Inflammatory bowel disease (IBD) is a group of chronic inflammatory gastrointestinal diseases that causes worldwide suffering. L. helveticus is a probiotic that can enhance intestinal barrier function via alleviation of excessive inflammatory response. Citrulline, a functional amino acid, has been reported to stimulate muscle synthesis and to function with a prebiotic-like action with certain Lactobacillus strains. The aim of this study was to investigate the potential synergistic effect of combining L. helveticus and citrulline on protection against damage induced by dextran sulfate sodium (DSS) in a mouse model. 6-week-old male C57BL/6J mice were fed with DSS water and randomly divided for administering with different milk treatments: 1) plain milk (control or DSS control), 2) 1% (w/v) citrulline enriched milk (Cit_milk), 3) milk fermented with L. helveticus (LHFM) and 4) DSS+milk fermented with L. helveticus with 1% (w/v) citrulline (Cit_LHFM). The treatment effects on the survival and macroscopic and microscopic signs were examined. All treatments presented different degrees of protective effects on attenuating the damages induced by DSS. All treatments reduced the body weight loss, disease activity index (DAI), histological scores, pro-inflammatory cytokine expression (IL-6, TNF-α and IFN-γ) and production (IL-4) (all P <0.05) and the tight junction (TJ) protein (zonula occluden-1 (ZO-1) expression. LHFM and Cit_LHFM improved survival rate (both at P<0.05). Particularly, Cit_LHFM showed greater effects on protecting the damages induced by DSS, especially in ameliorating colonic permeability, TJ protein (ZO-1, occludin and claudin-1) expression and distribution as well as in reducing IL-4 and IL-17 expression (all P <0.05). Our findings suggested that the combination of and citrulline had significant synergistic effect on protecting against injury from DSS-induced colitis. Therefore, citrulline enriched L. helveticus fermented milk is suggested to be a potential therapy for treating IBD.

炎症性肠病 (IBD) 是一组慢性炎症性胃肠道疾病，可导致全球范围内的痛苦。L. helveticus是一种益生菌，可通过减轻过度炎症反应来增强肠道屏障功能。据报道，瓜氨酸是一种功能性氨基酸，可刺激肌肉合成，并与某些乳酸杆菌菌株具有类似益生元的作用。本研究的目的是研究联合L. helveticus的潜在协同效应和瓜氨酸对小鼠模型中葡聚糖硫酸钠 (DSS) 引起的损伤的保护作用。给 6 周大的雄性 C57BL/6J 小鼠喂食 DSS 水，并随机分配给不同的牛奶处理：1) 纯牛奶（对照或 DSS 对照），2) 1% (w/v) 富含瓜氨酸的牛奶 (Cit_milk )、3) 瑞士乳杆菌发酵乳(LHFM) 和 4) DSS+瑞士乳杆菌发酵乳含 1% (w/v) 瓜氨酸 (Cit_LHFM)。检查治疗对生存和宏观和微观体征的影响。所有处理对减轻DSS引起的损伤均表现出不同程度的保护作用。所有治疗均降低体重减轻、疾病活动指数 (DAI)、组织学评分、促炎细胞因子表达 (IL-6、TNF-α 和 IFN-γ) 和产生 (IL-4)（所有P<0.05) 和紧密连接 (TJ) 蛋白 (zonula occluden-1 (ZO-1) 的表达。LHFM 和 Cit_LHFM 提高了存活率（均 P<0.05）。特别是 Cit_LHFM 对 DSS 引起的损伤具有更大的保护作用。 , 特别是在改善结肠通透性、TJ 蛋白 (ZO-1、occludin 和 claudin-1) 的表达和分布以及降低 IL-4 和 IL-17 的表达方面(均P <0.05)。和瓜氨酸在保护 DSS 诱导的结肠炎损伤方面具有显着的协同作用，因此，富含瓜氨酸的瑞士乳杆菌发酵乳被认为是治疗 IBD 的潜在疗法。