饮食脂肪可能引发肠道炎症
Fat and gut disorders
来源：华尔街日报    2012-08-06

        Saturated milk fat, a common ingredient of many processed foods, can trigger the production of harmful bacteria that disrupt the intestinal environment, resulting in colitis and other inflammatory bowel diseases in genetically susceptible individuals, according to a report in the journal Nature. Inflammatory bowel diseases are relatively new disorders that have increased over the past half century, possibly because of dietary fats in Western diets, researchers said.         
        Experiments conducted at the University of Chicago compared the effects on the intestinal organisms of mice from three separate diets─one that was low in fat, another high in saturated milk fat, and a third that was high in polyunsaturated safflower oil. The saturated fat content for the diets was 0.6%, 65% and 39%, respectively. The diets were fed to two groups of mice─one genetically bred to develop inflammatory bowel disease and another that was genetically normal. After 21 days, a bacterium called Bilophila wadsworthia, normally associated with appendicitis and other inflammatory disorders, was found in the intestines of mice on the saturated-milk-fat diet but not in other mice.         
        In the intestines of the genetically susceptible mice, the bacteria triggered an inflammatory immune response, researchers said. Over the next six months, the incidence of colitis in these mice doubled to over 60%. However, the saturated-milk-fat diet had no effect on genetically normal mice. And the two other diets─low-fat and polyunsaturated─weren't associated with colitis, the researchers said.         
　　脂肪和肠功能失调：根据《自然》（Nature）期刊发表的一份报告，作为许多加工食品的一种常用配料，饱和乳脂肪能引起有害细菌的产生，扰乱肠道环境，导致基因易感人群患结肠炎及其他肠道炎症。研究人员说，肠道炎症是比较新的病症，在过去半个世纪发病率有所上升，可能是由于西方饮食中的膳食脂肪引起。 
　　在芝加哥大学（University of Chicago）开展的实验中，研究人员用三种不同的食物喂食小白鼠，观察三种不同饮食对小白鼠肠道有机体的影响──一种是低脂肪，一种饱和乳脂肪含量较高，第三种多不饱和红花油含量较高。三种饮食的饱和脂肪含量分别为0.6%、65%和39%。研究人员给两组小白鼠喂食这些食物，一组拥有肠道炎症的基因，另一组基因正常。21天后，在喂食饱和乳脂肪含量高饮食的小白鼠肠道中发现了一种名为Bilophila wadsworthia的细菌，另一组小白鼠没有。这种细菌一般与阑尾炎或其他炎症有关。 

　　研究人员说，在基因易感小白鼠的肠道内，这种细菌引发了炎症免疫反应。接下来的六个月里，这些小白鼠的结肠炎发病率涨了一倍，达到60%以上。然而，饱和乳脂肪含量高饮食对基因正常的小白鼠没有影响。研究人员说，另外两种饮食──低脂肪和多不饱和红花油──与结肠炎没有关联。 
        Caveat: The research hasn't been tested in human subjects.          注意：尚未对人类进行过此类研究。 
        Title: Dietary-fat-induced taurocholic acid promotes pathobiont expansion and colitis in Il10-/-mice          论文标题：《饮食脂肪产生的牛磺胆酸会加速拥有白细胞介素-10小鼠的pathobiont扩张并增加结肠炎发病率》（Dietary-fat-induced taurocholic acid promotes pathobiont expansion and colitis in Il10-/-mice）