You might want to think twice next time you brush your teeth, as there might be more than just Colgate on your toothbrush.
According to experts, you could be brushing your teeth with someone else's poo. Yep, lovely, eh?
If you keep your brush in the bathroom - where else do you keep it? - the chances are it is covered in faecal matter which is floating around in the air after every flush of the toilet.
Unless you close the lid when you pull the chain, particles are flung into the air which land on the bristles of the toothbrush and can harbour bugs like E. coli and norovirus.
The study found that a toothbrush can contain at least 200,000 bacteria per square inch - more than the average toilet seat.
Hygiene expert Ralitsa Prodanova told the Metro: "These bio-aerosols can be extremely harmful - and the airborne water droplets are often contaminated with viruses and bacteria.
"Previous scientific studies have shown how E. coli, Clostridium difficile and norovirus can all be transmitted in this way.
"And if you keep your toothbrush near your toilet, these potentially deadly bugs can land on the bristles - before you put them straight into your mouth, twice a day.
"Toothbrushes themselves are the perfect breeding ground for germs."
A study at Quinnipiac University in the United States of America, found there is a 60 per cent chance that a toothbrush is spattered with faeces. Mmmm.
While those who use communal bathrooms with an average of nine people had an 80 per cent chance the faeces belonged to another person.
Researcher Lauren Aber told Science Daily it was a big health risk.
She said: "The main concern is not with the presence of your own faecal matter on your toothbrush, but rather when a toothbrush is contaminated with faecal matter from someone else, which contains bacteria, viruses or parasites that are not part of your normal flora."
The study also found that it doesn't matter how much mouthwash or hot water you cover your toothbrush in, it won't make a difference - and neither will a cover.
Aber added: "Using a toothbrush cover doesn't protect a toothbrush from bacterial growth, but actually creates an environment where bacteria are better suited to grow by keeping the bristles moist and not allowing the head of the toothbrush to dry out between uses."
Maybe it's time to invest in a new toothbrush.