newsletter to my patients about it. I think every person, physician or not, will enjoy and learn from this excellent book.