动物实验 z-bo 2020-09-24 421

　　This sounds like a health shift, but sometimes people who drink sugar-free soft drinks gain more weight and suffer from chronic diseases such as diabetes. This has always puzzled nutritionists, but now experiments in mice show that, in some cases, this is partly due to the artificial sweetener-aspartame. Related results were recently published in the journal "Applied Physiology, Nutrition and Metabolism".

　　The calorie-free artificial sweetener is a synthetic substitute for sugar, and its sweetness is up to 20,000 times that of sugar. They are commonly used in products like zero-calorie drinks, sugar-free desserts, and are sometimes recommended for people with type 2 diabetes.

　　However, experiments in mice have shown that when aspartame is broken down in the intestines, it may disrupt the process essential to neutralizing harmful toxins from intestinal bacteria. By interfering with a key enzyme, these toxins will gradually accumulate, irritate the intestinal wall and trigger mild inflammation that may eventually lead to chronic diseases.

　　"Our results provide a new mechanism to explain why Abbastian does not always keep people slim, and may even cause problems such as obesity, heart disease, diabetes, and metabolic syndrome." From Boston, USA Richard Hodin of Massachusetts General Hospital said.

　　"Decades of scientific research, including human clinical trials, have shown that low-calorie sweeteners can help consumers manage their calorie intake when they become part of an overall healthy diet." said Gavin Partington from the British Soft Drinks Association. "The latest findings were obtained through research in mice, and are contrary to overwhelming scientific evidence."

　　The problem is an enzyme called intestinal alkaline phosphatase (IAP). "There are many IAPs in the human intestines. It seems to protect us and allow us to coexist with bacteria." Hodin said.

　　IAP works by neutralizing the bacterial toxin that stimulates the intestinal wall-lipopolysaccharide. However, when Hodin's team mixed IAP with a beverage containing aspartame in the laboratory, the latter weakened the enzyme's activity. In contrast, when it was mixed with sugar-sweetened beverages, this did not happen. When the team injected Abbastian into the intestinal fragments of mice, IAP levels plummeted by 50%.

　　The study also found that when consumed with high-fat foods, aspartame may make mice gain more weight. When Hodin's team allowed mice to eat high-fat food for 18 weeks, the mice that also consumed aspartame became fatter.