食物掉地上捡起来可以吃：科学证明

Lincoln: Now, would you eat food that’s been dropped on the floor? Michael, tell us a little bit more about this. Michael: OK. Well, I’m sure you’ve both heard of the “five-second rule”. So, there’s this mythical rule that any food picked up from the floor is perfectly fine to eat within five seconds of dropping it, so to find out whether this is true, or whether this is an old wives’ tale, the BBC recently put this question to some scientists who specialize in microbes and bacteria and things of that nature. So, to give you a bit of context and a bit of a backgrounder, it’s not like there’s a swarm of bacteria lying on the ground, just waiting to pounce on any food that falls from the table. You know, bacteria is absolutely everywhere, even if you’ve just mopped and bleached the floor and you can see your face in it. There’s bacteria absolutely everywhere. At any one time, there are about 9,000 different species of microscopic creatures in the dust in your home and everywhere like that, 7,000 of which are different bacteria – you know, they’re on your hands, on your face, on your skin, and in fact, each person emits around 38 million bacterial cells into their environment each hour. One of these scientists, a man called Jack Gilbert who is a microbial ecologist at the University of Chicago, he said even licking your floor or toilet seat is unlikely to make you sick. However, he did say that it’s probably not clever to do that if someone in your household is sick or if you are in a country with poor hygiene records. Lincoln: I do think it depends on what you drop. If you drop something dry and you pick it up immediately, I wouldn’t mind as much, but if you drop something wet [Michael: Like smoked salmon] some salmon, or tuna, then you should probably just let that one go. Wu You, I see you smiling over there. What do you think of this? WY: It quickly reminds me of a cartoon that I saw not long ago. It says that one piece of chip fell on the floor, and the bacteria cell is talking to his peers: “Don’t anybody touch that chip yet! One…two…three…four…” Lincoln: Yeah, kind of making fun of the whole idea, as well. But in China, as well, I remember the first time I came here, if you’re eating at a restaurant, I was told that if something falls off the plate, it’s dead to you. You never pick it up and eat it – it’s gone forever! But one thing I’ve also noticed, just about putting things on the floor is I’ve noticed that a lot of – it seems – foreigners don’t mind putting their bags and stuff on the floor, and Chinese people would never do this. WY: Never do that! Never ever! Lincoln: I’ve put my backpack on the floor in the subway, in the office, everything. [WY: That’s the worst] You see? But it’s just like, I’m not wearing it, so in my head, it doesn’t make a big difference to me, I’m not wearing it. Michael: You know, when Chinese people go into the house, they immediately change out of their shoes and into slippers [Lincoln: Yeah, that’s interesting] and I wonder if, maybe because China generally is a little bit more dusty and dirty, like when you’re walking around… WY: No, because people believe that on the streets outside there has been more bacteria on the floor, but inside of your house, you clean it every day, so you need to change your shoes in case you bring the bacteria from outside onto your clean floor. Lincoln: Yeah, well, that’s something that’s not a big thing in South Africa, never do that. No one’ll ever ask you to take off your shoes going into a house. In fact, if you go to someone’s house and you have to take off your shoes, you might as well just go “you know what? Actually, I don’t want to visit you”. [WY: Is it that bad?] It’s a bit crazy, it’s a bit weird. WY: Sometimes, especially for some families who have babies, and the babies are just crawling on the ground and just lying down on the ground, if someone else brings the bacteria from outside and didn’t change shoes, maybe the shoes will bring some bad bacteria into the floor and then the baby might touch it. Lincoln: Well, I think babies need to encounter as much bacteria as possible, because that’s necessary for them, they need to actually build up their immunities and stuff.