背景介绍：
长期以来，科学家和公司致力于研发人造母乳以替代真实的母乳喂养，但成果有限。早期配方奶粉的营养成分与母乳相比有较大差距，且仅能满足部分营养需求。随着对母乳成分研究的深入，人们发现母乳中的独特成分如人乳低聚糖（HMOs）对婴儿健康至关重要。然而，并非所有新生儿都能享受母乳喂养，社会对高品质配方奶粉的需求依然强烈。近年来，配方奶粉制造商在 HMOs 和人乳蛋白等关键成分上取得了重要突破，但仍需进一步的技术创新。
Baby formulas now share some
ingredients with breast milk
如今的婴儿配方奶粉也具有母乳的一些成分
They may one day replicate its
benefits
也许有一天它们能复刻母乳的益处
For more than 100 years scientists and companies have tried to create an
artificial version of breast milk. Success has been limited. Early efforts,
full of sugar or cheap corn syrup, fell woefully short. Even 20th-century
formulas meant to
emulate
breast milk’s nutritional profile were a far cry from
the real thing.
一百多年来，科学家和公司一直试图生产出人造母乳，但取得的成功却相当有限。早期的努力，主要集中在添加大量糖或廉价的玉米糖浆，然而这些尝试所带来的改善并不明显。即便是20世纪那些旨在精确模仿母乳营养特征的配方奶粉，与真实的母乳相比，仍然存在着显著的差距。
Breast milk is, scientists now know, made of unique human proteins, sugars
and fats, capable of delivering not only nutrition but also a boost to a baby’s
immune system. Yet not all newborns have access to it.
Only about a quarter of American babies are exclusively breastfed for their first six months, the standard recommendation from health officials.
科学家现已明确，母乳是由一系列独特的人类蛋白质、糖和脂肪构成的复杂混合物。它不仅能够为婴儿提供必要的营养，还能显著增强婴儿的免疫系统。然而，现实情况却是，并非所有新生儿都能享受到母乳喂养的益处。
按照卫生官员的标准建议，仅有大约25%的美国婴儿能在出生后六个月内完全接受母乳喂养。
In Canada the figure is below 40%. The reasons are various. Some mothers find it prohibitively painful; others worry about being able to produce enough milk; and some children are born into families with no parents capable of breastfeeding. The need for infant formula, which today offers a safe and nutritious alternative, remains.
在加拿大，这一比例更是低于40%。造成这一现象的原因多种多样：有的母亲因哺乳带来的疼痛而退缩；有的则担心自己的母乳产量不足；还有的婴儿则出生在无法提供母乳喂养条件的家庭中。尽管如今婴儿配方奶粉已成为一种安全且营养的替代品，但社会对更高品质配方奶粉的需求依然强烈。
So, too, does the incentive for formula-makers to find a better recipe.
Recently they seem to have made important headway. Some formulas now contain
carbohydrates previously unique to human milk; human proteins and lipids may
soon follow. If progress continues, bottle-fed children may eventually enjoy
some of the advantages of breast milk that they have hitherto missed out on.
随着需求的增长，配方奶粉制造商在寻找更好配方的道路上也加大了投入。最近，他们似乎取得了重要的突破。现在，一些配方奶粉中已经包含了以往仅在人乳中特有的碳水化合物；而人类蛋白质和脂质也可能很快就会出现在这些配方中。如果这一趋势能够持续，那么奶瓶喂养的儿童最终或许能够享受到他们迄今为止所错过的母乳的某些独特优势。
Among the most important constituents of breast milk are human milk
oligosaccharides (HMOs), a group of around 200 indigestible carbohydrates
unique to humans. Once in the gut, they protect against harmful microbes, which
mistake them for sugars on gut cells and bind to them instead of infecting the
body.
母乳中最重要的成分之一是人乳低聚糖（HMOs），这是一组包含约200种人类特有的不可消化碳水化合物的复杂混合物。一旦进入婴儿的肠道，它们就能有效防止有害微生物的侵害。这些有害微生物会误将 HMOs 当作肠道细胞上的糖并与之结合，从而避免了感染身体的风险。
They also nourish beneficial bacteria and encourage them to colonise the gut. Scientists have long known that babies fed breast milk have healthier microbiomes thanks to HMOs and, depending on the mix in their mother’s milk, less
diarrhoea
.
同时，HMOs 还能滋养有益细菌，并促使它们在肠道中定居。科学家们早已知晓，由于 HMOs 的存在，母乳喂养的婴儿拥有更加健康的微生物群，并且根据母乳中 HMOs 的混合物不同，婴儿的腹泻情况也会相应减少。
Formula-makers launched their first HMO recipe in 2016, after years of
struggling to make the sugars at scale. Instead of troublesome chemical
synthesis, they turned to microbial cell factories, in which vats of
genetically tweaked bacteria turn lactose, a common milk sugar, into HMOs.
Studies on the first HMO formulas, which contained only one or two of these
carbohydrates, reported few compelling benefits.
经过多年的努力，配方制造商终于在2016年推出了他们的第一个 HMO 配方。这一次，他们没有采用复杂的化学合成方法，而是转向了微生物细胞工厂。在这些工厂中，大桶的基因调整细菌被转化为能够生产乳糖（一种常见的牛奶糖）的工厂，并在此基础上加入了 HMO。然而，对第一批 HMO 配方的研究显示，它们仅包含一两种这些碳水化合物，几乎没有令人信服的好处。
But manufacturers now seem to have hit their stride: recent studies (mostly by manufacturers themselves) indicate that formulas with five HMOs shift infants’ microbiome (and the frequency and consistency of their stool) closer to those of breastfed babies. Formulas with six HMOs are now becoming available to consumers in certain places, such as Hong Kong, and more are on the way.
但制造商似乎并未因此止步：最近的研究（主要是制造商自己进行的）表明，含有五种 HMO 的配方奶粉可以使婴儿的微生物群（以及大小便的频率和稠度）更接近母乳喂养婴儿的微生物群。目前，含有六种 HMO 的配方奶粉已在香港等某些地区向消费者提供，且更多配方奶粉正在紧锣密鼓地推出中。
Whatever their benefits, such formulas remain far simpler than the milk
breastfed babies receive, which contains dozens of HMOs. Because microbial cell
factories can make only the simplest sugars, says Birgitte Zeuner from the
Technical University of Denmark, reaching similar numbers in formula milk will
take new technology.
尽管这些配方奶粉在某些方面取得了进步，但它们仍然比母乳喂养的婴儿所接受的母乳要简单得多。母乳中含有几十种 HMO，而配方奶中的 HMO 种类却相对有限。丹麦技术大学的 Birgitte Zeuner 指出，由于微生物细胞工厂目前只能生产最简单的糖，因此要在配方奶中达到与母乳相似的 HMO 数量，还需要新的技术突破。
She is working with DSM-Firmenich, a manufacturer, to find enzymes that can combine simple sugars into longer, complex structures.
Photosynthesis, a natural sugar-building process, also holds promise. In June scientists led by Patrick Shih at the University of California in Berkeley engineered a tobacco-like plant to produce at least a dozen HMOs in its leaves.
她正在与制造商 DSM-Firmenich 合作，寻找能够将简单糖结合成更长、更复杂结构的酶。
此外，光合作用作为一种天然的糖分生成过程，也展现出了巨大的潜力。今年6月，加州大学伯克利分校帕特里克·施领导的科学家团队成功改造了一种类似烟草的植物，使其叶子中能够产生至少12种 HMO。
Human milk proteins may also be making their way into formula. A New York
startup called Helaina uses gene-edited yeast to produce human lactoferrin. In
breast milk this protein is thought to help babies absorb iron and protect
against
nefarious
gut bacteria by stealing vital iron from them and poking
holes in their cell membranes. Helaina aims to reproduce this effect.
除了 HMOs 之外，人乳蛋白也可能成为未来配方奶粉的重要成分。纽约一家名为 Helaina 的初创公司正在使用基因编辑酵母生产人乳铁蛋白。在母乳中，这种蛋白质被认为可以帮助婴儿吸收铁，并通过窃取体内重要的铁并在细胞膜上戳出小孔洞来防止有害的肠道细菌入侵。Helaina 的目标就是复刻这种效果。
Adding lactoferrin from cow’s milk to formula has so far shown mixed results, but the human version possesses a subtly different structure which the company expects will help. Laura Katz, Helaina’s boss, says the company will start selling their lactoferrin this year, but initially for products for adults, who might also benefit from some of breast milk’s constituents.
到目前为止，将牛奶中的乳铁蛋白添加到配方奶粉中的尝试结果好坏参半，但人类母乳版本的乳铁蛋白结构略有不同，Helaina 公司希望这能够带来更好的效果。Helaina 的老板 Laura Katz 表示，该公司今年将开始销售乳铁蛋白产品，但最初是针对成人的。不过，他们相信这些产品也可能让成人从母乳的某些成分中受益。
重难点词汇
：
