This article originally appeared on VICE US.
A couple of weeks ago, Mica, a 40-year-old from South Carolina, noticed his body odor was a bit different. It wasn't better or worse, but it was definitely not the same. “It's really hard to explain,” he said.
Mica is quarantined with his wife, 39, and like many people isolating at home, their previously active social life has come to halt. “We have been very strict with the quarantine and social distance because I have an asthma issue,” he said. “We have not been in public since March 15th.”
Ileana, a 33-year-old in Ecuador, has found that after weeks of social distancing, she smells a lot better than she did before. “I used to need to apply deodorant every three hours, otherwise [I] smelled bad,” she said. Now, she doesn't need to. She’s at home isolating with three other people, compared to her usual life at the office with over 40 people.
For those of us able to stay at home during the COVID-19 pandemic, our daily lives have undergone radical shifts. Instead of coming into contact with dozens or hundreds of other people per day during our commutes, jobs, and recreational activities, we're at home with a handful of people at most. We're doing this to limit the spread of an infectious virus, yet our actions could be having consequences on other microbes we share our lives with, like our skin microbiome—and it might be changing the way our bodies smell.
Our skin is teeming with microbial life, and the microbes that live on us are responsible for nearly all of our bodily smells. And, crucially, who we interact with influences our roster of microbes. A study from 2014 found that people and animals that share a living environment also shared their microbial communities, “probably because of skin shedding and hand and foot contamination,” the authors wrote. “When families moved, their microbiological 'aura' followed. If one person left the home even for a few days, their contribution to the [family] microbiome diminished.”
Skin-to-skin contact—something else that's greatly diminished right now, at least with people outside of our individual households—reliably results in microbes being passed back and forth. This was demonstrated in 2013 when scientists swabbed the upper arms of roller derby skaters. Before they slammed their bodies around together in the rink, each team arrived with a distinct microbial fingerprint. “The differences between them were so great that it was possible to tell just from a glance at a player’s skin bacteria which team she was from," Veronique Greenwood wrote in The New Yorker. After the competition, the skaters' skin bacteria become more similar to one another, “blurring the distinctions between the teams."
By shrinking our social worlds, we're decreasing our contact with many microbial "auras" while increasing the interactions with the microbes of our housemates—changing the communities that live upon us, and the smells that they make.
Your exposure to microbes has likely gone way down
Many people are at home with just a few others—roommates, partners, or immediate family. If you swap microbes with a small number of people for weeks on end, you could start to smell like that other person and vice versa, said Rob Dunn, a biologist at North Carolina State University.
There is a genetic component to which microbes thrive on our bodies, said Julie Horvath-Roth, a geneticist who studies microbes at North Carolina Central University and the North Carolina Museum of Natural Sciences. Yet many microbes from another person should be able to live on your skin too, so the microbes you're exposed to every day matter.
“Whoever we’re spending more time with, and whichever species we’re spending more time with, we’ve upped the probability that we’re going to pass back and forth those denizens of our bodies,” Dunn said.
Dunn's lab has also studied the belly button microbiome, and said a similar phenomena could be happening there too: The longer you spend with just a few other people, the more similar the microbes in your belly button will become. Belly buttons are typically home to incredibly diverse microbial life: In their 2011 research, they found 2,368 bacterial species in just 60 belly buttons. Science writer Carl Zimmer, who participated in the study, had one belly button microbe that had “previously been found only in soil from Japan.” Zimmer had never been to Japan.
But if you’re isolated alone without a roommate or partner, you might be facing slight losses in diversity, especially of those more rare microbes. The longer you're by yourself, “the higher the probability that an individual microbe lineage might go extinct,” Dunn said. “If that happens and you're really on your own, you don't have many sources from which another one could recolonize."
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You might be appropriating some of your housemates’ smells
Sophia, a 25-year-old in Portland, Oregon, said she’s been smelling “notably worse” during quarantine.
She’s been socially isolating since early to mid March. “This is significantly different from my previous day to day. Monday to Friday I would typically be in an office of about 50 people and go to the gym or fitness studios every day," she said. Now, she only comes into close contact with her live-in boyfriend who she said (with his agreement) is more smelly than she is.
Our aromas come from the mix of species of microbes that live on us, which can vary a lot person to person. The particularly smelly locale of the armpit hosts apocrine glands, whose only job is to secrete a substance that feeds our underarm bacteria, which then produce compounds that “smell like armpit,” Dunn said.
Getting someone else's armpit microbes has already been shown to alter a person's smell. Chris Callewaert, a microbiologist and body odor specialist at the University of California, San Diego, and Ghent University in Belgium has helped people become less smelly by giving them “armpit transplants.” (Callewaert is also known as Doctor Armpit.)
In one experiment, Callewaert had a stinky identical twin wash under his arms with antibacterial soap for four days, then gave him the bacteria from the armpits of his less-smelly twin brother. After the “transplant,” the smelly twin remained stink-free, even a year later. In a small study, he found that 16 out of 18 people’s B.O. similarly improved after an armpit microbial transfer.
Regardless of whom you're quarantining with, your armpit microbes are also strongly affected by whether or not you use antiperspirant, which limits sweating, or deodorant, which addresses smell only. Using antiperspirant wipes out most of the armpit microbes, and Dunn's lab has found that when people stopped using it, the amount of bacteria in their armpits rebounded.
If people have stopped using these products during quarantine (or are using them less often), it gives microbes a chance to re-colonize. If you’re trapped in an apartment with just one other person, and you're using less antiperspirant or deodorant, Dunn said it’s possible the microbes that recolonize you could come from your quarantine buddy.
“I'm just speculating, but you might imagine that if one person has used antiperspirant for years and the other hasn't, the growth microbes of the person who hadn't would then be the ones that would colonize the person who had [and stopped using it],” he said.
Another factor influencing any new or changed smells may be stress, Horvath-Roth said. When we’re stressed out, the glands in our armpits produce more food for the microbes that live there. “Maybe you are getting more of some of the smelly microbes,” Horvath-Roth said. “But maybe also you have a lot of the same microbes and your body is changing.” (She added that while changes in diet are known to affect the makeup of the gut microbiome, it's still unknown exactly how food affects the microbes living on our skin.)
Finally, the clothing we’re wearing could also be changing our microbes: Studies by Callewaert have found that polyester fabrics tend to hold smellier organisms. “Presumably people are now more in sweat pants or just casual clothes and they're not in their nice silk blazers,” Horvath-Roth said. “Your clothing choice is probably also impacting which microbes are growing on you and staying on you.”
Your changing stink may not be that important, but your skin bacteria is
Smelling your body, and noting how it changes, can serve as a friendly reminder that your skin microbiome is alive and present, probably doing important things for you—even if scientists don't know what those are just yet.
There’s a definite connection between the microbes that live in our gut and human health—an explosion of research over the past two decades has examined how these bugs impact our body and minds. “I think there’s a lot less known about the skin,” Horvath-Roth said.
It takes our bodies a lot of effort to feed all our skin microbes, Dunn said. And since we have special glands dedicated to keeping them alive, evolutionarily speaking, it indicates that the microbes are doing something for us. Still, Dunn said, “We don't have a great understanding of what that is.”
Skin microbes might serve as a first defense against bad bacteria and viruses—the first thing many pathogens encounter is not our immune system, but the layer of microbes on our skin.
Our aromas have been thought to influence who we are attracted to, with some studies suggesting we are drawn to, through smell, people who have different immune systems than us, so that our potential offspring have stronger immune systems. In a study from Russia, women participants rated the smells of men with gonorrhea as worse-smelling than those without, despite not knowing which men had it—indicating that smells could be a clue to many facets of health.
It could be that we've evolved the ability to feed the bacteria on our bodies as a kind of signaling of “who we are (in terms of our identity and relatedness) and how we are (in terms of our health),” Dunn wrote in Scientific American.
Perhaps at one point, our specific smells from microbes helped identify ourselves from others, or one of our own versus someone from an outside group. Gorillas can tell each other apart by aroma, Dunn said. And humans can identify our own smells too: In a study on high school students, most of them could pick out their own scents and that of a friend.
So could a change in our skin microbes, and smells, affect the ways we think about ourselves and others? “Does the boundary between one person and another become more subtle as the aromas begin to change?” Dunn asked.
We don't know for sure, but the good news is that any skin microbiome alterations taking place right now are likely not concerning or dramatic. They might make you smell a little different for a while, but it’s nothing to be worried about. And reclaiming our pre-pandemic smell is just another thing to look forward to when this is over.
“Having lost any microbes, we can gain them back,” Dunn said. “When we reconnect there will be the opportunity to share these microbes anew, and to once again become part of a bigger community of stink.”
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