TED2014
Rob Knight: How our microbes make us who we are
ロブ・ナイト: 微生物がどのようにして私達を作っているのか
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ロブ・ナイトは、人体内の微生物研究におけるパイオニアです。私達の体内に宿る小さな単細胞生物群は、私達の健康において、極めて大きな役割を担っています。そして、この分野は未だに良く知られていません。「私達が体内に抱えている３ポンドの微生物は、ゲノム内のどの遺伝子よりも重要かもしれません」と言う、その彼の理由を聴いてみましょう。
Rob Knight - Microbial ecologist
Rob Knight explores the unseen microbial world that exists literally right under our noses -- and everywhere else on (and in) our bodies. Full bio
Rob Knight explores the unseen microbial world that exists literally right under our noses -- and everywhere else on (and in) our bodies. Full bio
Double-click the English transcript below to play the video.
00:13
We humans have always been very concerned
about the health of our bodies,
about the health of our bodies,
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誰でも常に健康に関心がありますが
00:17
but we haven't always been that good
at figuring out what's important.
at figuring out what's important.
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今まで必ずしも何が大切なのか
理解していたとは限りません
理解していたとは限りません
00:21
Take the ancient Egyptians, for example:
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例えば古代エジプトを見ると
00:23
very concerned about the body parts
they thought they'd need in the afterlife,
they thought they'd need in the afterlife,
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死後の世界に必要だと思われた
体の部分はとても大事に扱われ
体の部分はとても大事に扱われ
00:27
but they left some parts out.
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その一方ある部分は除外されました
00:29
This part, for example.
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つまり
00:32
Although they very carefully
preserved the stomach, the lungs,
preserved the stomach, the lungs,
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胃 肺 肝臓などは
00:35
the liver, and so forth,
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注意深く保存されましたが
00:36
they just mushed up the brain,
drained it out through the nose,
drained it out through the nose,
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脳は潰され鼻から抽出され
00:39
and threw it away,
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捨てられていました
00:41
which makes sense, really,
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確かに
00:42
because what does a brain
do for us anyway?
do for us anyway?
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脳は一体何の役に立つと言うのでしょう
00:45
But imagine if there were a kind
of neglected organ in our bodies
of neglected organ in our bodies
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しかし脳程の重さで
我々自身ともいえる
我々自身ともいえる
00:48
that weighed just as much as the brain
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重要な臓器が我々の体に
00:50
and in some ways was just
as important to who we are,
as important to who we are,
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他にあるでしょうか
00:53
but we knew so little about
and treated with such disregard.
and treated with such disregard.
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なのに 知られている事も関心も
殆どありませんでした
殆どありませんでした
00:57
And imagine if,
through new scientific advances,
through new scientific advances,
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しかし新しい科学の進歩で
01:00
we were just beginning to understand
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ヒトの理解に役立つ
01:01
its importance to how
we think of ourselves.
we think of ourselves.
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重要な事柄が
分かり始めて来たばかりだとしたら
分かり始めて来たばかりだとしたら
01:04
Wouldn't you want to know more about it?
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もっと それについて
知りたいと思いませんか
知りたいと思いませんか
01:07
Well, it turns out that we do
have something just like that:
have something just like that:
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実はその脳に似た物が
他にもあるのです
他にもあるのです
01:10
our gut,
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我々の腸です
01:12
or rather, its microbes.
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腸内の微生物と
言った方がいいでしょう
言った方がいいでしょう
01:15
But it's not just the microbes
in our gut that are important.
in our gut that are important.
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でも大切なのは
腸内微生物だけではありません
腸内微生物だけではありません
01:18
Microbes all over our body
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体内外の微生物が
01:19
turn out to be really critical
to a whole range of differences
to a whole range of differences
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広範囲に渡り影響を及ぼし
大きく健康を左右していることが
大きく健康を左右していることが
01:22
that make different people who we are.
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分かってきました
01:25
So for example, have you ever noticed
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その例として
01:27
how some people get bitten by mosquitos
way more often than others?
way more often than others?
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蚊に刺され易い人がいる事に
気付かれた事がありますか
気付かれた事がありますか
01:31
It turns out that everyone's anecdotal
experience out camping is actually true.
experience out camping is actually true.
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誰でも同じような経験がキャンプでありますね
01:36
For example, I seldom
get bitten by mosquitos,
get bitten by mosquitos,
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私自身あまり蚊に刺される事はありませんが
01:38
but my partner Amanda
attracts them in droves,
attracts them in droves,
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私の妻アマンダには蚊の大群が寄ってきます
01:41
and the reason why is that we have
different microbes on our skin
different microbes on our skin
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その理由は人それぞれ
皮膚には異なる微生物が
皮膚には異なる微生物が
01:44
that produce different chemicals
that the mosquitos detect.
that the mosquitos detect.
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固有の化学物質を
分泌しているからです
分泌しているからです
01:48
Now, microbes are also really important
in the field of medicine.
in the field of medicine.
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微生物は医療の分野でも とても重要です
01:51
So, for example, what microbes
you have in your gut
you have in your gut
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一例として腸内微生物は
01:54
determine whether particular painkillers
are toxic to your liver.
are toxic to your liver.
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肝臓に対し毒性を持つ鎮痛剤や
01:58
They also determine whether or not other
drugs will work for your heart condition.
drugs will work for your heart condition.
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心臓病に効く薬を判断します
02:02
And, if you're a fruit fly, at least,
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そして あなたがミバエなら
02:05
your microbes determine
who you want to have sex with.
who you want to have sex with.
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あなたのパートナーは
あなたの微生物に決められます
あなたの微生物に決められます
02:08
We haven't demonstrated this in humans yet
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これはヒトでは検証されていませんが
02:10
but maybe it's just a matter of time
before we find out. (Laughter)
before we find out. (Laughter)
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それが分かるのは時間の問題でしょう
（笑）
（笑）
02:15
So microbes are performing
a huge range of functions.
a huge range of functions.
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このように微生物は
広範囲に渡り活動しています
広範囲に渡り活動しています
02:17
They help us digest our food.
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食物を消化したり
02:19
They help educate our immune system.
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免疫系に働きかけ
02:21
They help us resist disease,
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病気に対抗したりし
02:23
and they may even
be affecting our behavior.
be affecting our behavior.
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また我々の行動にさえも影響を及ぼします
02:26
So what would a map of all these
microbial communities look like?
microbial communities look like?
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では微生物叢(そう)の分布図とは
どんなものでしょうか
どんなものでしょうか
02:30
Well, it wouldn't look exactly like this,
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全くこれと同じではないでしょうが
02:32
but it's a helpful guide
for understanding biodiversity.
for understanding biodiversity.
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生物学的多様性を理解するには
助けとなる手段となります
助けとなる手段となります
02:35
Different parts of the world
have different landscapes of organisms
have different landscapes of organisms
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固有の様態をした有機体が
02:39
that are immediately characteristic
of one place or another
of one place or another
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世界中その土地土地にいて
それが直接その地の
それが直接その地の
02:43
or another.
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特性となります
02:45
With microbiology, it's kind of the same,
although I've got to be honest with you:
although I've got to be honest with you:
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微生物学でも同じ様な事が言えますが
02:49
All the microbes essentially
look the same under a microscope.
look the same under a microscope.
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正直言って 顕微鏡の下では
微生物は本質的に皆似ているので
微生物は本質的に皆似ているので
02:52
So instead of trying
to identify them visually,
to identify them visually,
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様相から識別するのでなく
02:55
what we do is we look
at their DNA sequences,
at their DNA sequences,
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ヒト微生物のDNA配列を
02:57
and in a project called
the Human Microbiome Project,
the Human Microbiome Project,
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ヒト微生物叢プロジェクト
と呼ばれるプロジェクトで
と呼ばれるプロジェクトで
03:00
NIH funded this $173 million project
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NIHから１億7300万ドルの
支援を受け研究しています
支援を受け研究しています
03:04
where hundreds
of researchers came together
of researchers came together
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何百人もの研究者が集まり
03:06
to map out all the A's, T's, G's, and C's,
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ヒト微生物全ての
03:09
and all of these microbes
in the human body.
in the human body.
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ATGC配列を読み取り
03:11
So when we take them together,
they look like this.
they look like this.
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集めて見てみるとこんな感じです
03:14
It's a bit more difficult
to tell who lives where now, isn't it?
to tell who lives where now, isn't it?
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どれがどれだか
ちょっと見分けがつきませんね
ちょっと見分けがつきませんね
03:18
What my lab does is develop
computational techniques that allow us
computational techniques that allow us
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我々が開発した計算技法で
03:22
to take all these terabytes
of sequence data
of sequence data
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テラバイトの配列データ全てを
03:24
and turn them into something
that's a bit more useful as a map,
that's a bit more useful as a map,
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マップとしてもっとよく使える様にし
03:27
and so when we do that
with the human microbiome data
with the human microbiome data
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250人の健康なボランティアから採った
03:30
from 250 healthy volunteers,
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ヒト微生物叢のデータを用い作ったものが
03:32
it looks like this.
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この様になります
03:35
Each point here represents
all the complex microbes
all the complex microbes
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図の一点ずつが複雑な微生物の集合体
03:38
in an entire microbial community.
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微生物叢を表します
03:40
See, I told you they basically
all look the same.
all look the same.
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言った通り どれも似ているでしょう
03:43
So what we're looking at is each point
represents one microbial community
represents one microbial community
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１つの点が 健康な人体の１カ所から採取された
03:46
from one body site
of one healthy volunteer.
of one healthy volunteer.
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微生物叢を表しています
03:49
And so you can see that there's different
parts of the map in different colors,
parts of the map in different colors,
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様々な色がその箇所毎に個々の大陸を作って
03:53
almost like separate continents.
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地図を作っているかの様です
03:54
And what it turns out to be
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これで分かることは
03:56
is that those, as the different
regions of the body,
regions of the body,
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体の箇所により非常に
03:58
have very different microbes in them.
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微生物叢が異なるという事です
04:00
So what we have is we have
the oral community up there in green.
the oral community up there in green.
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緑色は口腔の
04:04
Over on the other side,
we have the skin community in blue,
we have the skin community in blue,
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その反対側の青色は皮膚の
04:07
the vaginal community in purple,
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紫色は膣内の
04:09
and then right down at the bottom,
we have the fecal community in brown.
we have the fecal community in brown.
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そして下の茶色の塊は
糞便の微生物叢を表しています
糞便の微生物叢を表しています
04:13
And we've just over the last few years
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そしてこの数年
04:15
found out that the microbes
in different parts of the body
in different parts of the body
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体の部分により
微生物叢には信じられない程の
微生物叢には信じられない程の
04:18
are amazingly different from one another.
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多様性がある事が分かりました
04:20
So if I look at just one person's microbes
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たった１人の口や腸内の
04:23
in the mouth and in the gut,
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微生物を見ただけでも
04:25
it turns out that the difference between
those two microbial communities
those two microbial communities
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その２組の微生物叢の違いは
04:28
is enormous.
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とてつもなく
04:30
It's bigger than the difference
between the microbes in this reef
between the microbes in this reef
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この珊瑚礁と草原の微生物叢の違いより
04:33
and the microbes in this prairie.
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著しいのです
04:36
So this is incredible
when you think about it.
when you think about it.
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そう考えると すごい事なんです
04:38
What it means is that a few feet
of difference in the human body
of difference in the human body
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60センチ離れただけで人体の
微生物生態系は大きく変わり
微生物生態系は大きく変わり
04:42
makes more of a difference
to your microbial ecology
to your microbial ecology
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その相違は地球上何千キロ行っても
04:44
than hundreds of miles on Earth.
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あり得ない程の膨大さなのです
04:46
And this is not to say that two people
look basically the same
look basically the same
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そして 同じヒトだからといって
我々の微生物の生態系は
我々の微生物の生態系は
04:49
in the same body habitat, either.
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皆同じだという訳ではありません
04:51
So you probably heard
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多分ご存知だと思いますが
04:53
that we're pretty much all the same
in terms of our human DNA.
in terms of our human DNA.
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遺伝子学的に言って
私たちは皆似ています
私たちは皆似ています
04:56
You're 99.99 percent identical
in terms of your human DNA
in terms of your human DNA
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ヒトDNAから見ると私たちは99.9%
05:00
to the person sitting next to you.
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隣にいる人と同じですが
05:02
But that's not true of your gut microbes:
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微生物学的にはそうではなく
05:04
you might only share 10 percent similarity
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隣に座っている人とあなたは
05:07
with the person sitting next to you
in terms of your gut microbes.
in terms of your gut microbes.
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同じ微生物を10%共有するかしないかです
05:10
So that's as different
as the bacteria on this prairie
as the bacteria on this prairie
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それが この草原や森のバクテリアと
05:13
and the bacteria in this forest.
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ヒトのそれとの違いです
05:16
So these different microbes
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この違いが
05:17
have all these different kinds
of functions that I told you about,
of functions that I told you about,
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今話した様な種々の機能—
05:21
everything from digesting food
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食物の消化から
05:22
to involvement
in different kinds of diseases,
in different kinds of diseases,
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あらゆる病気や薬物の代謝—
05:25
metabolizing drugs, and so forth.
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などに関与してきます
05:27
So how do they do all this stuff?
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どうして 微生物にこんな事が
できるのでしょう？
できるのでしょう？
05:29
Well, in part it's because
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その理由の一部は
05:31
although there's just three pounds
of those microbes in our gut,
of those microbes in our gut,
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私たちのお腹にいる
1.4キロ程の微生物の数が
1.4キロ程の微生物の数が
05:34
they really outnumber us.
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人の数を凌いでいるからです
05:36
And so how much do they outnumber us?
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どれ程人を凌いでいるかと言うと
05:38
Well, it depends on what
you think of as our bodies.
you think of as our bodies.
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比較するには地球上の人口では間に合いません
05:41
Is it our cells?
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細胞と比べてはどうでしょう
05:43
Well, each of us consists
of about 10 trillion human cells,
of about 10 trillion human cells,
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人体は約10兆程のヒト細胞で成っていますが
05:46
but we harbor as many
as 100 trillion microbial cells.
as 100 trillion microbial cells.
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宿している微生物細胞の数は100兆で
05:49
So they outnumber us 10 to one.
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ヒト細胞数の10倍です
05:52
Now, you might think, well,
we're human because of our DNA,
we're human because of our DNA,
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「でもヒトはDNAで決まるのだから」
と思われるでしょうが
と思われるでしょうが
05:56
but it turns out that each of us has
about 20,000 human genes,
about 20,000 human genes,
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１人に約２万の遺伝子がある事が
分かっています—
分かっています—
05:59
depending on what you count exactly,
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正確に何を数えるかにも依りますが—
06:01
but as many as two million
to 20 million microbial genes.
to 20 million microbial genes.
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しかし微生物遺伝子は２百万から２千万です
06:06
So whichever way we look at it,
we're vastly outnumbered
we're vastly outnumbered
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どちらを向いても共生微生物達の数には
06:08
by our microbial symbionts.
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とうてい敵いっこありません
06:11
And it turns out that in addition
to traces of our human DNA,
to traces of our human DNA,
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そして私たちが触るもの全てに
ヒトDNAだけでなく
ヒトDNAだけでなく
06:15
we also leave traces
of our microbial DNA
of our microbial DNA
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微生物のDNAまでをも我々は
06:17
on everything we touch.
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後に残すことが分かっています
06:19
We showed in a study a few years ago
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数年前の我々の研究で
06:20
that you can actually match
the palm of someone's hand up
the palm of someone's hand up
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コンピュータのマウスと
それを使う人の手のひらの
それを使う人の手のひらの
06:23
to the computer mouse
that they use routinely
that they use routinely
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微生物が95%までの正確さで
06:25
with up to 95 percent accuracy.
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マッチしました
06:28
So this came out in a scientific journal
a few years ago,
a few years ago,
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これは数年前 科学誌に発表されましたが
それより重要な『CSI: マイアミ』に
採用されたので
採用されたので
06:31
but more importantly,
it was featured on "CSI: Miami,"
it was featured on "CSI: Miami,"
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06:33
so you really know it's true.
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これで信じてもらえるでしょう
06:35
(Laughter)
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（笑）
06:36
So where do our microbes
come from in the first place?
come from in the first place?
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そもそも我々の微生物は
どこから来るのでしょう
どこから来るのでしょう
06:40
Well if, as I do, you have dogs or kids,
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犬も子供もいる方は—
私には両方いますが—
私には両方いますが—
06:43
you probably have
some dark suspicions about that,
some dark suspicions about that,
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多分 「もしかしたら」
と思っていらっしゃるでしょう
と思っていらっしゃるでしょう
06:45
all of which are true, by the way.
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実は全くその通りでなのです
06:47
So just like we can match
you to your computer equipment
you to your computer equipment
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コンピュータとそれを使う人の微生物が
06:50
by the microbes you share,
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マッチするだけでなく
06:51
we can also match you up to your dog.
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犬と飼い主の微生物もマッチします
06:54
But it turns out that in adults,
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しかし成人の微生物は比較的
06:56
microbial communities
are relatively stable,
are relatively stable,
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変動しない事が分かっているので
06:58
so even if you live together with someone,
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誰かと共同生活をしても
07:00
you'll maintain your separate
microbial identity
microbial identity
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成人は固有の微生物を
07:02
over a period of weeks,
months, even years.
months, even years.
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何週間も時には何年も持ち続けます
07:05
It turns out that our
first microbial communities
first microbial communities
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初期のヒトの微生物叢は
出産で大きく差が出る
出産で大きく差が出る
07:08
depend a lot on how we're born.
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という事も分かっています
07:11
So babies that come out
the regular way,
the regular way,
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普通分娩で産まれた赤ちゃんは
07:13
all of their microbes are basically
like the vaginal community,
like the vaginal community,
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基本的に母親の膣内微生物叢を持ち
07:16
whereas babies that are
delivered by C-section,
delivered by C-section,
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一方 帝王切開で産まれた赤ちゃんの
07:18
all of their microbes instead
look like skin.
look like skin.
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微生物は全て皮膚常在菌となります
07:21
And this might be associated
with some of the differences
with some of the differences
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帝王切開で産まれた人は
07:24
in health associated with Cesarean birth,
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微生物との関わりがある
07:27
such as more asthma, more allergies,
even more obesity,
even more obesity,
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嘆息 アレルギーそして肥満さえも
普通分娩の人より罹り易く
普通分娩の人より罹り易く
07:30
all of which have been linked
to microbes now,
to microbes now,
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出産と健康との関係が
考えられています
考えられています
07:33
and when you think about it,
until recently, every surviving mammal
until recently, every surviving mammal
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思えば ごく最近まで ほ乳類は
07:37
had been delivered by the birth canal,
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全て自然分娩でした
07:39
and so the lack
of those protective microbes
of those protective microbes
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我々と共進化して来た
07:41
that we've co-evolved with
might be really important
might be really important
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保護的微生物がないという事は
07:44
for a lot of these different conditions
that we now know involve the microbiome.
that we now know involve the microbiome.
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微生物が関わる健康問題には
本当に重大な事かもしれません
本当に重大な事かもしれません
07:48
When my own daughter was born
a couple of years ago
a couple of years ago
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数年前 私の娘が産まれた時
07:51
by emergency C-section,
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緊急の帝王切開でしたが
07:53
we took matters into our own hands
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私と妻は自分たちで
07:55
and made sure she was coated
with those vaginal microbes
with those vaginal microbes
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普通分娩の様に娘が母体の膣内常在菌に
07:58
that she would have gotten naturally.
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覆われる様にしました
08:00
Now, it's really difficult to tell
whether this has had an effect
whether this has had an effect
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さあ これが娘の健康に
どんな効果があったのか
どんな効果があったのか
08:03
on her health specifically, right?
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全く分かりませんが
08:05
With a sample size of just one child,
no matter how much we love her,
no matter how much we love her,
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どれ程の愛情を持ってしても
たった１人の子供からだけのサンプルサイズでは
たった１人の子供からだけのサンプルサイズでは
08:09
you don't really have
enough of a sample size
enough of a sample size
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一般的データを得るには
08:11
to figure out what happens on average,
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十分ではありません
08:13
but at two years old,
she hasn't had an ear infection yet,
she hasn't had an ear infection yet,
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この２年間 娘は耳感染症に
罹った事はありません
罹った事はありません
08:16
so we're keeping our fingers
crossed on that one.
crossed on that one.
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これからも何もない事を祈っています
08:18
And what's more, we're starting
to do clinical trials with more children
to do clinical trials with more children
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さらに子供たちを使って
微生物に保護的な効果が
微生物に保護的な効果が
08:22
to figure out whether
this has a protective effect generally.
this has a protective effect generally.
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一様にあるものかどうか
臨床研究を始めました
臨床研究を始めました
08:27
So how we're born has a tremendous effect
on what microbes we have initially,
on what microbes we have initially,
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出産方法が大きく影響し
最初の微生物生態系が決まります
最初の微生物生態系が決まります
08:32
but where do we go after that?
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では この後どうなるのでしょう？
08:34
What I'm showing you
again here is this map
again here is this map
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ヒト微生物プロジェクトのデータ分布図を
08:36
of the Human Microbiome Project Data,
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もう一度ご覧ください
08:38
so each point represents
a sample from one body site
a sample from one body site
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点が一人の体の一部から採った微生物叢を表し
08:41
from one of 250 healthy adults.
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全部で250人からの物です
08:43
And you've seen children
develop physically.
develop physically.
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子供の身体的成長や
08:45
You've seen them develop mentally.
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精神的成長は目にできたとしても
08:47
Now, for the first time,
you're going to see
you're going to see
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これは初めてご覧になる物でしょう
ある同僚の子供の微生物学的成長です
08:50
one of my colleague's children
develop microbially.
develop microbially.
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3358
08:53
So what we are going to look at
191
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今からご覧になるのは
ある赤ちゃんの便からの物で
08:54
is we're going to look
at this one baby's stool,
at this one baby's stool,
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2687
08:57
the fecal community,
which represents the gut,
which represents the gut,
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腸内細菌叢を代表するものです
09:00
sampled every week
for almost two and a half years.
for almost two and a half years.
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２年半近く 毎週試料を採取しました
09:03
And so we're starting on day one.
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１日目から始めました
09:04
What's going to happen is that the infant
is going to start off as this yellow dot,
is going to start off as this yellow dot,
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嬰児はまず最初に黄色い粒
09:08
and you can see that he's starting off
basically in the vaginal community,
basically in the vaginal community,
197
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3480
膣内微生物叢から始まります
09:12
as we would expect from his delivery mode.
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2026
自然分娩から当然期待される事ですね
09:14
And what's going to happen
over these two and a half years
over these two and a half years
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２年半の間で
09:17
is that he's going to travel
all the way down
all the way down
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この子の微生物叢は
09:19
to resemble the adult fecal community from
healthy volunteers down at the bottom.
healthy volunteers down at the bottom.
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健康な成人の糞便微生物叢に似通ってきます
09:23
So I'm just going to start this going
and we'll see how that happens.
and we'll see how that happens.
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始めますので どうなるか見て下さい
09:26
What you can see, and remember
each step in this is just one week,
each step in this is just one week,
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見ているのは１週間に１ステップです
09:30
what you can see is that week to week,
204
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週毎に
子供の糞便微生物叢の変化が見られ
09:32
the change in the microbial community
of the feces of this one child,
of the feces of this one child,
205
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4683
09:37
the differences week to week
are much greater
are much greater
206
565498
2551
その週毎の変化は
ヒト微生物プロジェクトが行った
ヒト微生物プロジェクトが行った
09:40
than the differences between
individual healthy adults
individual healthy adults
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2531
コホートの健康な成人と比べると
09:42
in the Human Microbiome Project cohort,
208
570580
1950
ずっと大きいのです
09:44
which are those brown dots
down at the bottom.
down at the bottom.
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2476
その成人の微生物叢は
下の茶色の物です
下の茶色の物です
09:47
And you can see he's starting
to approach the adult fecal community.
to approach the adult fecal community.
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3197
ご覧の様に成人の便のそれに
近くなっているのが見れますね
近くなっているのが見れますね
09:50
This is up to about two years.
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1515
これが約２年程続き
09:51
But something amazing
is about to happen here.
is about to happen here.
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2170
ここでとても驚くことが起きます
09:53
So he's getting antibiotics
for an ear infection.
for an ear infection.
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3088
この子は耳感染症に対する抗体ができるのです
09:56
What you can see is
this huge change in the community,
this huge change in the community,
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ここで微生物叢に大きな変化が現れてきて
09:59
followed by a relatively rapid recovery.
215
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2058
耳感染症からの回復が比較的速くなります
10:01
I'll just rewind that for you.
216
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2182
巻き戻してみましょう
10:05
And what we can see is that
just over these few weeks,
just over these few weeks,
217
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3589
ほんのこの数週間で
10:08
we have a much more radical change,
218
596929
1933
劇的な変化が見られます
10:10
a setback of many months
of normal development,
of normal development,
219
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2530
何ヶ月も進展があまりなく
10:13
followed by a relatively rapid recovery,
220
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2252
838日ぐらいして—
10:15
and by the time he reaches day 838,
221
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このビデオの最後の方ですが—
10:19
which is the end of this video,
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1719
比較的回復が早くなるのです
10:21
you can see that he has essentially
reached the healthy adult stool community,
reached the healthy adult stool community,
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3697
この頃には根本的に
成人の便と同じ微生物叢になります
成人の便と同じ微生物叢になります
10:25
despite that antibiotic intervention.
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2448
途中 抗生物質の介入
有無に関わらずです
有無に関わらずです
10:27
So this is really interesting
because it raises fundamental questions
because it raises fundamental questions
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615641
3328
実に興味深い事です
なぜなら この事から
なぜなら この事から
10:30
about what happens when we intervene
at different ages in a child's life.
at different ages in a child's life.
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4099
年齢が変わると どうだろうか
という基本的疑問が湧いてくるからです
という基本的疑問が湧いてくるからです
10:35
So does what we do early on, where
the microbiome is changing so rapidly,
the microbiome is changing so rapidly,
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3611
微生物叢の変化が大きい
生後数年間には我々の行動が
生後数年間には我々の行動が
10:38
actually matter,
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1300
影響するのでしょうか
10:39
or is it like throwing a stone
into a stormy sea,
into a stormy sea,
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2483
それともその影響は
あまりに微々たるもので
あまりに微々たるもので
10:42
where the ripples will just be lost?
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何も影響しないのでしょうか
10:45
Well, fascinatingly, it turns out
that if you give children antibiotics
that if you give children antibiotics
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興味深い事に 生後６ヶ月間 嬰児に
10:49
in the first six months of life,
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抗生物質を投与すると
10:50
they're more likely
to become obese later on
to become obese later on
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2785
抗生物質を与えなかった子供と比べ
10:53
than if they don't get antibiotics then
or only get them later,
or only get them later,
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641770
3127
後に肥満になる率が高い
というデータがあり
というデータがあり
10:56
and so what we do early on
may have profound impacts
may have profound impacts
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2946
生後６ヶ月間は十分注意しないと
10:59
on the gut microbial community
and on later health
and on later health
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3497
初期の腸内細菌叢は後々
大きくその人の健康に影響する
大きくその人の健康に影響する
11:03
that we're only beginning to understand.
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2326
という事が分かってきました
11:05
So this is fascinating, because one day,
in addition to the effects
in addition to the effects
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4156
これで抗生物に対し耐性が出来る
11:09
that antibiotics have
on antibiotic-resistant bacteria,
on antibiotic-resistant bacteria,
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2646
薬物耐性菌の問題はもちろんの事—
11:12
which are very important,
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1696
これは大切な事ですが—
11:14
they may also be degrading
our gut microbial ecosystems,
our gut microbial ecosystems,
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2903
腸内細菌叢の変化で その保護力が弱まり
11:17
and so one day we may come
to regard antibiotics with the same horror
to regard antibiotics with the same horror
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エジプト人がミイラ作りの際
脳を潰し抽出するのに使った
脳を潰し抽出するのに使った
11:20
that we currently reserve
for those metal tools
for those metal tools
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2463
金属製の道具に対するような恐怖で
11:22
that the Egyptians used to use
to mush up the brains
to mush up the brains
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2459
我々は抗生物質を扱う事になるかもしれない
11:25
before they drained them out
for embalming.
for embalming.
245
673261
2064
ということを興味深く考えさせられます
11:27
So I mentioned that microbes
have all these important functions,
have all these important functions,
246
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3021
これが先ほどの微生物の重要な機能です
11:30
and they've also now,
just over the past few years,
just over the past few years,
247
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2649
また過去ほんの数年で
11:32
been connected to a whole range
of different diseases,
of different diseases,
248
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2833
微生物があらゆる病気
11:35
including inflammatory bowel disease,
249
683828
2085
炎症性腸疾患、心臓病、結腸がん
11:37
heart disease, colon cancer,
250
685913
1724
又は肥満にも関連している
11:39
and even obesity.
251
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1830
という事が分かって来たのです
11:41
Obesity has a really
large effect, as it turns out,
large effect, as it turns out,
252
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2646
肥満には大きく影響し
11:44
and today, we can tell
whether you're lean or obese
whether you're lean or obese
253
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2393
今では腸内微生物を見て
11:46
with 90 percent accuracy
254
694506
1879
90%の正確さで
11:48
by looking at the microbes in your gut.
255
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2112
肥満かどうかわかるのです
11:50
Now, although that might sound impressive,
256
698497
2289
これに感心なさるかもしれませんが
11:52
in some ways it's a little bit problematic
as a medical test,
as a medical test,
257
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3331
ある意味では医療検査としては
ちょっと問題になります
ちょっと問題になります
11:56
because you can probably tell
which of these people is obese
which of these people is obese
258
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2997
恐らく微生物の事など知らなくても
11:59
without knowing anything
about their gut microbes,
about their gut microbes,
259
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2752
見ただけでこの２人のどちらが
肥満がどうか見分けられます
肥満がどうか見分けられます
12:01
but it turns out that even
if we sequence their complete genomes
if we sequence their complete genomes
260
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3043
全ゲノムの配列を解読し
12:04
and had all their human DNA,
261
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1657
ヒトDNAから判断すると
12:06
we could only predict which one
was obese with about 60 percent accuracy.
was obese with about 60 percent accuracy.
262
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4366
肥満だと決定できるのは
60%の正確さだからです
60%の正確さだからです
12:10
So that's amazing, right?
263
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1374
驚きますね
12:12
What it means that the three pounds
of microbes that you carry around with you
of microbes that you carry around with you
264
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3812
ということは我々が抱えている
約1.5キロの微生物は
約1.5キロの微生物は
12:16
may be more important
for some health conditions
for some health conditions
265
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2342
ゲノムの遺伝子より
12:18
than every single gene in your genome.
266
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3665
健康には大切なのかもしれません
12:23
And then in mice, we can do a lot more.
267
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2237
それでマウスを使って 色々研究出来
12:25
So in mice, microbes have been linked
to all kinds of additional conditions,
to all kinds of additional conditions,
268
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3645
多発性硬化症、鬱病、自閉症
12:29
including things like multiple sclerosis,
269
737437
2716
肥満などの多くの疾患と
12:32
depression, autism, and again, obesity.
270
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3738
微生物との関係が明らかとなってきました
12:35
But how can we tell whether
these microbial differences
these microbial differences
271
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2764
でも どうしてどの微生物が
病気の原因となるのか
病気の原因となるのか
12:38
that correlate with disease
are cause or effect?
are cause or effect?
272
746655
2763
保護的役割をするのか
知る事が出来るのでしょう？
知る事が出来るのでしょう？
12:41
Well, one thing we can do
is we can raise some mice
is we can raise some mice
273
749418
2647
こういう事が出来ます
12:44
without any microbes of their own
in a germ-free bubble.
in a germ-free bubble.
274
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2647
マウスを微生物のいない
無菌の環境で育て
無菌の環境で育て
12:46
Then we can add in some microbes
that we think are important,
that we think are important,
275
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2953
その環境に有用微生物と
思われる微生物を加え
思われる微生物を加え
12:49
and see what happens.
276
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2082
どうなるか見ます
12:51
When we take the microbes
from an obese mouse
from an obese mouse
277
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2279
肥満のマウスからの微生物を採り
12:54
and transplant them
into a genetically normal mouse
into a genetically normal mouse
278
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2504
遺伝的に異常のない
12:56
that's been raised in a bubble
with no microbes of its own,
with no microbes of its own,
279
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2859
無菌環境で育てられた
マウスに移植すると
マウスに移植すると
12:59
it becomes fatter than if it got them
from a regular mouse.
from a regular mouse.
280
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3353
同じ微生物を移植された
自然環境のマウスより太ってしまいます
自然環境のマウスより太ってしまいます
13:04
Why this happens
is absolutely amazing, though.
is absolutely amazing, though.
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実に驚くべき出来事です
13:06
Sometimes what's going on
is that the microbes
is that the microbes
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微生物は食餌の消化を助け
13:08
are helping them digest food
more efficiently from the same diet,
more efficiently from the same diet,
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そこから効率よくエネルギーを
13:11
so they're taking more energy
from their food,
from their food,
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取っているという事もありますが
13:13
but other times, the microbes
are actually affecting their behavior.
are actually affecting their behavior.
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実際 宿主の行動に影響を与えているのです
13:17
What they're doing is they're eating
more than the normal mouse,
more than the normal mouse,
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微生物の働きで宿主は普通のマウスより食べ
13:20
so they only get fat if we let them
eat as much as they want.
eat as much as they want.
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そんなマウスに好きなだけ
食べさせたら太るだけです
食べさせたら太るだけです
13:24
So this is really remarkable, right?
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信じられないようなことですね
13:27
The implication is that microbes
can affect mammalian behavior.
can affect mammalian behavior.
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これで微生物はほ乳類の行動に影響する
と言う事が分かります
と言う事が分かります
13:33
So you might be wondering whether we can
also do this sort of thing across species,
also do this sort of thing across species,
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では生物種間でもこうなるのだろうか
という疑問が湧いてくると思います
という疑問が湧いてくると思います
13:37
and it turns out that if you take microbes
from an obese person
from an obese person
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肥満の人の微生物を
13:40
and transplant them into mice
you've raised germ-free,
you've raised germ-free,
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無菌の環境で育ったマウスに移植すると
13:43
those mice will also become fatter
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2090
痩せた人の微生物を
13:45
than if they received the microbes
from a lean person,
from a lean person,
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移植した時より太りましたが
13:48
but we can design a microbial community
that we inoculate them with
that we inoculate them with
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肥満を抑制する微生物を培養して
13:52
that prevents them
from gaining this weight.
from gaining this weight.
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マウスに移植する事もできます
13:55
We can also do this for malnutrition.
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栄養失調に関しても同じ様な研究をしました
13:57
So in a project funded
by the Gates Foundation,
by the Gates Foundation,
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ゲイツ財団の資金を受けたプロジェクトで
14:00
what we're looking at
is children in Malawi
is children in Malawi
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クワシオルコルという栄養失調からくる
14:02
who have kwashiorkor,
a profound form of malnutrition,
a profound form of malnutrition,
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830871
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深刻な疾患を持つ
マラウイの子供達を見ています
マラウイの子供達を見ています
14:05
and mice that get the kwashiorkor
community transplanted into them
community transplanted into them
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833529
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クワシオルコルの微生物叢を
移植されたマウスは
移植されたマウスは
14:08
lose 30 percent of their body mass
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836652
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ほんの３週間で体重が
14:11
in just three weeks,
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839022
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30%減少します
14:12
but we can restore their health by using
the same peanut butter-based supplement
the same peanut butter-based supplement
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840201
3818
これは臨床で子供達に使われている
ピーナッツ原料のサプリを使い
ピーナッツ原料のサプリを使い
14:16
that is used for
the children in the clinic,
the children in the clinic,
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健康を回復させる事ができます
14:18
and the mice that receive the community
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846132
1856
そして双子のクワシオルコルに
罹っていない方の
罹っていない方の
14:19
from the healthy identical twins
of the kwashiorkor children do fine.
of the kwashiorkor children do fine.
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847988
3247
健康な子どもからの微生物叢を
移植したマウスには問題はありません
移植したマウスには問題はありません
14:24
This is truly amazing because it suggests
that we can pilot therapies
that we can pilot therapies
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852035
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これは本当にすごいことです
なぜならヒト腸内細菌叢をマウスで試し
なぜならヒト腸内細菌叢をマウスで試し
14:27
by trying them out
in a whole bunch of different mice
in a whole bunch of different mice
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その結果 自由に操作して
個別化された治療法を
個別化された治療法を
14:30
with individual people's gut communities
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858483
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生み出せるかもしれないという事を
14:32
and perhaps tailor those therapies
all the way down to the individual level.
all the way down to the individual level.
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4599
示唆しているからです
14:38
So I think it's really important
that everyone has a chance
that everyone has a chance
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2915
それで人々がこの発見に参加することは
14:41
to participate in this discovery.
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869177
2706
本当に大切だと思い
数年前 こういう事を始めました
14:43
So, a couple of years ago,
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871883
1248
14:45
we started this project
called American Gut,
called American Gut,
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873131
2071
「アメリカの消化器官」
と呼ばれるプロジェクトで
と呼ばれるプロジェクトで
14:47
which allows you to claim a place
for yourself on this microbial map.
for yourself on this microbial map.
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875202
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微生物分布図のどこに自分がいるのか
見れるようになったのです
見れるようになったのです
14:51
This is now the largest crowd-funded
science project that we know of --
science project that we know of --
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879406
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これは最大のクラウドファンディングによる
科学プロジェクトで
科学プロジェクトで
14:54
over 8,000 people
have signed up at this point.
have signed up at this point.
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この時点で8,000人以上の
人々が登録しています
人々が登録しています
14:57
What happens is,
they send in their samples,
they send in their samples,
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885651
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運営の仕方は まず試料が送られて来
15:00
we sequence the DNA of their microbes
and then release the results back to them.
and then release the results back to them.
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888229
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その人の微生物のDNAが配列され
その本人にそれが送られます
その本人にそれが送られます
15:04
We also release them, de-identified,
to scientists, to educators,
to scientists, to educators,
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892014
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それは匿名で科学者 教育関係者
15:07
to interested members
of the general public, and so forth,
of the general public, and so forth,
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3019
興味のある一般の人々にも公表し
15:10
so anyone can have access to the data.
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898724
3155
誰でもそのデータに
アクセスできるようにします
アクセスできるようにします
15:13
On the other hand,
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901879
1171
また 同時に
15:15
when we do tours of our lab
at the BioFrontiers Institute,
at the BioFrontiers Institute,
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バイオフロンティア協会の
研究室を見学する人々に
研究室を見学する人々に
15:18
and we explain that we use robots
and lasers to look at poop,
and lasers to look at poop,
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906332
3560
糞便を見るのにロボットやレーザーを
使う事を説明したりしています
使う事を説明したりしています
15:21
it turns out that not
everyone wants to know.
everyone wants to know.
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909892
3112
別に誰もが知りたい事ではないようですが
15:25
(Laughter)
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913004
1282
（笑）
15:26
But I'm guessing that many of you do,
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914286
1921
でも皆様はそうでないだろうと思い
15:28
and so I brought some kits here
if you're interested
if you're interested
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916207
2659
キットをいくらか持ってきましたので
15:30
in trying this out for yourself.
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2730
もし関心がおありなら どうぞお試し下さい
15:35
So why might we want to do this?
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923046
1947
こんな事をする理由は
15:36
Well, it turns out that microbes
are not just important
are not just important
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924993
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微生物は健康状態を見るのに
15:39
for finding out where we are
in terms of our health,
in terms of our health,
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2901
重要だと言うだけでなく 実際に病気を
15:42
but they can actually cure disease.
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930464
2408
治す事が分かったからです
15:44
This is one of the newest things
we've been able to visualize
we've been able to visualize
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932872
2925
これはごく最近ミネソタ大学で我々が
15:47
with colleagues
at the University of Minnesota.
at the University of Minnesota.
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935797
2739
考えてきた可能性の１つです
15:50
So here's that map
of the human microbiome again.
of the human microbiome again.
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938536
2617
もう一度 ヒト微生物の分布図を
15:53
What we're looking at now --
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941153
1457
ご覧になると・・・
15:54
I'm going to add in the community
of some people with C. diff.
of some people with C. diff.
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942610
3370
クロストリジウム・ディフィシルを
持つ人の微生物叢を加えます
持つ人の微生物叢を加えます
15:57
So, this is a terrible form of diarrhea
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945980
2279
これは ひどい時は１日に20回も
16:00
where you have to go
up to 20 times a day,
up to 20 times a day,
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948259
2345
下痢をした人からの微生物です
16:02
and these people have failed
antibiotic therapy for two years
antibiotic therapy for two years
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950604
3111
我々の臨床試験に参加できるまで
抗生物質が効かないそんな状態が
抗生物質が効かないそんな状態が
16:05
before they're eligible for this trial.
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953715
2299
２年間続いていた人々からのものです
16:08
So what would happen if we transplanted
some of the stool from a healthy donor,
some of the stool from a healthy donor,
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956014
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では図の下に散らばる健康な人の糞便微生物を
16:12
that star down at the bottom,
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1857
この患者達に移植したら どうなるでしょう
16:14
into these patients.
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1416
この患者達に移植したら どうなるでしょう
16:15
Would the good microbes
do battle with the bad microbes
do battle with the bad microbes
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963700
2609
善玉菌が悪玉菌と戦ってくれ
16:18
and help to restore their health?
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2079
健康が回復するでしょうか
16:20
So let's watch exactly what happens there.
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2316
それがどうなるか見てみましょう
16:22
Four of those patients
are about to get a transplant
are about to get a transplant
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2516
患者の中の４人が 今 健康な人からの
16:25
from that healthy donor at the bottom,
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移植を受け取る寸前です
16:27
and what you can see is that immediately,
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1957
そして移植されたかと思うと
16:29
you have this radical change
in the gut community.
in the gut community.
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瞬く間に腸内細菌叢に劇的変化が現れます
16:31
So one day after you do that transplant,
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この移植の翌日
16:33
all those symptoms clear up,
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981555
1649
患者はすっかり回復し
16:35
the diarrhea vanishes,
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983204
1555
下痢の症状は消えました
16:36
and they're essentially healthy again,
coming to resemble the donor's community,
coming to resemble the donor's community,
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984759
3772
４人は根本的に健康を取り戻し
微生物叢は健康な提供者のそれに似て
微生物叢は健康な提供者のそれに似て
16:40
and they stay there.
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今この下に位置しています
16:42
(Applause)
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4797
（拍手）
16:49
So we're just at the beginning
of this discovery.
of this discovery.
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2375
この旅は始まったばかりです
16:51
We're just finding out that microbes
have implications
have implications
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2540
微生物の炎症性腸疾患から肥満まで
16:54
for all these different kinds of diseases,
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2173
あらゆる病気との関係
16:56
ranging from inflammatory
bowel disease to obesity,
bowel disease to obesity,
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2468
また自閉症や鬱病さえとの関連を
16:58
and perhaps even autism and depression.
365
1006846
3083
研究している段階です
17:01
What we need to do, though,
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しかし我々は
17:03
is we need to develop
a kind of microbial GPS,
a kind of microbial GPS,
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2258
微生物叢の現在地点だけでなく
17:05
where we don't just know
where we are currently
where we are currently
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2321
これから行くべき方向に向かうには
何をすべきかを
何をすべきかを
17:07
but also where we want to go
and what we need to do
and what we need to do
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知る為に微生物GPSのような物を
17:11
in order to get there,
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開発する必要があり
17:12
and we need to be able
to make this simple enough
to make this simple enough
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2345
又これを子供でも使えるような
17:15
that even a child can use it.
(Laughter)
(Laughter)
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2601
簡単なものにする必要があります
（笑）
（笑）
17:17
Thank you.
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ありがとうございました
17:20
(Applause)
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3204
（拍手）
ABOUT THE SPEAKER
Rob Knight - Microbial ecologistRob Knight explores the unseen microbial world that exists literally right under our noses -- and everywhere else on (and in) our bodies.
Why you should listen
Using scatological research methods that might repel the squeamish, microbial researcher Rob Knight uncovers the secret ecosystem (or "microbiome") of microbes that inhabit our bodies -- and the bodies of every creature on earth. In the process, he’s discovered a complex internal ecology that affects everything from weight loss to our susceptibility to disease. As he said to Nature in 2012, "What motivates me, from a pragmatic standpoint, is how understanding the microbial world might help us improve human and environmental health.”
Knight’s recent projects include the American Gut, an attempt to map the unique microbiome of the United States using open-access data mining tools and citizen-scientists to discover how lifestyle and diet affect our internal flora and fauna, and our overall health.
Knight is the author of the TED Book, Follow Your Gut: The Enormous Impact of Tiny Microbes.
Rob Knight | Speaker | TED.com