考研英語時文賞讀（143）：為什么甜食吃多了不好？

　　Simple Sugars Wipe Out Beneficial Gut Bugs

　　單糖會破壞腸道益生菌

　　We all know that stuffing our faces with sweet treats is not good for us.

　　我們都知道，吃太多的甜食對我們的身體沒有好處。

　　In part because it's bad for the health-promoting bacteria that inhabit our intestines. Now, researchers have figured out how simple sugars wipe out a particular strain of beneficial gut microbes.

　　部分原因是甜食會破壞我們腸道內對健康有益的細菌。如今，研究人員發(fā)現(xiàn)了單糖是如何對一種特殊的腸道益生菌造成破壞的。

　　"The underlying assumption that existed in the literature was that simple sugars such as fructose and sucrose which are prevalent in Western diet are not good for humans." Yale professor of Microbial Pathogenesis Eduardo Groisman, who led the study.

　　主導這項研究的耶魯大學微生物病原學教授愛德華多·格羅伊斯曼說：“文獻中的基本假設是，西方飲食中普遍存在的果糖和蔗糖不利于人體健康。”

　　Simple sugars—like those in high fructose corn syrup or the table sugar formally known as sucrose—were thought to be absorbed in the small intestine, so a lot of our gut bacteria would never actually be exposed to them.

　　此前人們認為，諸如高果糖玉米糖漿或食糖（正式名稱為蔗糖）中的單糖是在小腸中被吸收的，因此許多腸道細菌是接觸不到單糖的。

　　Because fiber and complex carbs, made of long chains of sugar molecules, are harder to digest, they make it all the way to the large intestine, where they promote the growth of good bugs like Bacteroides thetaiotaomicron—a microbe found in individuals who are healthy and lean.

　　由于纖維和由長鏈糖分子構成的復合碳水化合物很難被消化，所以它們會一路來到大腸，促進大腸中的多形擬桿菌（一種在健康、苗條者體內發(fā)現(xiàn)的微生物）等益生菌的生長。

　　"But now what our work actually shows is that both fructose and sucrose do make it to the colon where the microbiota exist. And second that these sugars impact a good bacterium even though nutrition is not involved."

　　“但現(xiàn)在我們的研究實際上表明，果糖和蔗糖確實能到達有微生物群存在的結腸。雖然這些單糖并不為它們提供營養(yǎng)，但還是會對益生菌產生影響。”

　　In other words, the bacteria are not using fructose and sucrose as food. Instead, the sugars serve as signals that shut down production of a protein that beneficial Bacteroides need to colonize the intestine.

　　換句話說，這些細菌不會將果糖和蔗糖作為食物。相反，單糖作為一種信號抑制了有益的擬桿菌在腸道內定植所需蛋白質的產生。

　　The findings appear in the Proceedings of the National Academy of Sciences. Groisman says he'd like to explore whether complex polysaccharides can save Bacteroides from this sugary death sentence. Because then maybe we can eat cake and have our gut bugs too.

　　這項研究結果發(fā)表于《美國國家科學院院刊》上。格羅伊斯曼表示，他想探究復合多糖能否使擬桿菌免于這種“甜蜜的死刑判決”。因為這樣也許我們就既能吃蛋糕，又能保護我們的腸道益生菌。

　　(全文共286個詞)

　　重難點詞匯：

　　intestine  n. 腸；腸道 adj. 內部的；國內的

　　prevalent  adj. 流行的；普遍的，廣傳的

　　absorb  vt. 吸收；吸引；承受；理解；使…全神貫注