very week brings news of superbugs, rare parasites, and flesh-eating bacteria. As two microbiologists working at a medical school, we know full well that those threats are real and can’t be dismissed. But the bad news unfortunately elbows aside the untold stories of the microbes that pioneered life on Earth and the diverse microbes that continue to support our lives.
For the past three years, we have been photographing traces of the earliest microbes as well as the output of those at work today. We’ve captured thousands of images of microbes in far-flung landscapes and fantastic micro-scales. What we saw compelled us to share the beauty of the microbial world in a book of photographic essays, “Life at the Edge of Sight.” It sends a different message about microbes than what often appears in the headlines: The most fundamental realities of the microbial world are remarkably positive. Here are a few of these positive realities and even parallels to be drawn between humans and microbes.
Around 4 billion years ago, primordial cells began to form in a hot, chemical-rich broth. One credible storyline starts inside erupting geysers in a thermal region on land, similar to present-day Yellowstone National Park. Minerals on geyser walls catalyzed the formation of simple types of fat molecules and spewed them into nearby pools. As the molecules collected and interacted, these pools became hatcheries of microscopic spheres called vesicles. Meanwhile, RNA molecules arose through other chemical reactions and began to self-replicate inside vesicles. Heat fluctuations and turbulence in the environment eventually kick-started a primitive cellular life cycle and these proto-cells began to divide and reproduce. Those were the first microbes; that was the first life on Earth.
Soon after the first traces of life appear in the geological record, there’s fossil evidence of microbial communities. In those communities, microbes cooperated, competed, and evolved ways of communicating with each other. Much later on, from within those microbial ecosystems — and never separate from them — larger multicellular organisms evolved. Including us.
Though we are inexorably linked to the first invisible organisms in an unbroken evolutionary chain, our ancestors had no clue about microbes even as they were helping them. Here’s the story of the making of kombucha, a drink that has become wildly popular.
It begins with someone who once prepared a jug of sweet tea and left it to sit undisturbed. (Some say this happened in ancient China; others say it happened more recently in Russia.) After rediscovering the tea a few weeks later, the forgetful one noticed a thick white layer floating atop the liquid. Feeling adventurous, he or she poured the tea into a cup, leaving the white layer behind, and took a sip. “Mmm!” the experimenter exclaimed. It was a tangy and effervescent.
Little did early kombucha drinkers know they were consuming microbes with every gulp. All they knew was that they could keep remaking the drink and sharing the recipe with others as long as they transferred some of the slimy white layer to the next batch.
Without a microscope, the first people to make the fermented foods and drinks that have been savored for thousands of years around the globe — from cheeses to breads, beers, sakes, and more — had no concept of the microbial communities that made them. In the case of kombucha, the white layer is diverse biofilm ecosystem of yeasts, molds, and bacteria held together by a forest of crisscrossed cellulose fibers. Bacteria that generate acetic acid give kombucha the acidic finish that makes your mouth pucker.
A minority of bad actors
As modern microbiology came to be in the 1800s, pioneers like Robert Koch and Louis Pasteur discovered that microbes were responsible for fermentation around the same time they learned that certain microbes cause deadly diseases. Work on these so-called pathogenic microbes was, and continues to be, a necessary priority. Microbiologists have made great strides in medicine by singling out pathogens and finding ways to kill them. But the work by Koch and Pasteur and others quickly and indiscriminately typecast microbes as germs.
It is easy to understand how that happened. The technologies needed to survey the full diversity and abundance of microbial life had simply not been invented. Now we know that there are up to 1 trillion microbial species on Earth, and only a minute fraction of them cause disease. Nevertheless, much of the fear of microbes lingers in the public consciousness. Imagine if every little boy selling lemonade at a corner stand, every grandmother baking a cake, and every good Samaritan were suddenly placed on the FBI’s most wanted list. Vilifying all microbes for the sake of a few is a mismatch of equal magnitude.
Even the idea of a disease-causing microbe is not as simple as it seems. Take Pseudomonas aeruginosa. This bacterium truly deserves its rank on the microbial most wanted list; it can cause many types of infections, some of them life-threatening. However, many people who come into contact with the microbe aren’t affected by it; most of those harmed by it have an underlying medical condition or a compromised immune system. That means there’s a back and forth with the immune system and it’s this interplay, not just the presence of the microbe, that determines if it will cause disease.
In fact, many bacteria capable of causing infections can and do carry out an honest living in our bodies, in the soil, and elsewhere in the environment. Adding even more nuance, some microbes are harmful or neutral depending on which other microbes are nearby. One species of bacteria might be perfectly civil when it hangs around another species, but the absence of that species brings out the worst in it. That phenomenon is true for Staphylococcus aureus, a species of bacteria that lives in the nasal cavities of some 25 percent of the human population. It is likely kept in check by other nearby bacteria. When it isn’t, it can cause skin and other serious staph infections.
These examples demonstrate that all interactions between microbes and humans are on the spectrum of symbiosis. There are the parasitic “pathogens” that harm humans, “commensal” microbes that live on and inside us without any known positive or negative consequence, and those that benefit us while we mutually benefit them. All of these categories of microbes are symbionts, not just the ones that help us, and one microbial species can shift from one relationship status to another in different times and places.
Makers and maintainers of the biosphere
The microbial world is the foundation upon which all other life rests. The mitochondria that make energy in our cells and the chloroplasts that power photosynthesis in plants got their starts as free-living bacteria. Oceanic cyanobacteria less than a thousandth of a millimeter wide produce much of the oxygen we breathe. Microbes in the soil nourish the roots of plants and transform inert nitrogen gas from the atmosphere into a biologically usable form, playing a key role in the nitrogen cycle and other chemical cycles. Bacteria and fungi actually create soil as they slowly break down plant and animal material, including the leaves in your backyard.
Microbes connect the global food web. Look at your dinner tonight. Whether you are a meat eater, vegetarian, or vegan, there would be no food on your plate without microbes. Let’s say it’s a filet of wild salmon. The salmon came neatly sliced and packaged, but it was once a living part of an ecosystem. As it grew, the fish consumed insects and smaller fish. Those animals ate even smaller ones — crustaceans and other kinds of zooplankton. And the zooplankton, in turn, ate single-celled algae called phytoplankton. Take away those microbes at the bottom of the web and the salmon disappears, too.
Of microbes and humans
Throughout the span of humankind, microbes have enabled societies and posed grave challenges to them. They will do the same in our future. Everyone experiences colds and acute infections, and some will suffer more serious interactions with microbes. But it’s thanks to these invisible organisms that we are alive in the first place and capable of experiencing the best parts of life too.
As we see it, microbial life illustrates an intrinsic duality in nature. Microbes make some of the most delightful things on the planet, like wine and chocolate, and they are capable of unimaginable devastation, like the Black Death. Microbes are social creatures that live in communities shaped by cooperation and competition, and they change their behavior, sometimes for the worse, depending on the company they keep. Sound familiar?
Just as we embrace the goodness in humanity in spite of the terrible few, so too should we strive to balance our negative view of microbial life with these overarching positive messages: Microbes gave us life, and they continue to give us life each and every day.
Scott Chimileski is a research fellow and imaging specialist in the Kolter Lab at Harvard Medical School. Roberto Kolter, who directs that lab, is professor of microbiology and immunobiology and director of the Harvard Microbial Sciences Initiative. They are the authors of “Life at the Edge of Sight: A Photographic Exploration of the Microbial World” (Harvard University Press, September 2017). Images from the book are currently on display in the exhibition “World in a Drop” at the Harvard Museum of Natural History, a precursor to the “Microbial Life” exhibition scheduled to open there in February 2018.
“Don’t touch that! You’ll soil it.” – Carl Fredricksen in Pixar’s Up
A few years ago, I went to a scientific meeting to present my research. When we got to the hotel, we checked in and discovered that our room was on an upper floor. When we boarded the elevator, I stepped on first and felt the social obligation to press the number for our floor. Without thinking twice, I did what I normally do when out in public: I used my elbow to touch the button for our hotel floor. And that’s when it happened: my friend chuckled to himself loud enough for me to actually hear it. When I turned back to see what he was laughing at, he quit chuckling almost immediately. It dawned on me after some reflection that he was actually laughing at me (not with me) for using my elbow to touch the elevator button.
In sharing this story, I want to calm all the germophobes reading this. I step up to the line of germophobia, but take one step back. We need to balance our understanding of the microscopic world because it is an essential part of and critically affects our everyday life. A recent study compared skin germs between humans and apes to better understand just how microbes affect our everyday life and personal hygiene in a genuine (though misguided) effort to further prove common ancestry. But before we can understand how the microbiome is part of God’s original creation and better appreciate His marvelous design (yes, even in our armpits!), we must first define some important terms.
Microbes are the earliest forms of life on earth.1 Biology is difficult enough, but microbiology presents a whole new challenge because it deals with organisms that you can’t even see with the naked eye. To clarify, think of microbiology as biology under a microscope. For us microbiologists, the living world we see without using a microscope is relatively boring compared to the unseen living world at the microscopic level (cf. Colossians 1:16). Bacteria are just one type of organism among many at the microscopic level.2 While diversity of life at the microscopic level is not only bacterial, most scientists generally refer to microbes as bacteria. The importance of referring to microbes with only bacteria in mind is important when describing the microbiome.
The word microbiome comes from the root word microbe. Anytime the letters -ome are added to the end of a word, the meaning of the word changes to mean “all of the” word appearing before it. So the microbiome includes all of the microbes for a given location. While sequencing the human genome was significant, sequencing of the human microbiome could be just as important, since the human body houses 10 bacteria cells for every single human cell. The microbiome is usually measured based on DNA sequencing of the 16S ribosomal subunit to generate what’s called a molecular signature.3 The molecular signature acts like a fingerprint to reveal the bacterial identity.
Microbiome scientists are interested in questions such as “What bacterial species are present? And in what abundance?” Scientists think of microbiomes like a chef might think of food when planning to cater for a party. Chefs need to know both how many guests there are in addition to what type of food they like. At the microbial level, microbiome scientists measure the human microbiome by considering who is there and how many. The current scientific model of the microbiome follows the Baas-Becking hypothesis that “everything is everywhere, but the environment selects.” Therefore, scientists expect a certain degree of microbiome similarity between similar locations. But the contrast is also true: if two environments are different, then the microbiomes will be different. So how is our microbiome designed?
Your Designer Microbiome
Most people are horrified when they learn just how many bacteria live on and in us.4 Oftentimes, people react by actively disinfecting all of their personal things. Many are acutely aware of the bad germs surrounding them when they are sick. If we feel ill, we seek antibiotics. Ironically, we’re also supposed to eat lots of yogurt and take probiotics (good germs) on a regular basis—all in the name of health. We misunderstand health and sickness because we want to have our bacteria and kill them too. If we don’t understand the origin and purpose of bacteria, then we are downplaying God’s design and affecting our overall health. Is there a balance?
From the oceans to the soil to the human body, our planet could not exist without microbes. In Scripture, we learn that God first creates something and then He fills it (based on Genesis 1:2). Everything God made was mature, which means microbes were created in association with all of creation to benefit the earth. Dr. Joe Francis does an excellent job explaining the ubiquity and design of microbes with his concept of the biomatrix. The original “very good” creation must have included microbes because they are essential to life. So God created man with bacteria both inside and outside. We find myriad examples of beneficial bacteria in our intestine, and a growing body of evidence suggests that the bacteria on our skin also benefit and protect us.
Bacteria Are the Only Culture Some People Have
Confession time: one of my pet peeves is when someone gets a paper cut and overly worries that it will get “infected.”5 Truth be told, you were “infected” before, during, and after the paper cut.6 Bacteria that harmlessly live in association with us are called our normal microbiota.7 The normal microbiota of human skin is largely determined by a relatively high salt concentration (in case it’s been a while, try sucking your thumb to figure out just how salty it is).8 Actually, it is a wonderful design feature because the relatively high salt concentration creates an unfavorable environment for many bacteria, preventing major skin diseases. Furthermore, the same glands that produce the relatively high salt concentration also provide bacteria with nutrients. The fact that the same bacteria that can withstand a relatively high salt concentration can also thrive on the nutrients secreted by those same salt-producing glands screams that this skin-microbe symbiosis was designed. At the same time, though, these skin bacteria are also responsible for body odor. While you may not consider your body odor a wonderful design, there are additional points to consider.
In any biology textbook, you can find a chapter explaining how animals regulate their body temperature. When any creature’s temperature is outside acceptable limits, there are mechanisms to bring the temperature within normal limits. Our sweat glands lower our temperature through evaporative cooling, but some creatures lower their temperatures using a different mechanism. For instance, man’s best friend (the dog) does not have sweat glands to mediate evaporative cooling. Instead, when overheated, dogs pant heavily to cool themselves. Among the many things that evolutionists try to use as a similarity between humans and apes, they highlight the fact that we both have hair and sweat glands. But what they don’t tell you is how gloriously different our Creator God made us.
While monkeys and apes have skin glands, it is important to note the difference in the location and type of basic skin glands between humans and apes. There are three basic types of skin glands: apocrine, eccrine, and sebaceous glands. The difference between human skin and ape skin is striking.
The distribution, function and secretion of the different types of human skin glands (sebaceous, apocrine and eccrine) are briefly described. . . . Eccrine glands are the best developed and most abundant glands in humans and are widely distributed over the general body surface. By contrast, in most mammalian groups (including prosimians, monkeys and apes, with the exception of great apes) eccrine glands are limited to the friction surfaces of the hands, feet and tail. Apocrine glands, which play an important role in chemical communication, have a restricted distribution in most mammals including humans. . . . All prosimians, monkeys, and apes have thermal apocrine glands associated with hair follicles. The chimpanzee and the gorilla exhibit a distribution ratio . . . [only slightly different from] . . . monkeys, the gibbon, and orangutan. . . . By contrast, humans mainly possess eccrine and relatively few apocrine glands.9
You should cry “foul” when anyone tries to compare human skin to any monkey or ape skin because the similarities are just too few. Regardless of these major differences, scientists recently decided to analyze the armpit microbiomes from humans, chimpanzees, gorillas, baboons, and rhesus macaques.10 In the article, the authors even admit that “the composition of microbes on human skin might be expected to differ significantly from that of our closest relatives, the non-human primates, for at least three reasons.”11 As creationists (and scientists), we expect to find differences based on empirical science. The Baas-Becking hypothesis previously mentioned says similar microbes are found in environments that are similar. Since the environments in armpits of humans and apes have (1) completely different glands, (2) different chemicals secreted, and (3) different concentrations, then the logical expectation based on empirical science is to find significant differences between the skin microbiome of humans and primates (as well as differences in the armpit microbiomes on other animals, because humans were created uniquely from the rest of creation). The only people committed to expecting strong similarities are Darwinists because (and only because) they are committed to a worldview despite empirical evidence to the contrary. Not too surprisingly, the Darwinists were surprised. What did they find? The armpits between humans and apes have few similarities and carry different bacteria. The assortment and diversity of bacteria found in different microenvironments are not surprising between humans and apes when you acknowledge the unique design of each creature and approach science without the wrong presuppositions. The differences between human microbiomes and ape microbiomes are so unique that mosquitoes detect these differences and prefer feeding from certain creatures (i.e., humans) over others (i.e., everything else).12
Want to tell the difference between human and monkey sweat? So easy, even a mosquito can do it!
If even mosquitoes can tell the difference between the human and ape microbiomes, then how do evolutionists interpret the empirical evidence to fit their worldview? The authors of this microbiome study (along with other evolutionists) claim that the evolution of personal hygiene is the culprit. A recent article proposes that we should only shower once a week because we’re “harming” the environment due to personal hygiene products.13 Furthermore, we are often told that the reason humans groom each other is because of our evolutionary history of apes grooming one another. But when you scientifically examine ape-grooming behavior, the irony is that they actually groom out of fear; it is a dominance behavior.14 And when you scientifically examine any other evolutionary claim, you find yourself trying to work out of an armpit existence. Evolution is foul smelling, dark, and damp because it is logically incoherent. Creationists are not surprised to find differences between human and ape skin microbiomes because we are not committed to a worldview claiming humans and apes share common ancestry. As a result, creation scientists are open-minded to existing differences and can ask more sophisticated questions aimed at understanding the skin microbiome and improving health.
The next time you work out, engage in physical activity, or otherwise find yourself sweating, wipe your brow in praise to our Creator who gave us everything we need in our existence. Don’t sweat the small things in life. Keep a cool head. Even as seemingly gross as the microbiome is in this fallen world, there is no doubt that our loving Creator fashioned it to help us when things get tough.