科学美国人60秒 SSS 不知吃么什 那由微生物来决定吧~（在线收听）

Gut Microbes Help Keep Starved Flies Fecund 不知吃么什 那由微生物来决定吧~

Just like humans, fruit flies have to eat a balanced diet.

果蝇和人类一样,也要饮食均衡.

"They need sugar to survive, they need amino acids to make eggs, to have stem cells proliferate. They need salt, they need vitamins."

他们需要糖类生存,氨基酸用于产卵,干细胞用于增值.它们需要盐分.需要维生素。

Carlos Ribeiro, a neuroscientist at the Champalimaud Center in Portugal. Yeast, he says, is a crucial component of the fly diet. "I always say, yeast is the steak of the fly."

Carlos Ribeiro是葡萄牙Champalimaud 中心的神经科学家。酵母，是苍蝇饮食中重要的一部分。“我总是说，酵母就相当于苍蝇的牛排。”

Take yeast away, and the flies crave it—gotta make those eggs. Ribeiro and his team found they could also elicit that yearning for yeast simply by removing a few key amino acids from the flies' diet—but only in those flies that had their gut microbiome wiped out.

将酵母拿走，苍蝇渴望利用酵母来产卵。Ribeiro和研究团队发现，只需要移除苍蝇饮食中的几种关键的氨基酸，就可以消除苍蝇的这种渴望——但是以上只适用于体内的肠胃微生物消灭的苍蝇。

Here’s the twist: when Ribeiro and his colleagues restored the standard fly gut microbiome, amino-acid-deprived flies did not seek out yeast to compensate. That might seem like the gut microbes are actually working against the flies' best interest—blocking their instincts to seek out missing nutrients.

但是令人纠结的事情出现了：当Ribeiro和同事们恢复了苍蝇体内的肠道微生物，被去除氨基酸的苍蝇并没有来寻找酵母进行补偿。可能是肠道微生物会作用于果蝇的最佳利益——阻止果蝇的本能去寻找丢失的营养。

But what actually happened, Ribeiro says, is that flies with the gut microbes maintained good egg production despite their nutritional deficiency. Suggesting that somehow, microbes help the flies adapt to nutrient-poor conditions.

但是到底发生了什么，Ribeio表示，尽管营养缺失，果蝇和肠道微生物可以保持果蝇产卵良好。这在某种程度上表明。微生物帮助了果蝇适应了营养匮乏的环境。

"So somehow the microbes reprogram the metabolism of the fly to now cope better with an absence of amino acids in the diet. And that might also lead then to the fly not having to produce a strong craving for amino acids." The study is in the journal PLoS Biology.

所以，在某种程度上，微生物可以调节果蝇的新城代谢使其更好地应对氨基酸缺乏的饮食。这可能也导致果蝇不会产生对氨基酸那么强烈的渴望。该项研究成果发表在《公共科学图书馆生物学》杂志上。

Of course, flies are not humans. But still, Ribeiro says, "I think there is now more and more compelling evidence that the microbes in the gut, also of humans, affect behavior, mood and stress, and maybe even, people propose, some diseases. But how microbes do so and why they would do so is completely unclear."

当然，果蝇不是人类。但是Ribeiro表示，“我认为有更多的证据表明，肠道微生物，其中包括人类的肠道微生物，会影响行为、情绪、和压力。甚至人们认为会影响一些疾病。”但是我们完全不清楚这些微生物的作用机理以及它们这么做的原因。

Still: next time you're staring at a menu, undecided on what to order…you might try just going with your gut.

下一次，你盯着菜单不知道点什么的时候，或许可有跟着肠道的感觉走~