Toothbrushes and their little friends



So today’s post might have some people cringing and others reaching for a new toothbrush.

I, like many other big city dwellers, live in a small apartment where my toilet is located in the bathroom. It is in very close proximity to the sink where I keep my toothbrush. Hence I always keep the lid closed on the toilet, particularly when flushing. It seems to me, however, that I may be in the minority of people who do this.

So why am I writing about this? Why should it matter, you ask? Simple. Aerosols. Aerosols from the toilet landing on my toothbrush.

I’ll let you savor that image.

It’s all about the microbiota

A study in 2012 demonstrated that bathrooms were covered in microbes found in toilet aerosols generated by flushing a toilet with the seat up. These microbiota were also found on toothbrushes. While this study highlighted how far the toilet aerosols can travel, it also revealed that toothbrushes are inherently contaminated.

A review of the literature into studies investigating toothbrush contamination revealed that toothbrushes are coated in oral microbiota as well as microbiota from the surrounding environment. Interestingly, contamination was found to be influenced by the size of the handle and bristles.

While this sounds horrifying to think that our toothbrushes are contaminating us, we should remember that toothbrushes actually remove the bacteria from our mouths that can cause periodontal disease. Furthermore, bacteria that make it to the gut can be outcompeted by the gut microbiota. Only people who are immune compromised or who are suffering from severe periodontal disease should be worried.

A final word

Despite these unsettling discoveries, it is recommended that you change your toothbrush frequently and, to add my own two cents, perhaps put the lid down when you flush the toilet if your toothbrush is nearby??


Montero, Elly A., et al. “The Effects of Proximity on Aerosol Distribution of Bacteria on Toothbrushes.” Journal of the California Dental Hygienists’ Association 27.2 (2012).

Frazelle, Michelle R., and Cindy L. Munro. “Toothbrush contamination: a review of the literature.” Nursing research and practice 2012 (2012).