"Poo particles can contain E. coli, salmonella, or even norovirus, all of which, if present in high enough concentrations, can make us sick – but not from sitting on the toilet seat." ...
When you flush, the water in the toilet bowl mixes with waste - be it urine, poop, or vomit - and tiny particles of this mixture are emitted into the air. These droplets are known as toilet plume.