Breton Jérôme, Plé Coline, Guerin-Deremaux Laetitia, Pot Bruno, Lefranc-Millot Catherine, Wils Daniel, Foligné Benoit
Bactéries Lactiques & Immunité des Muqueuses, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, U1019, UMR8204, Université Lille Nord de France, 1 rue du Pr Calmette, BP 245, 59019 Lille Cedex, France.
Roquette Nutritional Sciences, Roquette, 62080 Lestrem, France.
Biomed Res Int. 2015;2015:162398. doi: 10.1155/2015/162398. Epub 2015 Apr 21.
The beneficial effects of carbohydrate-derived fibers are mainly attributed to modulation of the microbiota, increased colonic fermentation, and the production of short-chain fatty acids. We studied the direct immune responses to alimentary fibers in in vitro and in vivo models. Firstly, we evaluated the immunomodulation induced by nine different types of low-digestible fibers on human peripheral blood mononuclear cells. None of the fibers tested induced cytokine production in baseline conditions. However, only one from all fibers almost completely inhibited the production of anti- and proinflammatory cytokines induced by bacteria. Secondly, the impact of short- (five days) and long-term (three weeks) oral treatments with selected fibers was assessed in the trinitrobenzene-sulfonic acid colitis model in mice. The immunosuppressive fiber significantly reduced levels of inflammatory markers over both treatment periods, whereas a nonimmunomodulatory fiber had no effect. The two fibers did not differ in terms of the observed fermentation products and colonic microbiota after three weeks of treatment, suggesting that the anti-inflammatory action was not related to prebiotic properties. Hence, we observed a direct effect of a specific fiber on the murine immune system. This intrinsic, fiber-dependent immunomodulatory potential may extend prebiotic-mediated protection in inflammatory bowel disease.
碳水化合物衍生纤维的有益作用主要归因于对微生物群的调节、结肠发酵增加以及短链脂肪酸的产生。我们在体外和体内模型中研究了对膳食纤维的直接免疫反应。首先，我们评估了九种不同类型的低消化性纤维对人外周血单核细胞的免疫调节作用。在基线条件下，所测试的纤维均未诱导细胞因子产生。然而，所有纤维中只有一种几乎完全抑制了细菌诱导的抗炎和促炎细胞因子的产生。其次，在小鼠三硝基苯磺酸结肠炎模型中评估了短期（五天）和长期（三周）口服选定纤维的影响。在两个治疗期内，具有免疫抑制作用的纤维均显著降低了炎症标志物水平，而无免疫调节作用的纤维则无效果。治疗三周后，这两种纤维在观察到的发酵产物和结肠微生物群方面没有差异，这表明抗炎作用与益生元特性无关。因此，我们观察到一种特定纤维对小鼠免疫系统有直接作用。这种内在的、纤维依赖性的免疫调节潜力可能会扩展益生元介导的对炎症性肠病的保护作用。
