根据新华社东京7月11日报道，人体肠道内充满细菌，其中的有益细菌有助食物消化。日本研究人员的一项新发现显示，肠道内还有17种细菌能帮助人体调节失衡的免疫功能，防止出现炎症。
东京大学教授服部正平等领导的研究小组对调节体内免疫反应的“调节T细胞”进行了研究。该小组在新一期英国学术期刊《自然》上报告说，“调节T细胞”属免疫细胞中的淋巴细胞，为研究能增加“调节T细胞”的细菌，他们反复向在无菌状态下饲养的实验鼠体内注入健康人的肠道物质，最终发现17种能调节免疫反应的细菌。
据介绍，这些细菌都属于能形成芽孢、厌氧生长的革兰氏阳性大杆菌。研究人员将这些细菌注入实验鼠体内后，实验鼠的腹泻和肠炎都痊愈了。
研究小组还发现，在与免疫功能失衡相关的溃疡性大肠炎患者的肠道内，上述细菌多数都减少了。研究小组认为，通过投放细菌，有可能治愈上述疾病。
目前，一些国家的医疗机构正尝试向肠炎和相关感染患者体内注入健康人的肠道物质，以重新实现肠内细菌平衡，但这种治疗会同时注入没有治疗意义的细菌。有业界专家评论指出，如果这个研究小组的实验能确定可治疗肠炎的细菌种类，将有助开发出安全且有效的治疗方法。（生物谷Bioon.com）
生物谷推荐的英文摘要
Nature doi:10.1038/nature12331
T induction by a rationally selected mixture of Clostridia strains from the human microbiota
Koji Atarashi, Takeshi Tanoue, Kenshiro Oshima, Wataru Suda, Yuji Nagano, Hiroyoshi Nishikawa, Shinji Fukuda, Takuro Saito, Seiko Narushima, Koji Hase, Sangwan Kim, Joëlle V. Fritz, Paul Wilmes, Satoshi Ueha, Kouji Matsushima, Hiroshi Ohno, Bernat Olle, Shimon Sakaguchi, Tadatsugu Taniguchi, Hidetoshi Morita, Masahira Hattori & Kenya Honda
Manipulation of the gut microbiota holds great promise for the treatment of inflammatory and allergic diseases1, 2. Although numerous probiotic microorganisms have been identified3, there remains a compelling need to discover organisms that elicit more robust therapeutic responses, are compatible with the host, and can affect a specific arm of the host immune system in a well-controlled, physiological manner. Here we use a rational approach to isolate CD4+FOXP3+ regulatory T (Treg)-cell-inducing bacterial strains from the human indigenous microbiota. Starting with a healthy human faecal sample, a sequence of selection steps was applied to obtain mice colonized with human microbiota enriched in Treg-cell-inducing species. From these mice, we isolated and selected 17 strains of bacteria on the basis of their high potency in enhancing Treg cell abundance and inducing important anti-inflammatory molecules—including interleukin-10 (IL-) and inducible T-cell co-stimulator (ICOS)—in Treg cells upon inoculation into germ-free mice. Genome sequencing revealed that the 17 strains fall within clusters IV, XIVa and XVIII of Clostridia, which lack prominent toxins and virulence factors. The 17 strains act as a community to provide bacterial antigens and a TGF-β-rich environment to help expansion and differentiation of Treg cells. Oral administration of the combination of 17 strains to adult mice attenuated disease in models of colitis and allergic diarrhoea. Use of the isolated strains may allow for tailored therapeutic manipulation of human immune disorders.
