via my favourite drug dealer, JR, this summary:
The investigators looked specifically at the germs E. coli and Staphylococcus aureus to see if the foods picked them up after being left on the floor for between 3 and 30 seconds.
The time the food spent on the floor and the type of flooring both had effects on the likelihood of transfer of germs. More time translated to more germs, while carpet was the least likely to transfer bacteria; laminated and tiled floods boosted the risk that germs would transfer to moist foods after 5 seconds or more.
For some foods, I'm willing to observe the five-minute rule.