Artificial sweeteners - promoted as aids to weight loss and diabetes1 prevention - could actually hasten the development of glucose2 intolerance and metabolic3 disease, and they do so in a surprising way: by changing the composition and function of the gut4 microbiota - the substantial population of bacteria residing in our intestines5. These findings, the results of experiments in mice and humans, were published September 17 in Nature. Dr. Eran Elinav of the Weizmann Institute of Sciences Department of Immunology, who led this research together with Prof. Eran Segal of the Department of Computer Science and Applied6 Mathematics, says that the widespread use of artificial sweeteners in drinks and food, among other things, may be contributing to the obesity7 and diabetes epidemic8 that is sweeping9 much of the world. For years, researchers have been puzzling over the fact that non-caloric artificial sweeteners do not seem to assist in weight loss, with some studies suggesting that they may even have an opposite effect. Graduate student Jotham Suez in Dr. Elinavs lab, who led the study, collaborated10 with lab member Gili Zilberman-Shapira and graduate students Tal Korem and David Zeevi in Prof. Segals lab to discover that artificial sweeteners, even though they do not contain sugar, nonetheless have a direct effect on the bodys ability to utilize11 glucose. Glucose intolerance - generally thought to occur when the body cannot cope with large amounts of sugar in the diet - is the first step on the path to metabolic syndrome12 and adult-onset diabetes.The scientists gave mice water laced with the three most commonly used artificial sweeteners, in amounts equivalent to those permitted by the U.S. Food and Drug Administration (FDA). These mice developed glucose intolerance, as compared to mice that drank water, or even sugar water. Repeating the experiment with different types of mice and different doses of the artificial sweeteners produced the same results - these substances were somehow inducing glucose intolerance.Next, the researchers investigated a hypothesis that the gut microbiota are involved in this phenomenon. They thought the bacteria might do this by reacting to new substances like artificial sweeteners, which the body itself may not recognize as food. Indeed, artificial sweeteners are not absorbed in the gastrointestinal tract13, but in passing through they encounter trillions of the bacteria in the gut microbiota.The researchers treated mice with antibiotics14 to eradicate15 many of their gut bacteria; this resulted in a full reversal of the artificial sweeteners effects on glucose metabolism16. Next, they transferred the microbiota from mice that consumed artificial sweeteners to germ-free, or sterile17, mice - resulting in a complete transmission of the glucose intolerance into the recipient18 mice. This, in itself, was conclusive19 proof that changes to the gut bacteria are directly responsible for the harmful effects to their hosts metabolism. The group even found that incubating the microbiota outside the body, together with artificial sweeteners, was sufficient to induce glucose intolerance in the sterile mice. A detailed20 characterization of the microbiota in these mice revealed profound changes to their bacterial21 populations, including new microbial functions that are known to infer a propensity22 to obesity, diabetes, and complications of these problems in both mice and humans.词汇表：1 diabetes n.糖尿病参考例句：In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。2 glucose n.葡萄糖参考例句：I gave him an extra dose of glucose to pep him up.我给他多注射了一剂葡萄糖以增强他的活力。The doctor injected glucose into his patients veins.医生将葡萄糖注入病人的静脉。3 metabolic adj.新陈代谢的参考例句：Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。4 gut n.pl.胆量；内脏；adj.本能的；vt. 取出内脏参考例句：It is not always necessary to gut the fish prior to freezing.冷冻鱼之前并不总是需要先把内脏掏空。My immediate gut feeling was to refuse.我本能的直接反应是拒绝。5 intestines n.肠( intestine 的名词复数 )参考例句：Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句6 applied adj.应用的；v.应用，适用参考例句：She plans to take a course in applied linguistics.她打算学习应用语言学课程。This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。7 obesity n.肥胖，肥大参考例句：One effect of overeating may be obesity.吃得过多能导致肥胖。Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。8 epidemic n.流行病；盛行；adj. 流行性的，流传极广的参考例句：That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。9 sweepin