巴氏杀菌发酵乳改善DSS诱导结肠炎小鼠症状的研究

Study on the Improvement of Symptoms of DSS-induced Colitis in Mice by Pasteurized Fermented Milk

本研究采用3.5%的葡聚糖硫酸钠(DSS)构建小鼠结肠炎症动物模型,旨在阐明巴氏杀菌发酵乳对结肠炎小鼠的缓解作用及可能的机制。通过评估小鼠疾病活动指数(disease activity index,DAI),HE染色观察结肠组织病理切片,气相色谱-质谱联用(GC/MS)分析肠道短链脂肪酸含量,ELISA检测结肠组织中的炎症因子水平,检测髓过氧化物酶(MPO)含量和采用免疫组化进行紧密连接蛋白的表达,来研究巴氏杀菌发酵乳的作用。结果表明,巴氏杀菌发酵乳可以降低结肠炎小鼠疾病活动指数DAI、缓解结肠组织损伤、增加小鼠肠道短链脂肪酸乙酸、异丙酸、戊酸和总酸的含量,同时降低小鼠促炎细胞因子肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)的分泌、增加抗炎细胞因子白细胞介素-10(IL-10)的分泌和降低MPO活性。进一步的研究表明,巴氏杀菌发酵乳可以增加小鼠肠道紧密连接蛋白的表达,增强肠道上皮屏障功能。因此,巴氏杀菌发酵乳可以缓解小鼠肠道炎症症状,并且可能是通过调节免疫功能和增强肠道屏障发挥其作用。

In this study,3.5% DSS was used to construct an animal model of colonic inflammation in mice,in order to study the relieving effect of commercially available pasteurized fermented milk on colitis mice and the possible mechanism.The effect of pasteurized fermented milk was studied by evaluating the disease activity index(DAI) in mice,observing colon tissue structure by HE staining,analyzing intestinal short-chain fatty acid content by gas chromatography-mass spectrometry(GC/MS),detecting inflammatory factors in colon tissue by ELISA levels,measuring myeloperoxidase(MPO) content and using immunohistochemistry for tight junction protein expression.The results of the study showed that pasteurized fermented milk could reduce the disease activity index DAI,alleviate colon tissue damage,increase the content of acetic acid,isopropionic acid,valerate acid and total acid in the intestinal short-chain fatty acids of mice,reduce the secretion of anti-inflammatory cytokines tumor necrosis factor-α(TNF-α) and leukocyte-mediated interleukin-1β(IL-1β) in mice,and increase the anti-inflammatory cytokines interleukin-10(IL-10) secretion and decrease MPO activity.Further research showed that pasteurized fermented milk could increase the expression of tight junction proteins in the mouse gut and enhance intestinal epithelial barrier function.Therefore,pasteurized fermented milk could not only alleviate the symptoms of intestinal inflammation in mice,but might play its role by regulating the body’s immunity and strengthening the intestinal barrier.