语言朋友(11) For years we have been dieting strictly after the yearend overeating, afraid that when summer comes, the bigger size we have accumulated will betray how we ate.Now scientists say, it's a little bug that causes obesity(肥胖). As the holiday season with its abundant feasting arrives, millions of food lovers are keeping an eye on their figures.But scientists have found that weight gain is not about too much Christmas turkey or hot chocolates, but some bacteria in your guts(肠). Chinese scientists recently discovered a type of bacteria in guts that may be to blame for obesity. A research team led by Zhao Liping, a professor in Shanghai, has identified a precise link between a particular kind of bacteria and unusual weight gain. “The endotoxin(内毒素) released by the bacterium can activate(激活) a gene that helps produce fat.And it also deactivates a gene that consumes fat,” Zhao says. Scientists have long believed that microscopic organisms in the gut, microbiota, may play a very important role in weight gain, but they had never been able to prove it. In 2004, American microbiologist Jeffrey Gordon and his colleagues discovered a general link between obesity and gut microbiota in mice. While a link was believed to exist, proving it was another matter. “The list of diseases that they may play a role in is just growing and growing,” says Lita Proctor, director of the US National Institutes of Health.“But the problem is that we're only able to look at associations and aren't yet able to conduct causeandeffect studies.” |