法国国家健康与医学研究所10月21日宣布，他们与国家农艺研究所的科研人员通过共同研究发现，人体肠道菌群中一种细菌的缺失会导致人患上克罗恩氏病，这一发现将有助于开发针对这种病症的新疗法。
据该研究所介绍，克罗恩氏病，即节段性回肠炎，在欧美等国家比较常见，大约每1000人中就有一人患病，它会引起消化系统发炎，具体症状包括腹痛、腹泻、直肠出血、体重减轻和关节炎等。这种病往往难于确诊，因为它的症状与肠过敏和溃疡性结肠炎等其他肠病相似。
研究人员发现，在克罗恩氏病患者的肠道菌群中，一种名为“柔嫩梭菌群”严重缺乏，甚至数量几乎为零，而这个菌群中的主要细菌——F.Prausnitzii的缺失是造成这种状况的主要原因。科研人员认为，正是因为这种细菌数量过少导致了人体肠道免疫系统的紊乱，而且他们还发现，即使是接受了手术的克罗恩氏病患者，如果体内这种细菌的数量依然很低，那么其旧病复发的几率也会随之增高。
为了验证这种细菌的作用，科学家们在体外对这种细菌的细胞进行培养，发现它的分子果然具有抗炎症的特性，另外他们还向染病的实验鼠注射了含有这种细菌的药物，结果不但减轻了病鼠的炎症，还有效延长了它们的寿命。科研小组表示，鉴于这种细菌的特殊功能，它有望作为一种新的益生菌被添加到食品当中，同时，它也为开发治疗克罗恩氏病的药物提供了新的思路。相关论文发表在美国《国家科学院院刊》（PNAS）上。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS，doi: 10.1073/pnas.0804812105 ，Harry Sokol，Philippe Langella
Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients
Harry Sokol*,?, Bénédicte Pigneur?,?, Laurie Watterlot*, Omar Lakhdari*, Luis G. Bermúdez-Humarán*, Jean-Jacques Gratadoux*, Sébastien Blugeon*, Chantal Bridonneau*, Jean-Pierre Furet*, Gérard Corthier*, Corinne Grangette§, Nadia Vasquez?, Philippe Pochart?, Germain Trugnan?, Ginette Thomas?, Hervé M. Blottière*, Jo?l Doré*, Philippe Marteau‖, Philippe Seksik?,**,??, and Philippe Langella
A decrease in the abundance and biodiversity of intestinal bacteria within the dominant phylum Firmicutes has been observed repeatedly in Crohn disease (CD) patients. In this study, we determined the composition of the mucosa-associated microbiota of CD patients at the time of surgical resection and 6 months later using FISH analysis. We found that a reduction of a major member of Firmicutes, Faecalibacterium prausnitzii, is associated with a higher risk of postoperative recurrence of ileal CD. A lower proportion of F. prausnitzii on resected ileal Crohn mucosa also was associated with endoscopic recurrence at 6 months. To evaluate the immunomodulatory properties of F. prausnitzii we analyzed the anti-inflammatory effects of F. prausnitzii in both in vitro (cellular models) and in vivo [2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced] colitis in mice. In Caco-2 cells transfected with a reporter gene for NF-κB activity, F. prausnitzii had no effect on IL-1β-induced NF-κB activity, whereas the supernatant abolished it. In vitro peripheral blood mononuclear cell stimulation by F. prausnitzii led to significantly lower IL-12 and IFN-γ production levels and higher secretion of IL-10. Oral administration of either live F. prausnitzii or its supernatant markedly reduced the severity of TNBS colitis and tended to correct the dysbiosis associated with TNBS colitis, as demonstrated by real-time quantitative PCR (qPCR) analysis. F. prausnitzii exhibits anti-inflammatory effects on cellular and TNBS colitis models, partly due to secreted metabolites able to block NF-κB activation and IL-8 production. These results suggest that counterbalancing dysbiosis using F. prausnitzii as a probiotic is a promising strategy in CD treatment.
