He was fascinated by the question: Why do some belly buttons collect more lint than others?

這疑問使他著迷：為什麼有些人的肚臍會聚集比較多棉絨。

But no one knew the answer.

但沒有人知道答案。

So for three years he collected his own belly-button lint to find out.

所以三年來他持續收集自己肚臍裡的棉絨，試圖獲得解答。

And after interviewing friends and analyzing 503 of his own samples, Steinhauser discovered the culprit: stomach hair.

在訪問朋友並分析了 503 份自己的樣本後，Steinhauser 發現：原來都是腹部上的毛做的好事。

It scratches off tiny T-shirt fibers and directs them towards the belly button.

它會刮下細小的衣服纖維，然後將它們導向肚臍眼。

So that might be one mystery solved, but lint isn't the only thing inside these bizarre human crevices.

所以謎底揭曉了，但這些詭異的人體小洞裡可不止有棉絨。

Your belly button is a scar, your very first one.

你的肚臍是一道疤痕，你有生以來第一個。

It forms when a doctor snips your umbilical cord, and, depending on how it heals, you could have an outie or, more likely, an innie.

肚臍在醫生將你的臍帶剪開時形成，取決於傷口密合情況，你可能會有凸肚臍或凹肚臍。

And innies are ripe for colonization, not only by lint, hair, and dead skin cells, but also by bacteria.

凹肚臍可適合讓小東西聚集了，不只是棉絨、毛髮和皮膚細胞，還包含細菌。

In one study, 60 volunteers swabbed their belly buttons.

在一項研究中，60 位自願者用棉花棒從他們的肚臍取樣。

Researchers then analyzed the samples and found more than 2,300 kinds of bacteria.

研究人員接著分析這些樣本，發現了超過 2300 種細菌。

That's an average of 67 different kinds per belly button.

平均下來每一個肚臍裡就有 67 種不同細菌。

Now, many of those microbes aren't unique to belly buttons, like staphylococcus, which can lead to staph infections.

其中有許多種微生物並非只有肚臍才會有，像是葡萄狀球菌，可以導致葡萄球菌感染。

It shows up in noses, throats, hair, and, yes, even belly buttons.

它出沒在鼻腔、喉嚨、毛髮，以及肚臍。

But the researchers also discovered other bacteria never before seen on human skin, like marimonas, which scientists had previously only seen in the ocean.

但研究人員也發現了從未在人類皮膚上看過的細菌，例如 marimonas，從前只在海洋中發現過。

And they even found bacteria that chefs use to make cheese, and, yes, somebody did exactly that.

他們甚至發現了廚師用來製作起司的細菌，而且沒錯，還真的有人嘗試過。

She grew the belly-button bacteria in a petri dish and then added it to milk.

她用培養皿培養肚臍細菌然後加到牛奶裡。

Sure enough, after a few hours, the milk curdled into cheese.

理所當然幾小時後，牛奶凝結成起司。

Belly-button Brie, anyone?

肚臍乾酪，想來一口嗎？

Now, for the most part, the microbes in your navel are harmless.

不過大致上來說，你肚臍裡的微生物都是無害的。

In fact, recent studies suggest that bacteria on your body may strengthen your skin's defense system.

事實上，近期研究表示身體上的細菌或許還能加強你皮膚的防禦力。

But if you never clean your belly button, they'll grow unencumbered, and that can be a problem.

但如果你從來不清理你的肚臍，這些小東西會肆無忌憚地繁殖，這就是個問題了。

The best-case scenario is that your belly button will start to smell.

最好的情況是你的肚臍就只是會臭臭的。

When common navel microbes, like corynebacterium, build up, they emit pungent odors, similar to body odor.

一般的肚臍微生物 (例如棒狀直幹菌類) 堆積起來時，會散發出強烈的氣味，類似於體味。

But the worst case is that your navel will get infected, not just by staph but also by microbes that cause strep throat and yeast infections.

但最壞的情況是你的肚臍會感染，不止是葡萄球菌感染，有的微生物還會造成鏈球菌性咽炎和酵母菌感染。

That's right, you can get a yeast infection in your belly button, which can lead to itching and redness, and cause a clear or off-white discharge to leak out, which almost looks like cottage cheese.

沒錯，你的肚臍有可能得酵母菌感染，會導致發紅瘙癢，然後溢出一種清晰或米白色的分泌物，看起來簡直就像軟白乾酪。

So how does that cheese sound now?

這種「起司」聽起來如何？

While microbes colonize your belly button from the outside, there could also be an invader from the inside.

雖然微生菌是從外部攻佔了你的肚臍，也有可能有內部入侵者。

We're talking about belly-button hernias.

指的就是臍疝氣。

In the womb, the umbilical cord runs from your mom to you, passing through an opening in your abdominal muscles.

在子宮內，臍帶連結了你和你媽媽，穿過你腹部肌肉上的一個開口。

Normally that opening seals up after you're born, but, in some cases, it never really closes all the way.

那個開口通常會在你出生後密合，但在某些案例中並沒有完全密合。

This can allow internal organs to slip through, creating a bulge behind your belly button.

這有可能造成內臟滑出，在你的肚臍後方膨脹。

Navel hernias affect as many as one in five newborns in the US, but they're rarely life-threatening, and are far less common in adults.

在美國每五名新生兒就有一位有臍疝氣，但很少會帶來生命危險，在成人身上就更不常見了。

In fact, as long as you rinse your belly button with warm, soapy water once a week, the worst you'll have to put up with is a little fluff.

事實上，只要你每週一次用溫肥皂水刷刷你的肚臍，你會遇到最糟的情況也就只是一小團棉絨。