Forget rainforests and coral reefs. Apparently, if you’re looking for a biodiversity hotspot, all you need to do is take a one-way ticket… to your bathroom to find this impressive jungle. In a new study led by Northwestern University, microbiologists have indeed discovered that shower heads and toothbrushes are teeming with an extremely diverse collection of viruses, most of which have never been studied before. And while that might seem worrying at first, this research says it’s actually more than positive. Find out why.
A wide variety of viruses
You’ve probably heard the urban legend that when there is a toilet in your bathroom, your toothbrushes would inevitably end up covered in feces. Well, this new study published October 9 in the journal Frontiers in Microbiomes is actually a follow-up to research by Erica Hartmann, a professor of microbiology at Northwestern University, who previously found that the vast majority of microbes on your toothbrush actually probably come from your mouth and not flushing the toilet by creating a cloud of aerosol particles.
This first study then aroused the curiosity of researchers. “ We wanted know which microbes live in our homes. If you think about indoor environments, surfaces like tables and walls are really tough for microbes. They prefer environments with water. And where do we find water? In our shower heads and on our toothbrushes », explains Erica Hartmann. Her new research subject quickly became apparent to her.
Shower head and toothbrush viruses under scrutiny
For this new investigation, the team sequenced the DNA from samples taken from these two objects. The researchers then identified 614 different viruses on 92 shower head samples and 34 toothbrush samples in the United States. Even more interesting, none of the samples were identical (each toothbrush and shower head seemed to harbor its own unique community of viruses) and the viruses discovered are largely probably new to science.
« The number of viruses we found is absolutely incredible », the researcher is surprised. “ We have discovered many viruses that we know very little about and many more that we have never seen before. […] It’s amazing how much untapped biodiversity there is all around us. And you don’t even have to go far to find it: it’s right before our eyes. »
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Better news than it seems
Although the idea of viruses on your toothbrush might send shivers down the spines of serious neat freaks, researchers don’t see this discovery as a cause for concern—quite the contrary. “ Germs are everywhere and the vast majority of them will not make us sick », insists Erica Hartmann. Additionally, microbial agents detected on shower heads and toothbrushes are actually mainly bacteriophages (or more simply phages). Harmless to humansthese viruses are known to exclusively infect mycobacteria, a type of bacteria that causes diseases like tuberculosis, leprosy, and some chronic lung infections.
Bacteriophages function in two main ways: either they destroy bacteria by hijacking the bacterial machinery to replicate, or they integrate into the bacterial genome to thereby modify the behavior of the bacteria.
Important implications for health
First of all, with an estimate of around a trillion microbial species on our planet, 99.9% of which remain to be discovered, this type of study appears to be essential to fill the gaps in our knowledge on this topic.
Moreover, ” we could consider taking these mycobacteriophages and using them as a way to clean pathogens from your plumbing system “, says Hartmann who adds that she wanted to study with her team ” all the functions these viruses could have and understand how we could use them. »
Above all, these new viruses could be useful for developing treatments against antibiotic-resistant superbugs. Scientists are already developing phage therapies where viruses could complement or even replace traditional antibiotics while overcoming the defenses of dangerous bacteria. As a reminder, these drug-resistant pathogens kill nearly 1.3 million people worldwide each year and contributed to the deaths of nearly five million others. An estimate recently published in The Lancet further suggests that more than 39 million people will die from antibiotic-resistant infections by 2050. This research is therefore crucial.
Hygiene advice against viruses
Credits: Grigorev_Vladimir/iStock
Erica Hartmann recommends washing shower heads with soap and water or dip them in vinegar to remove calcium deposits. She also suggests regularly replace electric toothbrush heads and conventional toothbrusheswhich would be more than enough to maintain good hygiene. On the other hand, she is quite wary of antimicrobial toothbrushes which, according to her, can lead to the appearance of bacteria resistant to antibiotics.
« Germs are everywhere and the vast majority of them won’t make us sick. The more you attack them with disinfectants, the more likely they are to develop resistance or become harder to treat. We should all just accept them », she concludes.
You can consult the study in detail ici.
