What causes bad breath? - Mel Rosenberg

翻译人员: Kristie Leung 校对人员: Claire Zhang

There is a curse that has plagued humanity since ancient times.

自古以来，人类一直被一个咀咒缠绕。

The Greeks fought it by chewing aromatic resins,

古希腊人以咀嚼有芳香的树脂对抗它，

while the Chinese resorted to egg shells.

而中国人则依靠蛋壳。

In the ancient Jewish Talmud,

在古犹太教的《塔木德》文献，

it's even considered legal grounds for divorce.

它甚至是合法离婚的一个条件。

This horrible scourge is halitosis, otherwise known as bad breath.

这个可怕的灾祸就是口臭。

But what causes it, and why is it so universally terrifying?

但它是怎么样来的？为什么它被所有人害怕着呢？

Well, think of some of the worst odors you can imagine,

那么想像一下世界上你觉得最臭的气味，

like garbage, feces or rotting meat.

例如垃圾、粪便或者腐烂的肉。

All of these smells come from the activity of microorganisms,

所有的这些气味来自微生物的活动，

particularly bacteria,

特别是细菌，

and, as disgusting as it may sound,

虽然听起来不能再恶心，

similar bacteria live in the moisture-rich environment of your mouth.

跟那些相似的细菌正住在你湿润的口腔里。

Don't panic.

不要慌张。

The presence of bacteria in your body is not only normal,

你身体里有细菌不但是再正常不过的事，

it's actually vital for all sorts of things,

它们其实在很多方面上都必不可缺，

like digestion and disease prevention.

比如消化和预防疾病。

But like all living things, bacteria need to eat.

但跟其他生物一样，细菌也需要食物。

The bacteria in your mouth feed off of mucus,

在你口里的细菌以吃黏液、

food remnants,

食物残渣

and dead tissue cells.

和死的组织细胞生存。

In order to absorb nutrients through their cell membranes,

为了从细胞膜吸收养分，

they must break down the organic matter into much smaller molecules.

它们必须将有机物质变成小一点的分子。

For example, they'll break proteins into their component amino acids

例如，它们会把蛋白质打碎成它的要素胺基酸，

and then break those down even further into various compounds.

然后再把它们变成更小的其他化合物。

Some of the foul-smelling byproducts of these reactions,

有些从这个反应产生的臭的副产品，

such as hydrogen sulfide and cadaverine,

像硫化氢和尸胺，

escape into the air

逃被释放到大气里

and waft their way towards unsuspecting noses.

然后飘到没有毫无防备预备的鼻子里。

Our sensitivity to these odors and interpretation of them as bad smells

我们对这些味道的敏感度和辨别为臭味的举动

may be an evolutionary mechanism warning us of rotten food

可能是一种进化的途径来警告我们有腐烂的食物

and the presence of disease.

和疾病。

Smell is one of our most intimate and primal senses,

气味是我们其中一个最本质和原始的感官，

playing a huge role in our attraction to potential mates.

而它是未来伴侣的吸引中非常重要。

In one poll, 59% of men and 70% of women

投票显示，59%的男人和70%的女人

said they wouldn't go on a date with someone who has bad breath,

说他们不会跟一个有口臭的人约会，

which may be why Americans alone

那这就可以解释为什么美国人民

spend $1 billion a year on various breath products.

可以用上一亿美元来买不同的口臭产品。

Fortunately, most bad breath is easily treated.

幸运的是，大部分的口臭都能容易地解决。

The worst smelling byproducts come from gram-negative bacteria

最臭的副产品来自格兰仕阴性的细菌，

that live in the spaces between gums and teeth

它们住在牙床和牙齿之间的空隙

and on the back of the tongue.

和舌头的底下。

By brushing and flossing our teeth,

刷牙和用牙线清洁牙齿、

using antibacterial mouthwash at bedtime,

睡觉前用抗菌的嗽口水、

gently cleaning the back of the tongue with a plastic scraper

用塑胶刮片轻轻地清洁舌头的底下

and even just eating a healthy breakfast,

和甚至只吃一个健康的早餐，

we can remove many of these bacteria and their food sources.

我们可以除去很多这种细菌和它们的食物来源

In some cases, these measures may not be enough

在某些情况，这些措施可能还不够

due to dental problems, nasal conditions, or rarer ailments,

因为牙齿问题、鼻子的情况或者旱见的病，

such as liver disease and uncontrolled diabetes.

像肝病和没被控制的糖尿病。

Behaviors like smoking and excessive alcohol consumption

生活习惯，例如吸烟和酗酒

also have a very recognizable odor.

都会有一股非常容易分辨的气味。

Regardless of cause,

无论什么原因，

the bad smell almost always originates in the mouth

臭味差不多都是来自于口腔

and not the stomach or elsewhere in the body.

而不是胃或身体的其他部分。

But one of the biggest challenges lies

可是其中一个最大的挑战就在

in actually determining how our breath smells in the first place,

实际决定我们的口气怎样变臭，

and it's unclear why.

还有为什么。

It may be that we're too acclimatized

可能我们对自己口里的气味太习惯了

to the smell inside our own mouths to judge it.

所以才不能判断。

And methods like cupping your hands over your mouth,

方法像把手盖在口上，

or licking and smelling your wrist don't work perfectly either.

或者舔然后闻你的手腕都不怎么有效。

One study showed that even when people do this,

研究显示即使人们这样做，

they tend to rate the smell subjectively

它们倾向于主观地

according to how bad they thought it was going to be.

根据他们自己想像中气味来评价那气味

But there's one simple, if socially difficult,

但是有一种简单的，但是在社交场合中很困难的

way of finding out how your breath smells:

方法来知道你的口气闻起来怎样：

just take a deep breath and ask a friend.

只要深呼吸然后问你的朋友。