Some of the most diverse environments in the world can be found right in our bathrooms—virally speaking. Scientists swabbed people’s toothbrushes and showerheads and found them brimming with hundreds of different viruses, many of which have never been discovered until now. Thankfully, though, these bacteria-hunting viruses aren’t dangerous to people.
The world is filled with countless viruses, bacteria, and other microscopical life. While the vast majority of these microbes pose no threat to humans, many can provide us important lessons about their surroundings and some might even have practical applications, such as showing us new ways to fend off bad germs. So scientists are always interested in cataloging previously unknown microbial neighborhoods, also called microbiomes.
“Toothbrushes and showerheads harbor phage that are unlike anything we’ve seen before.”
Researchers at Northwestern led this new study, published Wednesday in the journal Frontiers in Microbiomes. The research is an extension of their previous project, nicknamed Operation Pottymouth. The scientists intially wanted to study unexplored bacterial microbiomes close to home.
“There is so much about the world around us that we don’t understand—including the things that may seem familiar. We started out looking at things like toothbrushes and showerheads because they are important sources of microbes that we’re exposed to, but we don’t know which microbes they carry or what factors influence them. Our original studies identified a bunch of bacteria, which is in and of itself super interesting,” lead researcher Erica Hartmann, a microbiologist and associate professor of civil and environmental engineering at Northwestern’s McCormick School of Engineering, told Gizmodo. “But the ‘next frontier’ of microbiology is phage. There are so many phage out there, and we know so little about them. So we decided to start just by looking at what’s around us.”
This time, Hartmann and her team analyzed the viruses living inside our toothbrush and showerhead bacteria, a group of viruses known as bacteriophages. They unearthed an immense amount of phage in their samples, tallying over 600 viruses in total. There were no clear patterns among the viruses they found, but phage that infect mycobacteria did tend to be a bit more common. Some mycobacteria are known to cause serious diseases in humans, such as leprosy and tuberculosis.
“Toothbrushes and showerheads harbor phage that are unlike anything we’ve seen before. Not only did we find different phage on toothbrushes and showerheads, we found different phage on each toothbrush and each showerhead,” Hartmann said. “This amount of diversity is huge, and it isn’t because of anything specific to toothbrushes or showerheads. There are just so many phage out there waiting to be discovered.”
Bacteriophages are, as their name suggests, a problem for bacteria, not people. But we’ve started to study and deploy phages as treatments for our bacterial infections, particularly bacteria that have evolved to resist antibiotics. So it’s certainly possible that scientists like Hartmann will be able to discover something medically useful from the phage or other microbes that her team has discovered in our bathrooms. But even the discovery alone is worthwhile, she adds.
“It could be that the next great antibiotic will be based on something that grew on your toothbrush. Even if this doesn’t lead to some great new technology, it’s important to observe and record the diversity of phage because it expands our fundamental understanding of biology,” she says.
Given how little we know about phage and other microbes, the researchers plan to continue sampling all sorts of environments—both familiar and exotic—to further map out their worlds. They’re also developing new methods to better observe them and how they work. “This will give us a fuller picture of what types of microbes we all encounter in our everyday lives and potentially lead to new discoveries and inventions to better protect human and environmental health,” Hartmann said.
