Public Restroom Bacteria: Not as Scary as You Think?

The moment you step into a public restroom, you likely begin to wonder about the bacteria lurking around. What kind of microorganisms are growing and what risks do they pose to our health? Researchers at San Diego State University set out to uncover the mysteries behind bacteria growing in public restrooms, and the results may surprise you.

Understanding the Bacterial Battleground

The study found that while people do deposit bacteria from both their digestive and genital tracts in restrooms, these bacteria generally don’t survive long. This is because they’re faced with a fierce competition from other, stronger bacteria, such as the ones that can be found on human skin and in outdoor environments.

In essence, public restrooms are a battleground where bacteria continuously fight for survival. And the good news is that the more harmful microbes often lose the battle and die off, making way for safer bacteria to thrive.

Interestingly, the bacteria found in public restrooms are not much different from the ones you’d find in your own home. In other words, you don’t generally have to worry about being exposed to too many harmful pathogens when you use the restroom.

How Scientists Studied Restroom Bacteria

The researchers observed restroom surfaces both hourly and daily throughout a two-month period to analyze the bacterial communities present.

Jack A. Gilbert, one of the researchers, explained their hypothesis and the outcome of the study: “We hypothesized that while enteric (intestinal) bacteria would be dispersed rapidly due to toilet flushing, they would not survive long, as most are not good competitors in cold, dry, oxygen-rich environments. As such, we expected the skin microbes to take over — which is exactly what we found.”

Why Harmful Bacteria Die Off

The potentially dangerous bacteria in restrooms are mostly anaerobic microorganisms. This means that when they’re exposed to air, they become weak and eventually die. When these harmful microbes are killed off, safer bacteria like the ones commonly found on human skin can grow and ultimately overpower and eliminate the pathogens.

Gilbert was astonished at the reproducible successional ecology in which the restroom surfaces consistently ended up at the same endpoint. He noted that this was a remarkable finding since most systems have the potential for multiple outcomes.

What About Toilet Seats?

Despite the overall reassuring results of the study, toilet seats in restrooms can still be potential hotspots for less pleasant microbes.

Researchers found that toilet seats in ladies’ rooms often harbored Lactobacillus and Anaerococcus, which are considered vaginal flora. Meanwhile, seats in men’s rooms tended to host bacteria from the intestinal tract such as Roseburia and Blautia.

Protecting Yourself from Harmful Bacteria

It’s always better to err on the side of caution when using public restrooms. Practice good hygiene by washing your hands thoroughly with soap and water after each restroom visit. The Centers for Disease Control and Prevention emphasizes that handwashing is the single most important practice for preventing the spread of bacteria and diseases.

When using public restrooms, it’s also a good idea to use toilet seat covers or clean the seat with a disinfectant wipe if available. Taking these steps will further reduce the risk of coming into contact with harmful microorganisms and bacteria.


While the thought of the bacteria lurking in a public restroom may be initially off-putting, this study has shown that the microbial communities are not as dangerous as you might have suspected. The harmful bacteria are often outcompeted by safer microbes, creating a relatively low-risk environment.

Nevertheless, always remember to prioritize personal hygiene and cleanliness to minimize your exposure to potentially harmful bacteria. Washing your hands and using toilet seat covers or disinfectant wipes will go a long way in keeping you safe and healthy in public restrooms.