ABOUT THE SPEAKER
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.

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

More profile about the speaker
Rob Knight | Speaker | TED.com
TED2014

Rob Knight: How our microbes make us who we are

Filmed:
2,014,096 views

Rob Knight is a pioneer in studying human microbes, the community of tiny single-cell organisms living inside our bodies that have a huge — and largely unexplored — role in our health. “The three pounds of microbes that you carry around with you might be more important than every single gene you carry around in your genome,” he says. Find out why.
- 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

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,
0
1089
3980
00:17
but we haven't always been that good
at figuring out what's important.
1
5069
4216
00:21
Take the ancient Egyptians, for example:
2
9285
2392
00:23
very concerned about the body parts
they thought they'd need in the afterlife,
3
11677
3947
00:27
but they left some parts out.
4
15624
2090
00:29
This part, for example.
5
17714
2623
00:32
Although they very carefully
preserved the stomach, the lungs,
6
20337
2997
00:35
the liver, and so forth,
7
23334
1165
00:36
they just mushed up the brain,
drained it out through the nose,
8
24499
3036
00:39
and threw it away,
9
27535
1724
00:41
which makes sense, really,
10
29259
1341
00:42
because what does a brain
do for us anyway?
11
30600
2009
00:45
But imagine if there were a kind
of neglected organ in our bodies
12
33439
3198
00:48
that weighed just as much as the brain
13
36637
2136
00:50
and in some ways was just
as important to who we are,
14
38773
2926
00:53
but we knew so little about
and treated with such disregard.
15
41699
3552
00:57
And imagine if,
through new scientific advances,
16
45251
2903
01:00
we were just beginning to understand
17
48154
1741
01:01
its importance to how
we think of ourselves.
18
49895
2902
01:04
Wouldn't you want to know more about it?
19
52797
2206
01:07
Well, it turns out that we do
have something just like that:
20
55003
3226
01:10
our gut,
21
58959
1682
01:12
or rather, its microbes.
22
60641
2662
01:15
But it's not just the microbes
in our gut that are important.
23
63303
2893
01:18
Microbes all over our body
24
66196
1508
01:19
turn out to be really critical
to a whole range of differences
25
67704
2913
01:22
that make different people who we are.
26
70617
2497
01:25
So for example, have you ever noticed
27
73114
2314
01:27
how some people get bitten by mosquitos
way more often than others?
28
75428
4183
01:31
It turns out that everyone's anecdotal
experience out camping is actually true.
29
79611
4579
01:36
For example, I seldom
get bitten by mosquitos,
30
84190
2809
01:38
but my partner Amanda
attracts them in droves,
31
86999
2277
01:41
and the reason why is that we have
different microbes on our skin
32
89276
3063
01:44
that produce different chemicals
that the mosquitos detect.
33
92339
3722
01:48
Now, microbes are also really important
in the field of medicine.
34
96061
3506
01:51
So, for example, what microbes
you have in your gut
35
99567
2465
01:54
determine whether particular painkillers
are toxic to your liver.
36
102032
4462
01:58
They also determine whether or not other
drugs will work for your heart condition.
37
106494
4245
02:02
And, if you're a fruit fly, at least,
38
110739
2687
02:05
your microbes determine
who you want to have sex with.
39
113426
3182
02:08
We haven't demonstrated this in humans yet
40
116608
2159
02:10
but maybe it's just a matter of time
before we find out. (Laughter)
41
118767
4296
02:15
So microbes are performing
a huge range of functions.
42
123063
2623
02:17
They help us digest our food.
43
125686
1766
02:19
They help educate our immune system.
44
127452
2274
02:21
They help us resist disease,
45
129726
1950
02:23
and they may even
be affecting our behavior.
46
131676
2508
02:26
So what would a map of all these
microbial communities look like?
47
134184
3947
02:30
Well, it wouldn't look exactly like this,
48
138131
2276
02:32
but it's a helpful guide
for understanding biodiversity.
49
140407
2879
02:35
Different parts of the world
have different landscapes of organisms
50
143286
3924
02:39
that are immediately characteristic
of one place or another
51
147210
4571
02:43
or another.
52
151781
2037
02:45
With microbiology, it's kind of the same,
although I've got to be honest with you:
53
153818
3865
02:49
All the microbes essentially
look the same under a microscope.
54
157683
3103
02:52
So instead of trying
to identify them visually,
55
160786
2529
02:55
what we do is we look
at their DNA sequences,
56
163315
2486
02:57
and in a project called
the Human Microbiome Project,
57
165801
2924
03:00
NIH funded this $173 million project
58
168725
3339
03:04
where hundreds
of researchers came together
59
172064
2409
03:06
to map out all the A's, T's, G's, and C's,
60
174473
2779
03:09
and all of these microbes
in the human body.
61
177252
2176
03:11
So when we take them together,
they look like this.
62
179428
3361
03:14
It's a bit more difficult
to tell who lives where now, isn't it?
63
182789
3931
03:18
What my lab does is develop
computational techniques that allow us
64
186720
3548
03:22
to take all these terabytes
of sequence data
65
190268
2611
03:24
and turn them into something
that's a bit more useful as a map,
66
192879
3013
03:27
and so when we do that
with the human microbiome data
67
195892
2753
03:30
from 250 healthy volunteers,
68
198645
2095
03:32
it looks like this.
69
200740
2644
03:35
Each point here represents
all the complex microbes
70
203384
3180
03:38
in an entire microbial community.
71
206564
2183
03:40
See, I told you they basically
all look the same.
72
208747
2330
03:43
So what we're looking at is each point
represents one microbial community
73
211077
3889
03:46
from one body site
of one healthy volunteer.
74
214966
2260
03:49
And so you can see that there's different
parts of the map in different colors,
75
217226
3796
03:53
almost like separate continents.
76
221022
1799
03:54
And what it turns out to be
77
222821
1458
03:56
is that those, as the different
regions of the body,
78
224279
2440
03:58
have very different microbes in them.
79
226719
2078
04:00
So what we have is we have
the oral community up there in green.
80
228797
3683
04:04
Over on the other side,
we have the skin community in blue,
81
232480
2814
04:07
the vaginal community in purple,
82
235294
2287
04:09
and then right down at the bottom,
we have the fecal community in brown.
83
237581
3701
04:13
And we've just over the last few years
84
241416
1883
04:15
found out that the microbes
in different parts of the body
85
243299
2799
04:18
are amazingly different from one another.
86
246098
2198
04:20
So if I look at just one person's microbes
87
248296
2832
04:23
in the mouth and in the gut,
88
251128
2114
04:25
it turns out that the difference between
those two microbial communities
89
253242
3460
04:28
is enormous.
90
256702
1531
04:30
It's bigger than the difference
between the microbes in this reef
91
258233
3165
04:33
and the microbes in this prairie.
92
261398
2733
04:36
So this is incredible
when you think about it.
93
264131
2531
04:38
What it means is that a few feet
of difference in the human body
94
266662
3366
04:42
makes more of a difference
to your microbial ecology
95
270028
2694
04:44
than hundreds of miles on Earth.
96
272722
2245
04:46
And this is not to say that two people
look basically the same
97
274967
3020
04:49
in the same body habitat, either.
98
277987
1852
04:51
So you probably heard
99
279839
1606
04:53
that we're pretty much all the same
in terms of our human DNA.
100
281445
3008
04:56
You're 99.99 percent identical
in terms of your human DNA
101
284453
4089
05:00
to the person sitting next to you.
102
288542
1867
05:02
But that's not true of your gut microbes:
103
290409
2242
05:04
you might only share 10 percent similarity
104
292651
2487
05:07
with the person sitting next to you
in terms of your gut microbes.
105
295138
3510
05:10
So that's as different
as the bacteria on this prairie
106
298648
2796
05:13
and the bacteria in this forest.
107
301444
2056
05:16
So these different microbes
108
304460
1449
05:17
have all these different kinds
of functions that I told you about,
109
305909
3167
05:21
everything from digesting food
110
309076
1696
05:22
to involvement
in different kinds of diseases,
111
310772
2555
05:25
metabolizing drugs, and so forth.
112
313327
1866
05:27
So how do they do all this stuff?
113
315193
2106
05:29
Well, in part it's because
114
317299
1896
05:31
although there's just three pounds
of those microbes in our gut,
115
319195
3330
05:34
they really outnumber us.
116
322525
1760
05:36
And so how much do they outnumber us?
117
324285
2220
05:38
Well, it depends on what
you think of as our bodies.
118
326505
3112
05:41
Is it our cells?
119
329617
1485
05:43
Well, each of us consists
of about 10 trillion human cells,
120
331102
3413
05:46
but we harbor as many
as 100 trillion microbial cells.
121
334515
3231
05:49
So they outnumber us 10 to one.
122
337746
2774
05:52
Now, you might think, well,
we're human because of our DNA,
123
340520
3911
05:56
but it turns out that each of us has
about 20,000 human genes,
124
344431
3321
05:59
depending on what you count exactly,
125
347752
1956
06:01
but as many as two million
to 20 million microbial genes.
126
349708
4492
06:06
So whichever way we look at it,
we're vastly outnumbered
127
354200
2759
06:08
by our microbial symbionts.
128
356959
2832
06:11
And it turns out that in addition
to traces of our human DNA,
129
359791
3227
06:15
we also leave traces
of our microbial DNA
130
363018
2227
06:17
on everything we touch.
131
365245
1780
06:19
We showed in a study a few years ago
132
367025
1792
06:20
that you can actually match
the palm of someone's hand up
133
368817
2795
06:23
to the computer mouse
that they use routinely
134
371612
2277
06:25
with up to 95 percent accuracy.
135
373889
2297
06:28
So this came out in a scientific journal
a few years ago,
136
376186
2856
06:31
but more importantly,
it was featured on "CSI: Miami,"
137
379042
2553
06:33
so you really know it's true.
138
381595
1787
06:35
(Laughter)
139
383382
1595
06:36
So where do our microbes
come from in the first place?
140
384977
3397
06:40
Well if, as I do, you have dogs or kids,
141
388374
2647
06:43
you probably have
some dark suspicions about that,
142
391021
2363
06:45
all of which are true, by the way.
143
393384
1979
06:47
So just like we can match
you to your computer equipment
144
395363
2758
06:50
by the microbes you share,
145
398121
1703
06:51
we can also match you up to your dog.
146
399824
2208
06:54
But it turns out that in adults,
147
402032
2107
06:56
microbial communities
are relatively stable,
148
404139
2299
06:58
so even if you live together with someone,
149
406438
2134
07:00
you'll maintain your separate
microbial identity
150
408572
2398
07:02
over a period of weeks,
months, even years.
151
410970
3014
07:05
It turns out that our
first microbial communities
152
413984
2891
07:08
depend a lot on how we're born.
153
416875
2150
07:11
So babies that come out
the regular way,
154
419025
2181
07:13
all of their microbes are basically
like the vaginal community,
155
421206
3060
07:16
whereas babies that are
delivered by C-section,
156
424266
2365
07:18
all of their microbes instead
look like skin.
157
426631
2906
07:21
And this might be associated
with some of the differences
158
429537
3037
07:24
in health associated with Cesarean birth,
159
432574
2788
07:27
such as more asthma, more allergies,
even more obesity,
160
435362
3216
07:30
all of which have been linked
to microbes now,
161
438578
2530
07:33
and when you think about it,
until recently, every surviving mammal
162
441108
3897
07:37
had been delivered by the birth canal,
163
445005
2556
07:39
and so the lack
of those protective microbes
164
447561
2276
07:41
that we've co-evolved with
might be really important
165
449837
2450
07:44
for a lot of these different conditions
that we now know involve the microbiome.
166
452287
4509
07:48
When my own daughter was born
a couple of years ago
167
456796
2737
07:51
by emergency C-section,
168
459533
2435
07:53
we took matters into our own hands
169
461968
1841
07:55
and made sure she was coated
with those vaginal microbes
170
463809
2680
07:58
that she would have gotten naturally.
171
466489
2040
08:00
Now, it's really difficult to tell
whether this has had an effect
172
468529
3384
08:03
on her health specifically, right?
173
471913
2002
08:05
With a sample size of just one child,
no matter how much we love her,
174
473915
3681
08:09
you don't really have
enough of a sample size
175
477596
2217
08:11
to figure out what happens on average,
176
479813
1946
08:13
but at two years old,
she hasn't had an ear infection yet,
177
481759
2897
08:16
so we're keeping our fingers
crossed on that one.
178
484656
2285
08:18
And what's more, we're starting
to do clinical trials with more children
179
486941
3457
08:22
to figure out whether
this has a protective effect generally.
180
490398
2922
08:27
So how we're born has a tremendous effect
on what microbes we have initially,
181
495031
5323
08:32
but where do we go after that?
182
500354
1917
08:34
What I'm showing you
again here is this map
183
502271
2270
08:36
of the Human Microbiome Project Data,
184
504541
1998
08:38
so each point represents
a sample from one body site
185
506539
2763
08:41
from one of 250 healthy adults.
186
509302
2540
08:43
And you've seen children
develop physically.
187
511842
2067
08:45
You've seen them develop mentally.
188
513909
2056
08:47
Now, for the first time,
you're going to see
189
515965
2075
08:50
one of my colleague's children
develop microbially.
190
518040
3358
08:53
So what we are going to look at
191
521398
1565
08:54
is we're going to look
at this one baby's stool,
192
522963
2687
08:57
the fecal community,
which represents the gut,
193
525650
2449
09:00
sampled every week
for almost two and a half years.
194
528099
3169
09:03
And so we're starting on day one.
195
531268
1663
09:04
What's going to happen is that the infant
is going to start off as this yellow dot,
196
532931
3918
09:08
and you can see that he's starting off
basically in the vaginal community,
197
536849
3480
09:12
as we would expect from his delivery mode.
198
540329
2026
09:14
And what's going to happen
over these two and a half years
199
542355
2714
09:17
is that he's going to travel
all the way down
200
545069
2142
09:19
to resemble the adult fecal community from
healthy volunteers down at the bottom.
201
547211
3814
09:23
So I'm just going to start this going
and we'll see how that happens.
202
551025
3348
09:26
What you can see, and remember
each step in this is just one week,
203
554913
4036
09:30
what you can see is that week to week,
204
558949
1866
09:32
the change in the microbial community
of the feces of this one child,
205
560815
4683
09:37
the differences week to week
are much greater
206
565498
2551
09:40
than the differences between
individual healthy adults
207
568049
2531
09:42
in the Human Microbiome Project cohort,
208
570580
1950
09:44
which are those brown dots
down at the bottom.
209
572530
2476
09:47
And you can see he's starting
to approach the adult fecal community.
210
575006
3197
09:50
This is up to about two years.
211
578203
1515
09:51
But something amazing
is about to happen here.
212
579718
2170
09:53
So he's getting antibiotics
for an ear infection.
213
581888
3088
09:56
What you can see is
this huge change in the community,
214
584976
2554
09:59
followed by a relatively rapid recovery.
215
587530
2058
10:01
I'll just rewind that for you.
216
589588
2182
10:05
And what we can see is that
just over these few weeks,
217
593340
3589
10:08
we have a much more radical change,
218
596929
1933
10:10
a setback of many months
of normal development,
219
598862
2530
10:13
followed by a relatively rapid recovery,
220
601392
2252
10:15
and by the time he reaches day 838,
221
603644
4133
10:19
which is the end of this video,
222
607777
1719
10:21
you can see that he has essentially
reached the healthy adult stool community,
223
609496
3697
10:25
despite that antibiotic intervention.
224
613193
2448
10:27
So this is really interesting
because it raises fundamental questions
225
615641
3328
10:30
about what happens when we intervene
at different ages in a child's life.
226
618969
4099
10:35
So does what we do early on, where
the microbiome is changing so rapidly,
227
623068
3611
10:38
actually matter,
228
626679
1300
10:39
or is it like throwing a stone
into a stormy sea,
229
627979
2483
10:42
where the ripples will just be lost?
230
630462
1742
10:45
Well, fascinatingly, it turns out
that if you give children antibiotics
231
633044
4291
10:49
in the first six months of life,
232
637335
1650
10:50
they're more likely
to become obese later on
233
638985
2785
10:53
than if they don't get antibiotics then
or only get them later,
234
641770
3127
10:56
and so what we do early on
may have profound impacts
235
644897
2946
10:59
on the gut microbial community
and on later health
236
647843
3497
11:03
that we're only beginning to understand.
237
651340
2326
11:05
So this is fascinating, because one day,
in addition to the effects
238
653666
4156
11:09
that antibiotics have
on antibiotic-resistant bacteria,
239
657822
2646
11:12
which are very important,
240
660468
1696
11:14
they may also be degrading
our gut microbial ecosystems,
241
662164
2903
11:17
and so one day we may come
to regard antibiotics with the same horror
242
665067
3272
11:20
that we currently reserve
for those metal tools
243
668339
2463
11:22
that the Egyptians used to use
to mush up the brains
244
670802
2459
11:25
before they drained them out
for embalming.
245
673261
2064
11:27
So I mentioned that microbes
have all these important functions,
246
675325
3021
11:30
and they've also now,
just over the past few years,
247
678346
2649
11:32
been connected to a whole range
of different diseases,
248
680995
2833
11:35
including inflammatory bowel disease,
249
683828
2085
11:37
heart disease, colon cancer,
250
685913
1724
11:39
and even obesity.
251
687637
1830
11:41
Obesity has a really
large effect, as it turns out,
252
689467
2646
11:44
and today, we can tell
whether you're lean or obese
253
692113
2393
11:46
with 90 percent accuracy
254
694506
1879
11:48
by looking at the microbes in your gut.
255
696385
2112
11:50
Now, although that might sound impressive,
256
698497
2289
11:52
in some ways it's a little bit problematic
as a medical test,
257
700786
3331
11:56
because you can probably tell
which of these people is obese
258
704117
2997
11:59
without knowing anything
about their gut microbes,
259
707114
2752
12:01
but it turns out that even
if we sequence their complete genomes
260
709866
3043
12:04
and had all their human DNA,
261
712909
1657
12:06
we could only predict which one
was obese with about 60 percent accuracy.
262
714566
4366
12:10
So that's amazing, right?
263
718932
1374
12:12
What it means that the three pounds
of microbes that you carry around with you
264
720306
3812
12:16
may be more important
for some health conditions
265
724118
2342
12:18
than every single gene in your genome.
266
726460
3665
12:23
And then in mice, we can do a lot more.
267
731555
2237
12:25
So in mice, microbes have been linked
to all kinds of additional conditions,
268
733792
3645
12:29
including things like multiple sclerosis,
269
737437
2716
12:32
depression, autism, and again, obesity.
270
740153
3738
12:35
But how can we tell whether
these microbial differences
271
743891
2764
12:38
that correlate with disease
are cause or effect?
272
746655
2763
12:41
Well, one thing we can do
is we can raise some mice
273
749418
2647
12:44
without any microbes of their own
in a germ-free bubble.
274
752065
2647
12:46
Then we can add in some microbes
that we think are important,
275
754712
2953
12:49
and see what happens.
276
757665
2082
12:51
When we take the microbes
from an obese mouse
277
759747
2279
12:54
and transplant them
into a genetically normal mouse
278
762026
2504
12:56
that's been raised in a bubble
with no microbes of its own,
279
764530
2859
12:59
it becomes fatter than if it got them
from a regular mouse.
280
767389
3353
13:04
Why this happens
is absolutely amazing, though.
281
772142
2319
13:06
Sometimes what's going on
is that the microbes
282
774461
2200
13:08
are helping them digest food
more efficiently from the same diet,
283
776661
3058
13:11
so they're taking more energy
from their food,
284
779719
2204
13:13
but other times, the microbes
are actually affecting their behavior.
285
781923
3231
13:17
What they're doing is they're eating
more than the normal mouse,
286
785154
3040
13:20
so they only get fat if we let them
eat as much as they want.
287
788194
3170
13:24
So this is really remarkable, right?
288
792614
2686
13:27
The implication is that microbes
can affect mammalian behavior.
289
795300
4364
13:33
So you might be wondering whether we can
also do this sort of thing across species,
290
801224
4158
13:37
and it turns out that if you take microbes
from an obese person
291
805382
3270
13:40
and transplant them into mice
you've raised germ-free,
292
808652
3063
13:43
those mice will also become fatter
293
811715
2090
13:45
than if they received the microbes
from a lean person,
294
813805
3041
13:48
but we can design a microbial community
that we inoculate them with
295
816846
3345
13:52
that prevents them
from gaining this weight.
296
820191
2554
13:55
We can also do this for malnutrition.
297
823545
2055
13:57
So in a project funded
by the Gates Foundation,
298
825600
3088
14:00
what we're looking at
is children in Malawi
299
828688
2183
14:02
who have kwashiorkor,
a profound form of malnutrition,
300
830871
2658
14:05
and mice that get the kwashiorkor
community transplanted into them
301
833529
3123
14:08
lose 30 percent of their body mass
302
836652
2370
14:11
in just three weeks,
303
839022
1179
14:12
but we can restore their health by using
the same peanut butter-based supplement
304
840201
3818
14:16
that is used for
the children in the clinic,
305
844019
2113
14:18
and the mice that receive the community
306
846132
1856
14:19
from the healthy identical twins
of the kwashiorkor children do fine.
307
847988
3247
14:24
This is truly amazing because it suggests
that we can pilot therapies
308
852035
3941
14:27
by trying them out
in a whole bunch of different mice
309
855976
2507
14:30
with individual people's gut communities
310
858483
1930
14:32
and perhaps tailor those therapies
all the way down to the individual level.
311
860413
4599
14:38
So I think it's really important
that everyone has a chance
312
866262
2915
14:41
to participate in this discovery.
313
869177
2706
14:43
So, a couple of years ago,
314
871883
1248
14:45
we started this project
called American Gut,
315
873131
2071
14:47
which allows you to claim a place
for yourself on this microbial map.
316
875202
4204
14:51
This is now the largest crowd-funded
science project that we know of --
317
879406
3357
14:54
over 8,000 people
have signed up at this point.
318
882763
2888
14:57
What happens is,
they send in their samples,
319
885651
2578
15:00
we sequence the DNA of their microbes
and then release the results back to them.
320
888229
3785
15:04
We also release them, de-identified,
to scientists, to educators,
321
892014
3691
15:07
to interested members
of the general public, and so forth,
322
895705
3019
15:10
so anyone can have access to the data.
323
898724
3155
15:13
On the other hand,
324
901879
1171
15:15
when we do tours of our lab
at the BioFrontiers Institute,
325
903050
3282
15:18
and we explain that we use robots
and lasers to look at poop,
326
906332
3560
15:21
it turns out that not
everyone wants to know.
327
909892
3112
15:25
(Laughter)
328
913004
1282
15:26
But I'm guessing that many of you do,
329
914286
1921
15:28
and so I brought some kits here
if you're interested
330
916207
2659
15:30
in trying this out for yourself.
331
918866
2730
15:35
So why might we want to do this?
332
923046
1947
15:36
Well, it turns out that microbes
are not just important
333
924993
2570
15:39
for finding out where we are
in terms of our health,
334
927563
2901
15:42
but they can actually cure disease.
335
930464
2408
15:44
This is one of the newest things
we've been able to visualize
336
932872
2925
15:47
with colleagues
at the University of Minnesota.
337
935797
2739
15:50
So here's that map
of the human microbiome again.
338
938536
2617
15:53
What we're looking at now --
339
941153
1457
15:54
I'm going to add in the community
of some people with C. diff.
340
942610
3370
15:57
So, this is a terrible form of diarrhea
341
945980
2279
16:00
where you have to go
up to 20 times a day,
342
948259
2345
16:02
and these people have failed
antibiotic therapy for two years
343
950604
3111
16:05
before they're eligible for this trial.
344
953715
2299
16:08
So what would happen if we transplanted
some of the stool from a healthy donor,
345
956014
4413
16:12
that star down at the bottom,
346
960427
1857
16:14
into these patients.
347
962284
1416
16:15
Would the good microbes
do battle with the bad microbes
348
963700
2609
16:18
and help to restore their health?
349
966309
2079
16:20
So let's watch exactly what happens there.
350
968388
2316
16:22
Four of those patients
are about to get a transplant
351
970704
2516
16:25
from that healthy donor at the bottom,
352
973220
1904
16:27
and what you can see is that immediately,
353
975124
1957
16:29
you have this radical change
in the gut community.
354
977081
2405
16:31
So one day after you do that transplant,
355
979486
2069
16:33
all those symptoms clear up,
356
981555
1649
16:35
the diarrhea vanishes,
357
983204
1555
16:36
and they're essentially healthy again,
coming to resemble the donor's community,
358
984759
3772
16:40
and they stay there.
359
988531
2062
16:42
(Applause)
360
990593
4797
16:49
So we're just at the beginning
of this discovery.
361
997290
2375
16:51
We're just finding out that microbes
have implications
362
999665
2540
16:54
for all these different kinds of diseases,
363
1002205
2173
16:56
ranging from inflammatory
bowel disease to obesity,
364
1004378
2468
16:58
and perhaps even autism and depression.
365
1006846
3083
17:01
What we need to do, though,
366
1009929
1338
17:03
is we need to develop
a kind of microbial GPS,
367
1011267
2258
17:05
where we don't just know
where we are currently
368
1013525
2321
17:07
but also where we want to go
and what we need to do
369
1015846
3551
17:11
in order to get there,
370
1019397
1486
17:12
and we need to be able
to make this simple enough
371
1020883
2345
17:15
that even a child can use it.
(Laughter)
372
1023228
2601
17:17
Thank you.
373
1025829
2229
17:20
(Applause)
374
1028058
3204

▲Back to top

ABOUT THE SPEAKER
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.

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

More profile about the speaker
Rob Knight | Speaker | TED.com