Dr Karl Kruszelnicki has revealed the shocking reason you should always flush the toilet with the lid down.
The Australian scientist who has degrees in medicine and biomedical engineering has become a worldwide celebrity following his educational videos on the social media platform, TikTok with 467,000 thousand followers. And now the doctor's latest video is shocking followers.
Kruszelnicki took to the social media platform to share the alarming reason why you should only ever flush the toilet with the lid down, stating flushing with the lid up releases a "polluted plume of bacteria and water vapour just erupts out of the toilet bowl".
The scientist went on to say, "the polluted water particles float around for a few hours around your bathroom before they all eventually land".
"Some of them could even land on your toothbrush.
"So if you flush with the toilet lid up you could be brushing your teeth with toilet water."
Kruszelnicki finished the video with a joke saying "I guess that's one way to get the males in your household to put the lid down."
The video was posted earlier this week and has had over 332,000 thousand views with over 700 people taking to the comment section to share their reactions.
One TikTok user said, "Lid down and toothbrushes in the draw ALWAYS." While another user commented, "Not all the people in the comments saying it helps their immunity. I just don't want anything from inside the toilet on my toothbrush!!" to which the doctor replied "My thoughts exactly!"
A third person asked Kruszelnicki, "does this help our immune system Dr Karl?", he quickly replied with "In general, it's better to keep faeces away from food".
Many people also pointed out their toilet was separate from their bathroom, one user comments, "Says something about old bathrooms, so maybe they knew something making toilets separate from bathroom. I love having separate toilet from bathroom."