They’re just germs to us, but scientists find microbes nothing short of miraculous — the keys to human health. In fact, the American Museum of Natural History is devoting an entire exhibit to bacteria, “The Secret World Inside You,” opening Saturday.
“Some bacteria are actually good for you. They’re the first line of defense against dangerous bacteria,” says the show’s co-curator, microbiologist Susan Perkins. “Where we once saw microbes as enemies to combat, we now understand that most are actually allies.”
Here are a few facts that may dazzle or disgust you. Or both.
1. You have more bacteria on one of your hands than there are people on this planet — more than 7 billion bacterial cells on each. And since our right and left hands do different things, they have different kinds of bacteria.
2. You’ll never dream what your pillowcase shares with your toilet seat. “They both touch cheeks,” Perkins explains, “and since both cheeks are slightly dry, they [harbor] similar bacteria.” Those bacteria aren’t harmful, she adds.
3. French-kissing gives you more than you bargained for, Perkins says: One 10-second round of tongue hockey is long enough to transfer 50 million microbes. “You’re not just swapping spit — you’re swapping bacteria.”
4. Your own mouth harbors 200 different species of bacteria, most of them harmless. But bacteria converts sugar into acid, which causes cavities, so drop that leftover Halloween candy.
5. Location, location, location. “Every one of our teeth has a different community on it,” Perkins says. “The backs of our teeth are more exposed to our tongues, the fronts of our teeth to air.” Different environments breed different bacteria, some of which actually protect you against the microbes that cause tooth decay. And take it easy with the antibacterial mouthwash: Removing too many bacteria can lead to fungal infections, thrush among them.
6. Nothing breeds familiarity like a dog. Perkins says that the dog’s family members have more bacteria in common with each other than in canine-free households, since everyone’s petting and sharing whatever the dog’s picking up from outside. “But that doesn’t work with cats,” she says. “My guess is that cats are more attuned to a single member of the family.” Or maybe they just don’t get out enough.
7. Two words that could save lives: fecal transplants. Gut bacteria from a healthy person can cure one of the deadliest bacteria out there, the antibiotic-resistant Clostridium difficile, which can cause diarrhea or even death. Perkins says work is under way on putting human stool into capsule form, to make it easier to swallow. There’s even talk about banking your own poo for use in emergencies. Wonder what they’ll call that bank.
8. Why the Japanese are stronger than we are (non-car division). “Most people who eat seaweed can’t digest it,” Perkins says. But many Japanese people can, thanks to a gene from aquatic bacteria they probably acquired from years of eating sushi. That in turn helps them get the most energy out of their tekka maki.
9. The single germiest thing you own? Probably your cellphone. “It’s replaced the magazine as something you take everywhere, including the subway and the bathroom,” Perkins says. “And then you put it against your face!” Which is why she wipes down her own phone once a day with disinfectant.
10. “If you took all the bacteria living in your body, it would weigh the same amount as your brain — about 2 to 3 percent of your body weight,” Perkins says. “So I just subtract two pounds whenever I get on the scale!”