科学家制造出一种可以让人变得苗条的特殊细菌

  微生物或许会引发新一代的饮食热潮，近日，在举办的美国化学学会会议上，来自范德堡大学的研究者就表示，他们对细菌进行了程序化操作来使其可以产生特殊的分子，这种分子可以通过正常的代谢变成抑制饥饿的脂质，饮用含有这种重编程细菌的水的小鼠会吃得较少，机体脂肪含量下降而且也会抑制糖尿病的发生，甚至对其进行高脂肪饮食时依然如此，因此本文研究或许是一些减肥人士的关注重点。

  肥胖会明显增加个体患多种疾病的风险，比如心脏病、中风、2型糖尿病及某些癌症等；三分之一的美国人都是肥胖个体，而且追踪肥胖的起源也非常困难，生活方式的改变及适度用药仅会微小地减轻机体体重，而且很多人会出现反弹的现象；近些年来大量研究都表明，生活在机体肠道中的微生物群体或许是决定个体肥胖及患相关疾病风险的决定性因子，这就表明改变肠道微生物组或许会影响人类的健康。

  文章中，研究者选择了一种名为N-酰基-磷脂酰乙醇胺（NAPEs）的分子来作为治疗性分子，其是在餐后小肠中产生的一种分子，可以迅速转化为N-酰基-乙醇胺(NAEs)，即潜在的抑制食欲的脂质；研究者通过改变一系列益生菌的基因使其产生NAPEs，随后研究者将产生NAPEs的细菌加入到水中让小鼠饮用，同时给小鼠以高脂肪饮食喂养，这种饮食方式会使得小鼠发生肥胖，出现糖尿病和脂肪肝的迹象。

  研究者表示，相比摄入净水或包含未进行重编程细菌的水的小鼠，摄入含有产NAPE细菌的水的小鼠在治疗的8周里体重减轻了15%，另外小鼠的肝脏和血糖代谢相比对照小鼠也发生了明显的增强，接受治疗性细菌的小鼠同时也会保持较轻的体重和苗条的“身材”。在后期的实验中，研究者发现，小鼠机体中如果缺失从NAPEs制造NAEs的酶类，那么其或许并不会受益于产NAPEs的细菌的帮助，但给予制造NAE的细菌就可以克服这种问题。

  研究者表示，后期我们或许会利用制造NAE的细菌来进行最终的临床试验，目前主要的障碍就是开启人类试验或许具有一定的风险，即治疗的病人仅能通过粪便接触来将这种特殊细菌转移到另外个体中去，研究者希望通过更为深入的研究来开发出更为简便安全的方法来改善这种疗法，使其可以尽快进入临床治疗中。 （转化医学网360zhyx.com）

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The team will describe their approach at the 249th National Meeting & Exposition of the American Chemical Society (ACS).

Obesity strongly increases the risk for developing several diseases and conditions, such as heart disease, stroke, type 2 diabetes and some types of cancer. One in three Americans is obese, and efforts to stem the epidemic have largely failed. Lifestyle changes and medication typically achieve only modest weight loss, and most people regain the weight. In recent years, numerous studies have shown that the population of microbes living in the gut may be a key factor in determining the risk for obesity and related diseases, suggesting that strategically altering the gut microbiome may impact human health.

One advantage to microbial medicine would be that it's low maintenance, says Sean Davies, Ph.D. His goal is to produce therapeutic bacteria that live in the gut for six months or a year, providing sustained drug delivery. This is in contrast to weight-loss drugs that typically need to be taken at least daily, and people tend not to take their medications as directed over time. "So we need strategies that deliver the drug without requiring the patient to remember to take their pills every few hours," Davies says.

For a therapeutic molecule, Davies and colleagues at Vanderbilt University selected N-acyl-phosphatidylethanolamines (NAPEs), which are produced in the small intestine after a meal and are quickly converted into N-acyl-ethanolamines (NAEs), potent appetite-suppressing lipids. The researchers altered the genes of a strain of probiotic bacteria so it would make NAPEs. Then they added the bacteria to the drinking water of a strain of mice that, fed a high-fat diet, develop obesity, signs of diabetes and fatty livers.

Compared to mice who received plain water or water containing control, non-programmed bacteria, the mice drinking the NAPE-making bacteria gained 15 percent less weight over the eight weeks of treatment. In addition, their livers and glucose metabolism were better than in the control mice. The mice that received the therapeutic bacteria remained lighter and leaner than control mice for up to 12 weeks after treatment ended......