Not to freak you out, but right now there are tens of trillions of invisible organisms all over you. They’re moving up and down your face, backstroking in your stomach, just having a grand old time. In fact, there are as many of these organisms as there are cells in your body. This means that, if you really think about it, you’re divided into one of two parts: a human one and a bacterial one.
“Many people think of microbes as germs, and (that) we need to get rid of (them) because they cause disease,” says Ed Yong the author of the fascinating new book I Contain Multitudes: The Microbes Within Us and a Grander View of Life. “But in fact the vast majority are benign or beneficial to us. And they do incredible things.”
In Multitudes, Yong, a TED-talker and regular contributor to The Atlantic, makes it clear that the study of microbes is the study of us, and that this is one of the most fascinating and important areas of research today. We spoke to Yong about his book, and found nine pieces of information you should know about the invisible world.
1. The Microscopic Creatures Are More Than Just Hitchhikers
Each and every one of us is a thriving community of microbes. “Every human has tens of trillions of them in our bodies, and at least one microbe cell for every one of our human cells,” says Yong. “And the same is true for every animal, so whether you’re talking about an elephant or an ant.” These organisms, per Yong, are not just hitchhikers and passengers. “They actually play a profound role in our lives and in the lives of nearly every living creature,” he says.
2. And We Are Entirely Dependent on Them
“We think that when we grow from a single egg into a fully fledged adult, we do so under our own steed, under the instructions encoded within our own genome,” says Yong. “And yet it’s clear that microbes also shape the development of our own organs.” He goes on to say that, while we think that our minds are the product of our own free will, we know that thanks to rodent-based studies, microbes also shape our mood and anxiety levels. “We are definitely more dependent on microbes than we realize,” says Yong.
3. There’s No Such Thing as a Good (or Bad) Microbe
We live in symbiosis with all our microbes, which means the relationship isn’t negative or positive. “It could go either way and in fact it often does,” says Yong. For example, the bacteria in our guts are really useful for digesting our food or training our immune systems. But if they get into the wrong place and, say, cross the lining of the gut and enter the bloodstream, they can really harm us. “There’s always a bit of tension between us and the microbes,” says Yong. “The relationship is always at risk of breaking.”
4. We Can Change Our Microbial Makeup By What We Eat
The food we consume is one of the main drivers of the microbes that live within us. Eat poorly and you’ll face the consequences, eat well and the bacteria will help you. According to Yong, dietary fiber is one of the best things to be sure to eat, as it nourishes a wide range of microbes in the gut. “So if you eat a wide range of plant food and fiber, you can nourish a more diverse microbiome,” says Yong. “In return, the microbes in our gut convert fiber into substances that are helpful to us, that reduce inflammation, and to sure up the lining of the gut and to actually feed gut cells.”
5. Even So, All Those Books Preaching the Perfect Gut Diet Are Bullshit
Telling people to eat dietary fiber is a no-brainer. Prescribing a diet based on the gut? Not really doable. “It’s really hard to prescribe any particular good-for-the-gut diet,” says Yong. “And in general, as in a lot of nutrition science, the more specific the recommendation becomes, the less likely they are to actually be true.”
6. Probiotics Mostly Are, Too.
Many people preach the gospel of probiotics — the bacteria-feeding substances found in yogurt. But Yong says that while they’re good for certain conditions like infectious diarrhea, they don’t actually live up to their myriad health claims. “The evidence that we have at the moment suggests that they don't actually have much of an affect as they contain only a small number of microbes including species that aren’t particularly good at colonizing the gut,” he says.
7. We Shower Too Much
Soaping up our hands, scrubbing the floors, and taking an antibiotic are all fine in moderation, but per Yong, the evidence suggests that we’re killing too many good bacteria by being overly sanitary. ”Exposure to microbes is important to building and tuning our immune systems, and a lack of that exposure might explain why many of us have grown up with very twitchy, overactive immune systems,” he says. “Think of the immune system as a thermostat. We have messed with the dial by reducing our contact with the microbes that calibrate it.”
8. Microbes Enable A Certain Type of Squid to Be Invisible
It’s called the Hawaiian bobtail squid and it lives in the Pacific. The bobtail squid has a particular glowing bacteria in their bodies called biblio fisher that matches the moonlight shining down from above. “This means that any predator looking up at the animal can’t see it because the bacteria is counter-illuminating it,” says Yong. The more amazing thing is that out of all the thousands of bacteria in the bobtail’s environment, biblio fisher is the only bacteria with which it forms a partnership. “I think that just testifies to how profoundly a microbe can shape an animal’s body and the course of its life.”
9. Scientists Are Using Microbes to Fight Zika and Other Diseases
There’s a microbe called wolbachia, which is a bacterium found in a lot of insects, infecting around 40 percent. (Side note: It’s not very friendly toward males, and is rather good at decimating the male population of certain insects.) When put into a mosquito, a host to which it is foreign, wolbachia, stops the mosquito from spreading the viruses behind Dengue Fever, Malaria, Zika, and other such horrible diseases. “Scientists can spread it through a wild population, rendering all of the mosquitoes in an area incapable of spreading these incredibly important human diseases,” says Yong, who adds that the diseases-free, wolbachia-infected have been released in countries like Brazil, Indonesia, Colombia, and Vietnam, and results are positive. “It’s all just the beginning,” says Yong.