近年来炎症性肠病(IBD)、结肠癌发病率逐年增加。常用的治疗手段只能暂时缓解症状，但很快会出现耐药或毒副反应且预后差，这使IBD、结肠癌等肠道疾病成为严重威胁人类健康的疾病。因此寻找该疾病的发病原因迫在眉睫。越来越多证据表明，人工甜味剂三氯蔗糖的使用可能与世界范围的肠道疾病增加有关，但是关于三氯蔗糖提高肠道疾病发病率的机制却不甚清楚。我们的前期研究发现，三氯蔗糖影响肠道菌群微生态的平衡，而肠道菌群失调将会导致多种肠道疾病的发生发展，甚至癌症的发生。因此，本研究提出了“人工甜味剂三氯蔗糖的广泛使用可影响及改变肠道菌群微生态-消化蛋白酶的灭活障碍-肠道粘膜屏障破坏，进而引起肠道疾病反应，并提高肠道疾病的易感性”的假说。本课题拟通过对IBD和结肠癌模型动物的研究去验证假说，旨在揭示三氯蔗糖对肠道菌群影响与肠道疾病易感性提高的相关性，并阐明肠道菌群微生态改变影响肠道疾病易感性的作用机制。

In recent years, the incidence of inflammatory bowel disease (IBD) and colorectal cancer has been increasing year by year.Commonly used treatments give only temporary respite to symptoms, but soon the resistance or toxicity will appear and prognosis is poor, which makes IBD, colon cancer and other intestinal diseases become a serious threat to human health.Therefore, it is extremely urgent to find the cause of these diseases.There are increasing evidences that the use of artificial sweetener sucralose may be associated with an increase in intestinal diseases worldwide, but the mechanism of the increased incidence of intestinal disease by sucralose is not clear. Our previous study found that sucralose effected the microbial balance of intestinal microflora, and intestinal flora imbalance will lead to the development of a variety of intestinal diseases, and even the occurrence of cancer. Therefore, this study proposes the hypothesis that the widely use of artificial sweetener sucralose could influence and change the gut microflora to trigger disorder of digestive protease inactivation and damage of intestinal mucosal barrier, then cause intestinal disease reaction and increase susceptibility to intestinal diseases. This study intends to verify the hypothesis by the studies of IBD and colon cancer on model animals to illuminate relationship between the effect of sucralose on intestina flora and increased susceptibility to intestinal diseases, elucidating the mechanism by which alteration of intestinal flora induce intestinal diseases.