摘要目的 评估植物乳杆菌（Lactobacillus plantarum，Lp）对白细胞介素-10基因敲除(interleukin-10 knockout，IL-10-/-)小鼠结肠炎的治疗作用，并探讨其可能的作用机制。方法 8周龄雌性IL-10-/-小鼠和WT小鼠各20只，各自平均分成2组，即WT组、WT+Lp组、IL-10-/-组和IL-10-/- +Lp组。WT和1L-10-/-组予0.5 ml PBS灌胃，WT+ Lp和IL-10-/-+ Lp组予0.02g Lp(0.5 ml)灌胃，每天摄入Lp1×109菌落形成单位(CFU),持续灌胃4周后实验结束。实验开始前（0周）及开始后每隔1周收集小鼠新鲜粪便1次，直至实验结束。实验结束后将小鼠处死，记录各组小鼠体重变化，并测量其结肠长度和湿重，切取新鲜结肠组织标本做病理切片及结肠黏膜促炎因子肿瘤坏死因子(TNF)-α和干扰素-γ(IFN-γ)检测。并对小鼠新鲜粪便作选择性细菌培养，观察Lp在正常小鼠和炎症小鼠体内的定植情况及其对肠道菌群的调节作用。结果 与WT小鼠相比，IL-10-/-小鼠腹泻较重，体重亦明显下降(P＜0.05)，存在严重营养不良，而经Lp治疗后IL-10-/-小鼠腹泻得到缓解，体重亦明显增加(P＜0.05)。病理学检查显示，所有IL-10-/-小鼠皆发生肠道炎症，经Lp治疗后肠道炎症得到明显改善，黏膜溃疡、上皮增生及黏膜固有层淋巴细胞和中性粒细胞浸润明显减轻，病理学评分明显降低(P＜0.01)。IL-10-/-小鼠经Lp治疗后结肠湿重及湿重与长度比出现明显变化(P＜0.01)，结肠水肿和增厚现象得到明显改善。IL-10-/-组小鼠结肠TNF-a和IFN-γ含量分别为(377.4±84.4) μg/g和（602.6±108.1）μg/g，均较WT组明显增加[（139.2±32.7）μg/g和（173.0±52.4）μg/g，P＜0.05）]。Lp干预4周后，IL-10-/- +Lp组小鼠结肠TNF-α和IFN-γ的含量分别为(207.2±65.7) μg/g和(442.1±138.4) μg/g，均较IL-10-/-组显著降低(P＜0.05)。IL-10-/-小鼠体内肠道菌群出现紊乱。结论 Lp能有效减轻IL-10-/-小鼠肠道炎症，对结肠炎起到一定的治疗作用，且这种治疗作用与Lp调节肠道菌群及抑制促炎细胞因子的表达有关。

abstractsObjective To evaluate the role of Lactobacillus plantarum (LP) in the treatment of colitis in interleukin (IL)-10 knockout (IL-10-/-) mice and to explore its possible mechanisms.Methods Eight weeks old female wildtype (WT) mice and IL-10-/- mice, twenty mice of each type,were randomly assigned to four groups, WT group, WT+ LP group, IL-10-/- group and IL-I0-/- +LP group. The WT and IL-10-/- mice were gavaged with 0.5 ml saline, WT+Lp and IL-10-/- +Lp groups were gavaged with Lp 0.02 g (0.5 ml) ,took Lp 1 × 109 cfu everyday,continued for 4 weeks and then the experiment finished. The fresh mice faeces was collected once every week before (week 0) and during the experiment. The mice were executed at the end of experiments, the change of mice weight Was recorded, the length and the wet weight of colon were measured, fresh colon tissue specimens were taken for biological slices and proinflammatory cytokines TNF-a and IFN-γ were measured in colon mucosa. The fresh faeces were selectively cultured. The colonization of Lp in normal and colitis mice and its regulation role in intestinal flora were observed. Results Compared with WT mice, IL-10-/- mice demonstrated severe diarrhea, significantly decreased in body weight (P ＜0.05)and serious malnutrition. After Lp treatment, diarrhea relieved in IL-10-/- mice and the body weight increased significantly (P＜0.05). Pathological examination suggested that 100％ of IL-10-/-mice had intestinal inflammation, however after Lp treatment intestinal inflammation improved significantly. Mucosal ulcer, epithelial hyperplasia, the infiltration of neutrophils and lymphocytes in the lamina propria were also significantly reduced.The histopathological score was significantly lowered (P＜0.01). After Lp treatment, colon wet weight and the ratio of wet weight to length of IL-10-/- mice changed significantly (P＜0.01). Colon edema and thickening improved remarkably. The TNF-a and IFN-γ concentration of colon in IL-10-/- mice were 377.4±84.4 μg/g and 602.6±108.1 μg/g,which increased obviously than WT group (139.2 ± 32. 7 μg/g and 173.0± 52.4 μg/g, P＜0.05). After treated with Lp for four weeks, the TNF-α and IFN-γ concentration of colon in IL-10-/-+Lp group mice were 207.2±65.7 μg/g and 442.1 ± 138.4 μg/g, both were lower than that of IL-10-/- group mice (P＜0.05). The intestinal flora was disrupted in IL-10-/- mice. Conclusion Lp can effectively reduce intestinal inflammation in IL-10-/- mice, which take certain part in treatment in colitis. This treatment effect is associated with intestinal flora regulation and the inhibition of proinflammation cytokines expression.