簡介： A protein found in spit prevents bad bugs from binding to intestinal cells in the lab, pointing to a possible way to lower the chances of dysentery. Christopher Intagliata reports.
在實驗室裡，一種於唾液中發現的蛋白質可以防止害蟲與腸細胞結合，這為我們提供了一種降低患上痢疾可能性的方法。克里斯托弗·因塔利亞塔報道。
撰文/播音：克里斯托弗·因塔利亞塔（Christopher Intagliata）
翻譯：姜帆
審校：郭曉
Every day, you produce one to two liters of spit. It kick-starts digestion and helps you swallow. And it helps prevent bacterial infection in your mouth.
每天，你都會產生一到兩升的唾液。它啟動消化並幫助你吞嚥。而且它還有助於防止口腔內細菌感染。
"But that still seemed like a lot of energy put into something if it's only going to do that small task." Esther Bullitt, a biophysicist at the Boston University School of Medicine. "And we wondered whether there was something else it was doing as well, if maybe it had a farther reach than just preventing infections in the mouth."
“但是，如果只有那麼一點用處，那麼唾液似乎有點大材小用了。”波士頓大學醫學院生物物理學家艾斯特·布利特（Esther Bullitt）說道。“我們想知道它是否還有其他功能，或許它除了預防口腔感染外還有更多的作用。”
So she and her team looked farther down the pipes—at whether certain proteins in spit might also disrupt the work of bad bugs in the gut. They grew cells taken from the small intestine of a 51-year-old woman. They also grew a batch of pathogenic E. coli bacteria, the kind that cause traveler's diarrhea. The E. coli have hairlike extensions, called pili, that grab onto the intestinal cells. But fewer of the E. coli were able to successfully attach to the intestinal cells when a particular saliva protein, called histatin-5, was hanging around.
因此，她和她的團隊對唾液進行了進一步的研究——唾液中的某些蛋白質是否也可能阻止腸道中有害細菌的破壞作用。他們培養了從一名51歲女性的小腸中獲取的細胞。他們還培養了一批致病性大腸桿菌，這種細菌會導致旅行者腹瀉。大腸桿菌具有毛狀突起，稱為菌毛，菌毛能抓住腸細胞。但是當有特定的唾液蛋白組氨素抑制素-5在其周圍時，能夠成功附著在腸細胞上的大腸桿菌數量將減少。
You can think of the E. coli like pirate ships, trying to dock at a port. What the histatin-5 does is stop the pirate ships, the bad bugs, from using their ropes—the pili—to dock. "If you can't bind, then you can't start an infection. So no adhesion, no infection, no disease."
你可以把大腸桿菌想象成海盜船，它們試圖停靠在一個港口。組氨素抑制素-5所做的是阻止海盜船（有害細菌），使用它們的繩索——菌毛——到達碼頭。“如果大腸桿菌不能與腸細胞結合，那麼它們就無法進行感染。所以沒有粘連，就沒有感染，也就沒有疾病。”
The study is in The Journal of Infectious Diseases. [Jeffrey W. Brown et al., A Role for Salivary Peptides in the Innate Defense Against Enterotoxigenic Escherichia coli]
這項研究發表於《傳染病雜誌》（The Journal of Infectious Diseases）。
The salivary protein can be chemically synthesized; stored as a powder; and dissolved in water. And presumably, the resulting liquid is safe. "You know that your body tolerates it, because you swallow one to two liters of it every day." No word yet on whether it might someday be available at the drugstore. But the good news is: you're already swallowing some right now.
唾液蛋白質可以化學合成; 以粉末形式儲存; 且溶於水。據推測，溶解後得到的液體是安全的。“你知道你的身體默認它的存在，因為你每天吞下一升到兩升。”目前還不知道以後是否有可能在藥店買到這種蛋白質。但好消息是：你已經在吞嚥一些唾液了。
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