Why do we pass gas? - Purna Kashyap

我們為甚麼會放屁? - Purna Kashyap

譯者: 以幸 張 審譯者: 瑞文Eleven 林Lim

[我們什麼會放屁？]

Flatulence, or passing gas, is a normal daily phenomenon.

脹氣，或放屁，是一種正常的日常現象。

Most individuals, yes, that includes you,

大多數人皆如此，也包括你

will make anywhere from 500-1500 milliliters of gas

會產生500-1500毫升氣體

and can pass gas ten to twenty times a day.

並且一天可以放屁十到二十次

But where does this bodily gas come from?

但是這些從體內排出的氣體從哪裡來?

A small proportion may come from ingesting air during sleep, or at other times,

一小部分可能來自於睡眠 或在其他時間攝入的空氣

but the majority of gas is produced by bacteria in our intestines

但大多數氣體由腸子中的細菌所產生

as they digest parts of food which we cannot.

因為它們會消化我們不能消化的食物

Our intestine is home to trillions of bacteria

我們的腸道是眾多細菌的家

living in a symbiotic relationship with us.

與我們共同生活

We provide them with a safe place to stay and food to eat.

我們為它們提供安全的處所及食物

In exchange, they help us extract energy from our food,

它們幫助我們從食物中 提取能量作為交換

make vitamins for us, like vitamin B and K, boost our immune system,

製造維生素增強我們的免疫系統， 例如維生素B和K ，

and play an important role in gastrointestinal barrier function,

並且在消化道屏障功能 (阻止病原進入人體)

motility and the development of various organ systems.

及各器官系統的運作、發展中 扮演很重要的角色

Clearly, it's in our best interest to keep these bacteria happy.

顯然的，讓這些細菌開心 符合我們的最佳利益

Gut bacteria get their nutrition primarily from undigested food,

腸道細菌主要由 未消化的食物得到所需的營養

such as carbohydrates and proteins, which come to the large intestine.

例如其中的碳水化合物 和蛋白質從大腸得到

They ferment this undigested food to produce a wide range of compounds,

它們發酵這些未消化的食物 以產生範圍廣泛的化合物

such as short-chain fatty acids and, of course, gases.

如短鏈脂肪酸，當然--還有氣體。

Hydrogen and carbon dioxide are the most common gaseous products

在細菌的發酵作用中， 氫和二氧化碳是最常見的氣體產物

of bacterial fermentation, and are odorless.

它們是沒有味道的

Some people also produce methane due to specific microbes present in their gut.

有些人的腸道由於有特定微生物的存在 所以他們還產生甲烷

But methane is actually odorless, too.

但是甲烷其實也是無味的

Well then, what stinks?

那麼，什麼東西這麼臭？

The foul smell is usually due to volatile sulfur compounds,

臭味一般是來自於揮發性硫化合物

such as hydrogen sulfide and methanethiol, or methyl mercaptan.

如硫化氫、甲基硫醇

These gases, however, constitute less than 1% of volume,

然而這些氣體總體積小於1％

and are often seen with ingestion of amino acids containing sulfur,

揮發性硫化合物 也常見於攝入的胺基酸中

which may explain the foul smell of gas from certain high protein diets.

這也許可以解釋某些惡臭氣體 從高蛋白飲食而來(蛋白質由胺基酸組成)

Increased passage of gas is commonly noticed after eating foods

通常在吃完後容易排氣的食物

with high amounts of indigestible carbohydrates,

多為大量難消化的碳水化合物

like beans, lentils, dairy products, onions, garlic, leeks, radishes,

如豆類、小扁豆、乳製品、 蔥、蒜、韭菜、蘿蔔

potatoes, oats, wheat, cauliflower, broccoli, cabbage, and brussel sprouts.

馬鈴薯、燕麥、小麥、花菜、 花椰菜、白菜及甘藍。

Humans lack the enzymes,

人體缺乏某些酶(酵素)，

so the bacteria able to ferment complex carbohydrates take over,

所以細菌接替發酵 複合式碳水化合物的工作

and this naturally leads to more gas than usual.

自然導致產生較多量的氣體

But if you feel uncomfortable, bloated or visibly distended,

但是如果你覺得不舒服或肚子發脹

this may indicate impaired movement of gas along the gastrointestinal track.

這可能表示氣體沿著腸胃道流動時受阻

It's important not to just blame certain foods

重要的是不要只指責某些食物

for gas and bloating and then avoid them.

為了排氣和腹脹而避之唯恐不及

You don't want to starve the bacteria that digest these complex carbohydrates,

你不會想餓死消化這些 複合式碳水化合物的細菌

or they'll have to start eating the sugars in the mucus lining of your intestines.

否則它們就必須開始吃 在你的腸道粘液內襯的糖。

Your personal gas will vary based on what you eat,

你的個人氣體會根據你吃什麼

and what bacteria are in your gut.

和腸道中細菌種類不同而有所區別

For example, from the same starting sugar,

舉例來說，從同樣的一口糖

the bacteria clostridium produces carbon dioxide, butyrate and hydrogen,

梭狀芽孢桿菌產生 二氧化碳、丁酸鹽和氫

while propionibacterium can produce carbon dioxide, propionate and acetate.

而丙酸桿菌可產生二氧化碳、 丙酸鹽和乙酸鹽

At the same time, methanogens can use hydrogen and carbon dioxide

同時，其他細菌可以利用氫和二氧化碳

produced by other bacteria to generate methane,

來產生甲烷

which can reduce the total volume of gas by using up hydrogen and carbon dioxide.

利用氫氣和二氧化碳 可以減少氣體的總體積

So there's a complex web among intestinal bacteria

所以這是在腸道細菌之間複雜的網絡

allowing them to flourish by either directly consuming undigested food,

細菌可以直接食用未消化的食物

or using what other bacteria produce.

或者利用其他的細菌來壯大自己

This interaction largely determines the amount and type of gas produced,

這種交互作用左右了 生成氣體的量和類型

so gas production is a sign that your gut bacteria are at work.

所以產生氣體代表 你的腸道細菌正常作用

But in some instances, people may develop abnormal increased flatulence.

但在某些情況下 人們或許會產生異常的胃腸脹氣

A common example is lactose intolerance.

一個常見的例子是乳糖不耐症

Most individuals have the enzyme for breaking down lactose,

大多數人都有酶來分解乳糖

a sugar present in milk and milk-derived products.

乳糖存在於牛奶中的糖和乳製產品中

But some people either lack it entirely, or have a reduced amount,

但有些人缺乏或只有少量這種酶

such as after a gastrointestinal infection,

如在胃腸道感染後

so they're unable to digest lactose products and may experience cramping,

使他們無法消化乳糖產品，也可能會腸胃痙攣

along with increased flatulence due to bacterial fermentation.

造成因細菌發酵而腸胃脹氣加劇

But remember, most gas is produced

但請記住，大部分的氣體

as a natural result of bacterial fermentation in the intestine,

是細菌在腸道內發酵的自然結果

and indicates healthy functioning of the gut.

並代表腸道很健康

The amount and type can vary based on your diet and the bacteria in your intestine.

數量和類型依你的飲食和腸道細菌而異

Exercise social courtesy while passing gas, and do try to forgive your bacteria.

當排氣時，注意禮節，並試著原諒你的細菌

They're only trying to be helpful.

它們只是試著對大家有所幫助！