The Truth About Your Toothbrush’s Bacteria

Covered in feces? Here’s what the microbes say

Is this woman putting a clean, safe toothbrush in her mouth? Or is she essentially brushing her MOUTH with her BUTT? Photo by Diana Polekhina on Unsplash

Growing up, I think one of my most disturbing “cool science facts” that I parroted around was the idea of fecal spread from flushing toilets.

I’m sure you’ve heard it in some form; when you flush a toilet, all of the… human waste, shall we say… doesn’t just get sucked down the drain to never be seen again. The energetic flush also sends micro-droplets of water into the air — and those droplets also carry tiny little bits of feces.

This phenomenon has been studied and examined, and it’s known as a “toilet plume”. Depending on the model of toilet, the power of the flush, and whether the lid is closed, this plume can spread droplets more than three feet away from the toilet.

This raises some concerning questions about the other contents of a bathroom — namely, the toothbrush. Many toothbrushes, when not in mouths, sit out on counters or next to sinks. Mine does.

How dirty is my toothbrush? When I brush my teeth, am I using the equivalent of “butt toothpaste?”

A recent study from Northwestern University decided to perform an examination of toothbrushes to answer this question. They decided to examine the microbiome, the collection of different bacteria living on the…