酸奶酪真的是全能消化剂吗？

Remember the days when choosing a brand of yogourt was all about whether or not you preferred strawberry or liked your fruit on the bottom? Now, with seemingly endless health-related claims, it might feel as if it takes a doctorate to make the right choice at the dairy cooler. And what do bacterial cultures in yogourt have to do with your health? In the last of our series on probiotics, we’ll look at the role so-called good bacteria play in the world of yogourt.
还记得以前按照是否喜欢草莓口味或者是否喜欢酸奶底下水果来选择酸奶酪的品牌吗？现在，似乎什么都要和健康联系起来，以致在选择冷藏奶制品的时候恨不得都拿个博士学位来保证自己的选择正确性。你知道酸奶酪中的细菌培养和你的健康有着什么关联吗？在我们系列话题的最后，我们将着重讨论一下所谓的益生菌在酸奶酪中所扮演的角色。

A BIT ABOUT YOGOURT
关于酸奶酪
When milk - be it from a cow or goat, or even soy - is heated, cooled and inoculated with bacteria, most commonly Lactobacillus bulgaricus and/or Streptococcus thermophilus, the lactose sugar present in milk is broken down by the bacteria and converted to lactic acid. The result is yogourt: a slightly sour or even bitter tasting fermented product that is lower in lactose than milk, and is therefore better tolerated by individuals suffering from lactose intolerance. As you are likely aware, most yogourts are made with added fruit - and extra sugar or sweeteners along with it - to improve the taste.
当从奶牛、山羊甚至大豆中获得的乳液经过加热、冷藏并加入最常用的保加利亚乳酸杆菌或者嗜热链球菌等细菌之后，牛奶中的乳糖会被细菌转化成乳酸，从而产生了酸奶酪，一种轻微发酵的，有时口味微苦的，比牛奶乳糖含量低的乳制品，因此对于那些不宜摄入过多乳糖的个体来说它比牛奶更有优势。众所周知，大多数的酸奶酪中都会添加水果或糖类或甜味素，这些都能进一步提升它的口味。

WHAT ABOUT BACTERIA?
关于细菌
Because the nature of yogourt itself comes from the fermentation, much has been made of the role the bacteria play in yogourt’s relatively unique properties. In recent years, growing interest in the world of probiotics, or so-called good bacteria, has turned yogourt into a veritable superfood
由于酸奶酪是发酵而来的，其特殊的性质和其中的细菌密切相关。近年来，人们越来越关注益生菌，酸奶酪也被人们视为一种真正意义上的superfood。

But is the hype justified? At its simplest, you could say that yogourt is definitely a great choice; after all, it is a highly nutritious food even without the bacterial cultures. Aside from the change to the flavour and texture that occurs with fermentation, yogourt retains the primary nutrients associated with milk, including protein, calcium and B vitamins such as riboflavin (vitamin B2) and vitamin B12. The fat content varies according to the type of milk used, with some Balkan-style yogourts containing up to 8% milk fat. Some yogourts in Canada contain added vitamin D, usually around 100 IU (international units) per serving.
然而这些评价完全公平吗？最直接的说，酸奶酪确实是一种很好的选择，毕竟及时没有益生菌，它还是一种富有营养的食物。不考虑发酵所产生的口感及滋味上的改变，酸奶酪仍然保留了原材料牛奶中的主要营养成分，包括蛋白质、钙、B族维生素（维生素B2及维生素B12）。其中的脂肪含量依据所采用的牛奶种类不同而改变，一些Balkan型酸奶酪含有高于8%的脂肪。加拿大的一些酸奶酪还含有添加维生素D，通常每份在100IU水平左右。

But does the bacteria elevate yogourt’s nutritional status any higher than, say, regular milk? If you ask the makers of the various probiotic-rich yogourts, they would have you believe that their unique cocktails of bacteria offer specific health benefits, often related to digestive health or immune system function. But that’s where things get murky: When it comes to research on humans, most strains of probiotics have been subjected to few or no studies, leaving us to speculate on benefit based on rat or test-tube studies at best.
但是益生菌真的能毫无例外地提高酸奶酪的营养水平吗？如果你询问富益生菌酸奶酪生产商，他们会努力使你相信他们研制的独一无二的益生菌配方具有消化或免疫方面的特殊生理活性。但是使我们感到困惑的是：人类益生菌的活性测试往往缺少甚至没有，人们往往只能从小鼠或体外试管实验的结果来推测其在人体内的作用效果。

Among the brand leaders, perhaps the best-researched is Danone’s Activia yogourt. Made with a probiotic known as Bifidobacterium lactis regularis (or B.L. Regularis), the manufacturers claim that the bacteria not only passes intact through the digestive tract (an issue for some strains of bacteria, rendering them inactive by the time they reach the bowel), but that it can improve digestive health.
在品牌领先者中，得到最全面研究的要数达能的活性酸奶酪，它由双歧杆菌属B.L. Regularis发酵而得，它不仅能作用于整个消化道还能促进消化健康。

In fact, one double-blinded, randomized controlled trial showed that B.L. Regularis sped transit time in the gut of women who consumed three 125g servings of yogourt per day - which basically means that it made their bowels work faster. Similar trials on the elderly have also produced positive results using one or two servings of yogourt per day. This is potentially good news for those suffering from constipation, but some individuals may find increased bloating or flatulence, especially from the varieties with added fibre.
随机对照实验指出，妇女每天饮用三份每份125g的酸奶酪能加快肠蠕动，针对老年人群的类似实验中如果每天饮用两份的酸奶酪也能加快肠道循环。这个结果让便秘患者听到了福音，但是有些个体会出现胃气胀，特别当酸奶酪中添加了多种的纤维。

Yoplait suggests their Yoptimal yogourt improves immune system functioning through the addition of BB-12 Bifidobacterium and LA-5 Lactobacillus acidophilus (note that all yogourts contain at least some bacteria as part of the fermentation process; for our purposes, we are focusing on extra probiotics added by manufacturers). The manufacturers claim that at least a billion active cultures are present upon expiration, which is significantly higher than regular yogourts that might contain only a few hundred million bacteria (our digestive system contains more than a trillion total bacteria by comparison). The evidence for improved immune system function, however, is indirect, and largely taken from studies that have shown benefits for very specific populations.
Yoplait公司的酸奶酪产品通过添加BB-12双歧杆菌及LA-5乳酸杆菌来提高其免疫功能。厂家声称他们的酸奶酪在保质期内至少含有十亿单位的活性菌，而常规的酸奶酪仅仅含有几百万单位的活性菌（人类的消化系统共含有百万兆单位的活性菌）。关于其产品提高免疫能力活性的证据是间接的，主要来自于对特定人群的研究测试结果。

THE BOTTOM LINE
必须面对的现实
When it comes to yogourt, there is little doubt that a) yogourt is a nutritious food, even without the extra probiotics, and b) based on a cumulative body of research, probiotics seem beneficial, at least in certain circumstances, such as diarrhea caused by antibiotic use or lactose intolerance. But are we far enough along to say that yogourts that contain proprietary strains of probiotics will offer a large percentage of the population health benefits when consumed on a daily basis? It’s simply too soon to tell.
提到酸奶酪，我们可以肯定的是：1)它是一种富含营养的食物,及时不添加益生菌,2)由先前的研究可知,在特定的条件下,比如抗生素以及乳糖不耐受导致的腹泻时，益生菌对人体是有益的。但是仅凭这些就将含益生菌的酸奶酪看做是对大多数人群都有用的全能营养物质还为时过早。

- Jennifer Sygo is a dietitian in private practice at Cleveland Clinic Canada (clevelandcliniccanada.com), which offers executive physicals, prevention and wellness counselling and personal health care management in Toronto.
Translated by jiaxian