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Do You Know What's Living in Your Shower Head?

Researchers at the University of Colorado are studying the ecosystem of microbes that can live in shower heads. (Joe Amon / The Denver Post)

What’s Really Living in Your Showerhead?

Prepare to feel the need to take a shower — but then think twice before jumping in.

A University of Colorado study is shining a light on the world of tiny creatures living in your shower head.

“Microbes are everywhere you look,” said Noah Fierer, associate professor of Ecology and Evolutionary Biology and a fellow in the CU Cooperative Institute for Research and Environmental Sciences. “There’s an ecosystem inside your shower head; it just happens to be man-made.”

Fierer is studying the microbes that live in homes, from the cutting board to the toilet.

He and research associate Matt Gebert have found the shower heard, with its moisture and warm water, is a perfect breeding ground for “a dynamic community of specialized bacterial species.”

These bacteria have the power to influence human health.

Those whose immune systems are already compromised could be susceptible to illness from the innards of their shower head, but others can thank the microbes as they also can strengthen the immune system and increase resistance to disease.

To continue their studies, Fierer and his group are tapping into citizen science, sending 1,500 sampling kits to households in 49 U.S. states, Puerto Rico and parts of Europe. Citizens are filling out information about their shower heads and giving the inside of their shower heads a good swab.

“After unscrewing the face of the shower head, each participant carefully ran a sterile swab along the interior, scooping up the delicate layer of microbial biofilm clinging to the metal’s surface,” read a post from the research institute.

The gunk, which researchers referred to as “shower slime,” is then anonymously mailed back to CU for testing.

The researchers assure the slime samples are pouring in.

“Not only does this research have the potential to influence the medical community, but it also gives microbiologists a better understanding of the wide variety of microbial niches in homes across the world,” the post read. “The more we humans change our surroundings, like changing the chemistry of our tap water, the more we are changing the types of microorganisms we interact with.”

Elizabeth Hernandez: 303-473-1106,,