For centuries, people have debated whether the toilet seat should be left up or down. However, the more important question is whether the toilet lid should be up or down when you flush.
The answer is simple but disgusting, as it involves something known as "faecal mist." According to Dr Karl, a well-known scientist, when you flush, a mixture of bacteria and water vapour erupts from the water bowl and some of it can even land on your toothbrush. This means that you may end up brushing your teeth with toilet water, which is gross.
A recent study has provided visual evidence of the issue. Researchers attached a laser beam to a toilet bowl to demonstrate the plume of toilet matter that sprays into the air, and it is just as repulsive as it sounds.
So, the rule for good hygiene is to put the toilet lid down before flushing. If you insist on keeping the lid up, at least ensure that you close your mouth when standing near the bowl to flush. Some commenters have suggested keeping the toilet in a separate room from your toothbrush to avoid any risk of contamination.