蚊子為啥只咬你？

世界上有超過3000種不同類別的蚊子。

Yet, perhaps surprisingly, only a fraction of them actually feed on human beings - and, even when they do, they discriminate when choosing who's their next meal.

或許會令你感到驚訝的是，其中只有很少一部分會吸人血。而且，即使是那些會吸人血的蚊子，在選擇目標(biāo)時也會挑食。

Some people end up covered in bites, while others escape with only a nibble or two. So why does this happen? And what factors might influence the mosquito’s choice?

有些人渾身瘙癢，另一些人身上卻只有一兩個包。那么為什么會這樣呢?哪些因素會影響蚊子的口味呢?

Here, as detailed in The Conversation, Richard Halfpenny, a lecturer in biological sciences at Staffordshire University, explains what makes us worth biting.

來自斯塔福德郡大學(xué)的生物科學(xué)講師Richard Halfpenny為我們揭曉了答案。

The human skin’s microbiota

人體皮膚上的微生物群

The best evidence for what motivates a mosquito’s choice between different people is the variation in our skin microbiota.

蚊子出于什么動機(jī)才會不同人群中做出選擇呢?最佳答案為：我們皮膚上微生物群的變化。

We have an estimated 1m bacteria per square cm of skin, often comprising hundreds of species.

據(jù)估計(jì)，人體每平方厘米皮膚上擁有100萬個細(xì)菌，且通常包括數(shù)百個種類。

The odour this emits from our pores and hair follicles is the critical factor in telling mosquitoes how tasty we’d be.

而從毛孔與毛囊中所散發(fā)的氣味，是告訴蚊子我們有多么美味的關(guān)鍵因素。

In other words, mosquitoes don't select somebody for their inner biology, but rather for the micro-organisms that live on their skin.

換句話說，蚊子的口味其實(shí)并不會取決于人體內(nèi)部，而是取決于生活在我們皮膚上的微生物。

The composition of our skin microbiota mostly depends on our environment – what we eat and where we live.

我們的皮膚上微生物群的成分主要取決于我們的環(huán)境：我們吃什么與我們住在哪里。

Everything we touch, eat, drink and wash with has the potential to introduce new microbes, but genetic variation is also thought to affect how hospitable our skin is to the various species of microbes.

我們碰、吃、喝、洗的所有東西，都有可能在皮膚上引入新的微生物。此外，遺傳變異也會影響我們的皮膚對各種微生物的好客度。

This may be through genetically controlled production of proteins in the skin that act as barriers and prevent microbes from establishing and growing on the skin, or through more mundane aspects such as a person’s tendency to sweat or how oily their skin is.

比如說，我們可以通過基因控制皮膚上的蛋白質(zhì)生產(chǎn)，而這些蛋白質(zhì)可作為一道屏障，從而阻止微生物的停留與繁殖。再或者說，人體的出汗傾向與皮膚油性，也會影響微生物群的組成。

It’s worth remembering that, as pure sweat has no discernible odour, sweating itself may not be responsible for attracting mosquitoes.

值得記住的是，由于純凈的汗水沒有可辨別的氣味，因此出汗本身可能并不是吸引蚊子的原因。