欢迎来到肚子王国

阳光从窗帘的缝隙里悄悄溜进来，在小明房间的地板上画出一道金色的光带。今天是星期六，不用上学，小明可以多睡一会儿懒觉。但是今天，他被一个奇怪的感觉唤醒了。

That morning, sunlight crept through the gap in the curtains, painting a golden strip on Xiaoming's bedroom floor. It was Saturday, no school today, so Xiaoming could sleep in a bit longer. But today, he was awakened by a strange sensation.

“咕噜——咕噜——”

"咕�噜——咕噜——"

小明的肚子发出了一连串奇怪的声音，就像有一条小鱼在他的肚子里吐泡泡一样。他翻了个身，用被子蒙住脑袋，想假装什么都没听见。可是那声音实在太响了，而且越来越频繁，越来越有节奏。

Xiaoming's tummy made a series of strange sounds, like a little fish blowing bubbles in his belly. He rolled over and pulled his blanket over his head, pretending he couldn't hear anything. But the sounds were just too loud, and they came more and more frequently, with an increasingly rhythmic pattern.

“咕噜噜——咕噜噜——”

"咕噜噜——咕噜噜——"

这下小明再也睡不着了。他坐起身来，揉了揉惺忪的睡眼，小手轻轻地按在肚子上。咦，肚子在动呢！不是抽筋，不是疼，就是轻轻地、软软地起伏着，好像里面住着什么活的东西。

Now Xiaoming couldn't sleep anymore. He sat up, rubbed his sleepy eyes, and gently pressed his little hand on his tummy. Oh my, his belly was moving! Not a cramp, not pain, just a gentle, soft rising and falling, as if something alive was living inside.

“小明，起床啦！”妈妈的声音从厨房传来，“牛奶已经热好了，快来喝吧！”

"Xiaoming, time to get up!" Mom's voice called from the kitchen. "The milk is warmed up, come drink it!"

小明跳下床，穿上拖鞋，噔噔噔地跑到厨房。妈妈正在煎鸡蛋，锅里发出滋滋的声响，香味弥漫在整个厨房里。桌上放着一杯冒着热气的牛奶，白白的，像一朵软绵绵的云。

Xiaoming jumped out of bed, slipped on his slippers, and ran咚咚咚 to the kitchen. Mom was frying eggs, the pan sizzling, and the aroma filled the whole kitchen. On the table sat a cup of steaming milk, white and fluffy, like a soft cloud.

“妈妈，为什么我的肚子会咕噜咕噜响啊？”小明端起牛奶，好奇地问。

"Mom, why does my tummy make those gurgling sounds?" Xiaoming picked up his milk and asked curiously.

妈妈转过身来，笑着说：“那是因为你的肚子里有一个神秘的小王国啊！”

Mom turned around and smiled. "That's because there's a mysterious little kingdom living in your tummy!"

“小王国？”小明睁大了眼睛，“我的肚子里有小人国吗？就像书里说的那种？”

"Little kingdom?" Xiaoming's eyes widened. "Are there little people living in my tummy? Like in the books, you know, like that?"

妈妈放下锅铲，在小明对面坐下来，用温柔的语气说：“比小人国还要神奇呢。你的肚子里住着成千上万的小居民，它们小得眼睛看不见，却时时刻刻陪伴着你。它们帮助你消化食物，让你长得高高的、壮壮的，还保护你不生病。”

Mom put down the spatula and sat down across from Xiaoming, saying in a gentle tone: "It's even more magical than a kingdom of little people. There are thousands upon thousands of tiny residents living in your tummy, too small to see with your eyes, yet they're with you every single moment. They help you digest food, make you grow tall and strong, and protect you from getting sick."

小明低头看了看自己的肚子，又抬起头看着妈妈，眼睛里闪烁着光芒：“真的吗？那它们长什么样子？它们住在什么样的房子里？”

Xiaoming looked down at his tummy, then looked up at Mom, his eyes sparkling. "Really? What do they look like? What kind of houses do they live in?"

妈妈摸了摸小明的头，说：“它们的家呀，是一条长长的、弯弯曲曲的隧道，叫做肠道。这条隧道从你的嘴巴开始，一直延伸到你的屁股，就像一条超级长的滑梯，只是这条滑梯是建在你身体里面的。”

Mom patted Xiaoming's head and said, "Their home is a long, winding tunnel called the intestines. This tunnel starts from your mouth and goes all the way to your bottom, just like a super long slide, except this slide is built inside your body."

“一条隧道？”小明想象着，“它是什么样的隧道？”

"A tunnel?" Xiaoming imagined. "What kind of tunnel is it?"

“想象一下，”妈妈说，“如果你把自己缩小一百万倍——不，一万亿倍——变得比一粒沙子还要小几百万倍，那么你就能够走进那条隧道了。”

"Imagine this," Mom said, "if you shrink yourself a million times—no, a trillion times—so small that you're millions of times smaller than a grain of sand, then you could walk into that tunnel."

小明喝了一大口牛奶，脑子里开始飞快地想象起来。他想象自己变得越来越小、越来越小，小到像一颗微小的尘埃。

Xiaoming took a big gulp of milk, and his mind started racing with imagination. He imagined himself getting smaller and smaller, so tiny like a speck of dust.

“那条隧道啊，”妈妈继续说，“墙壁是粉红色的，软软的、湿湿的，就像草莓果冻一样。隧道的顶上挂着一盏盏小小的灯，发出柔和的光芒，把整个隧道照得温暖又明亮。”

"That tunnel," Mom continued, "has pink walls that are soft and moist, just like strawberry jelly. Hanging from the top of the tunnel are little lamps that give off a soft glow, making the whole tunnel warm and bright."

“哇——”小明惊叹道，“那一定很漂亮！”

"Wow—" Xiaoming exclaimed. "That must be beautiful!"

“可不是嘛！”妈妈笑了，“而且隧道里非常热闹。有的小居民在墙壁上爬来爬去，有的小居民在隧道里滚来滚去，还有一些更小的居民住在墙壁的褶皱里，就像住在一座座小山洞里一样。”

"Exactly!" Mom laughed. "And it's very lively inside the tunnel. Some residents crawl along the walls, some roll around inside the tunnel, and even tinier ones live in the folds of the walls, like in little caves in mountains."

小明听得入了迷，牛奶都快忘记喝了。他问：“妈妈，那这些小居民叫什么名字呢？”

Xiaoming was fascinated, almost forgetting to drink his milk. He asked, "Mom, what are these little residents called?"

妈妈眨眨眼睛，说：“它们有很多名字。你可以叫它们'肠道居民'，也可以叫它们'肠道微生物'。微生物的意思就是很小很小的生物，小到要用超级特别的显微镜才能看到。”

Mom winked and said, "They have many names. You can call them 'intestinal residents,' or 'gut microbes.' Microbe means a very, very tiny organism, so small that you need a super special microscope to see them."

“微生物……”小明重复着这个新学的词，“它们有多小呢？”

"Microbes..." Xiaoming repeated this new word. "How small are they?"

“嗯，”妈妈想了想该怎么解释，“如果把一根头发丝横着放在地上，那么一个微生物站在上面，就像一个人站在一栋大楼顶上一样，看起来还是小小的。但是如果把一万个微生物排成一排——”

"Well," Mom thought about how to explain this, "if you lay a strand of hair horizontally on the ground, then a microbe standing on it would be like a person standing on top of a building—and they'd still look tiny. But if you lined up ten thousand microbes in a row—"

小明抢着说：“也才一根头发丝那么长！”

Xiaoming interjected, "That would only be as long as one strand of hair!"

“对极了！”妈妈赞许地点点头，“你真聪明，小明。所以一克你的便便里面，大约就有十亿个这样的微生物。一克才多重呢？大约是一片小树叶的重量。”

"Exactly right!" Mom nodded approvingly. "You're so smart, Xiaoming. So in just one gram of your poop, there are about a billion such microbes. How much is one gram? About the weight of a small leaf."

小明惊讶得差点把牛奶喷出来：“十亿个？那得数到什么时候啊？”

Xiaoming was so surprised he nearly sprayed his milk. "A billion? How long would it take to count to that?"

“对人类来说，那是数都数不清的数字。”妈妈说，“就算你每秒数一个，日夜不停地数，也要数上三十多年呢！”

"For humans, that's an uncountable number," Mom said. "Even if you counted one per second, non-stop day and night, it would take over thirty years!"

小明的眼睛瞪得更大了：“那我肚子里有多少微生物啊？”

Xiaoming's eyes grew even wider. "So how many microbes are in my tummy?"

妈妈说：“我们每个人的肠道里，大约住着一百万亿个微生物。这个数字太大了，我给你打个比方吧。”

Mom said, "In each of our intestines, there are about a hundred trillion microbes. That number is too big, let me give you an example."

“什么样的比方？”

"What kind of example?"

“如果你把肠道里所有的微生物都拿出来称一称，它们的重量大约是1到2公斤。想想看，差不多就是你刚出生时那么重！”

"If you took all the microbes out of your intestine and weighed them, they'd weigh about 1 to 2 kilograms. Think about it—that's almost as heavy as when you were just born!"

小明低头看着自己的肚子，又看看桌上那杯牛奶，喃喃自语道：“原来我的肚子里住着这么多小伙伴啊。它们每天都在那里，一定很热闹吧？”

Xiaoming looked down at his tummy, then at the cup of milk on the table, murmuring, "So there are so many little friends living in my tummy. It must be very lively there every day, right?"

“非常热闹！”妈妈说，“想象一下，如果你的身体是一个大大的国家，那么肠道就是这座国家的首都，而微生物就是首都里的市民。它们种类繁多，有各种各样的'居民'，有的像小圆球，有的像小棒子，有的像弯弯的月亮，还有的像一条细细的丝线。”

"Very lively!" Mom said. "Imagine if your body was a big country, then your intestine would be the capital city of that country, and the microbes would be the citizens. There are many different kinds, all sorts of 'residents'—some look like little balls, some like little sticks, some like curved moons, and some like thin threads."

小明喝完最后一口牛奶，把杯子放下，眼睛里全是好奇：“妈妈，这些小居民是怎么住进我的肚子里的呢？”

Xiaoming finished his last sip of milk, set down the cup, his eyes full of curiosity. "Mom, how did these little residents move into my tummy?"

妈妈开始收拾碗筷，一边收拾一边说：“这个问题问得真好！当你还在妈妈肚子里的时候，你的肠道几乎是干干净净的，没有微生物。”

Mom started tidying up the dishes while she spoke. "That's a great question! When you were still in Mom's tummy, your intestines were almost completely clean, with no microbes."

“那我肚子里的微生物是从哪里来的呢？”

"So where did the microbes in my tummy come from?"

妈妈在洗碗池边转过身来，认真地看着小明说：“从你出生的那一刻起，微生物就开始住进来了。当你经过妈妈的产道时，你会吞下一些妈妈身体里的微生物，它们就成为了你肠道里的第一批居民。”

Mom turned around at the sink and looked at Xiaoming seriously. "From the moment you were born, microbes started moving in. When you passed through Mom's birth canal, you swallowed some microbes from Mom's body, and the