0:00:06 > 0:00:08The Science Museum in London
0:00:08 > 0:00:12is being prepared for a most peculiar event.
0:00:13 > 0:00:17Here, live, in front of hundreds of people,
0:00:17 > 0:00:21an alien world is about to be explored.
0:00:22 > 0:00:24- Urgh, God! - SQUELCHING
0:00:24 > 0:00:27Keep going and keep going...
0:00:27 > 0:00:30'It will be scrutinised
0:00:30 > 0:00:32'and probed.'
0:00:33 > 0:00:36PEOPLE WINCE
0:00:36 > 0:00:38Our guts.
0:00:39 > 0:00:41A mysterious organ.
0:00:43 > 0:00:44Writhing tubes,
0:00:44 > 0:00:46corrosive acid
0:00:46 > 0:00:50and home to its own unique ecosystem.
0:00:50 > 0:00:51Mmm!
0:00:51 > 0:00:54'Its dirty work, normally invisible,
0:00:54 > 0:00:59'is about to be laid bare in all its gruesome detail.'
0:00:59 > 0:01:02Oh, God! That is horrible.
0:01:05 > 0:01:07'And the guinea pig for this?
0:01:09 > 0:01:12'Well, that'll be me.'
0:01:12 > 0:01:13During my medical training
0:01:13 > 0:01:16and more recently, as a television presenter,
0:01:16 > 0:01:19I have taken part in some pretty bizarre and painful experiments,
0:01:19 > 0:01:21but nothing quite like this.
0:01:38 > 0:01:42'There's a new attraction at the Science Museum today.
0:01:42 > 0:01:44'My stomach is going on display
0:01:44 > 0:01:46'to be experimented on.
0:01:48 > 0:01:53'I want to explore just how strange our digestive system is.
0:01:53 > 0:01:55'Outside our conscious control,
0:01:55 > 0:01:59'what's going on in this unfamiliar, weird world?
0:01:59 > 0:02:05'Guiding me through is gut expert Dr Mark McAlindon.'
0:02:05 > 0:02:07- Hi, Mark.- Hi, Michael. Nice to meet you.- And you.
0:02:07 > 0:02:10- It's a very theatrical setting, isn't it?- It is.
0:02:10 > 0:02:13It's not a conventional medical environment, but there we go.
0:02:13 > 0:02:15- I think we'll have some fun today. - I think so too.
0:02:15 > 0:02:17- Right, so what happens next?- OK,
0:02:17 > 0:02:20- so first of all, stick this one in. - Ooh, cold.
0:02:22 > 0:02:26'Mark is going to monitor me as I eat a typical day's food.
0:02:26 > 0:02:29'And we'll all watch what happens as it goes on its merry way.'
0:02:34 > 0:02:35These lucky visitors
0:02:35 > 0:02:39will see parts of me that have never been seen before.
0:02:39 > 0:02:42- Perhaps I could ask you to put that over your head.- Sure.
0:02:45 > 0:02:50'We're using the very latest technology,
0:02:50 > 0:02:52'a miniature camera inside a pill.'
0:02:55 > 0:02:58It will, hopefully, travel through me
0:02:58 > 0:03:02and transmit live pictures from the depths of my guts.
0:03:05 > 0:03:11'And as it goes, I'm going to take part in a number of tests.
0:03:11 > 0:03:13'It's a leap into the unknown.
0:03:13 > 0:03:16'We'll be trying things today that few have tried before.'
0:03:16 > 0:03:19Lie down, we'll just do your pulse and blood pressure.
0:03:19 > 0:03:23Ooh, elegant chaise longue here.
0:03:23 > 0:03:26There is one, which is just as well,
0:03:26 > 0:03:28which means you're as fit as a fiddle, fit to go.
0:03:28 > 0:03:30Marvellous. Fit to swallow pills.
0:03:33 > 0:03:38Once swallowed, I'll have no control of the camera.
0:03:38 > 0:03:43The murky world of my intestines is a law unto itself
0:03:43 > 0:03:47and how long it will take the camera to work its way through
0:03:47 > 0:03:49is anybody's guess.
0:03:50 > 0:03:51Um...
0:03:51 > 0:03:53- Um...- Hmm...- Uh...
0:03:54 > 0:03:5616 hours.
0:03:56 > 0:03:58- 30 hours?- Two days?
0:03:58 > 0:04:00- Depends what you've eaten, really, doesn't it?- 24 hours?
0:04:00 > 0:04:02- 12 hours.- A few days.
0:04:02 > 0:04:04- One day.- Two days?
0:04:04 > 0:04:06Two hours?
0:04:10 > 0:04:14Food can take up to three days to travel through the gut,
0:04:14 > 0:04:19but last night, I drank four litres of laxative to clear the way,
0:04:19 > 0:04:23so I'm expecting my camera to travel rather more quickly than that.
0:04:23 > 0:04:26OK, Michael, well, I'd give you the pill camera.
0:04:28 > 0:04:31And if you'd like to take it out of its holder,
0:04:31 > 0:04:34- if I can actually manage that. - Right, OK.
0:04:41 > 0:04:44'This pill houses a mini film crew,
0:04:44 > 0:04:47'complete with lights and camera.
0:04:47 > 0:04:50'It will take pictures three times a second
0:04:50 > 0:04:54'and transmit them to screens here in the Science Museum
0:04:54 > 0:04:56'via sensors on my body.'
0:05:01 > 0:05:03- So, Michael, ready when you are.- OK.
0:05:03 > 0:05:07Pop that into your mouth, a few gentle sips of water.
0:05:13 > 0:05:15- Ah! That's it...- That's it gone?
0:05:15 > 0:05:18It's gone! It's gone on its long journey.
0:05:18 > 0:05:20I can't get it back, it's too late.
0:05:32 > 0:05:36'My first feeling is one of relief.
0:05:36 > 0:05:37'The camera is clearly working
0:05:37 > 0:05:40'as it slides down the back of my throat
0:05:40 > 0:05:43'and heads towards my stomach.'
0:05:46 > 0:05:48It's very funny!
0:05:48 > 0:05:50HE LAUGHS
0:06:01 > 0:06:03Propelling the camera down
0:06:03 > 0:06:06are powerful muscles that lie in my gullet or oesophagus.
0:06:09 > 0:06:11Any time you swallow food,
0:06:11 > 0:06:15the oesophagus will be able to tell that there's a force on its wall
0:06:15 > 0:06:18and that initiates the process of contraction of the muscle
0:06:18 > 0:06:19to try and push it further down.
0:06:21 > 0:06:24It's really quite magical.
0:06:24 > 0:06:26So this black hole here,
0:06:26 > 0:06:29soon you'll see the capsule passing into the stomach.
0:06:29 > 0:06:31- Here it goes.- Ooh, there it goes.
0:06:39 > 0:06:43Down here, it's a cavernous, alien landscape.
0:06:44 > 0:06:48And you can see some white blobs of porridge I ate for breakfast.
0:06:50 > 0:06:52But what's really striking
0:06:52 > 0:06:56is there is so much pulsing and throbbing movement going on.
0:06:56 > 0:06:59It's something we're normally completely unaware of
0:06:59 > 0:07:04but it's happening all the time and throughout our digestive system.
0:07:07 > 0:07:10Our guts are a tireless machine
0:07:10 > 0:07:13and I spent a morning in the run-up to this exhibition
0:07:13 > 0:07:15having some scans to find out
0:07:15 > 0:07:18just how the different parts work together.
0:07:24 > 0:07:27I've seen my heart beating...
0:07:27 > 0:07:29my brain buzzing...
0:07:29 > 0:07:32but I have never seen my guts in action.
0:07:32 > 0:07:36Well, lucky me. Today, I get that chance.
0:07:38 > 0:07:40Here at University College Hospital,
0:07:40 > 0:07:44radiologist Stuart Taylor and his team
0:07:44 > 0:07:47are using a stop-motion technique
0:07:47 > 0:07:50to capture the unconscious movement
0:07:50 > 0:07:52involved in a journey through our guts.
0:07:54 > 0:07:56'To get the best-possible images,
0:07:56 > 0:07:59'I'm knocking back a rather disgusting drink.'
0:07:59 > 0:08:03This liquid's got a special sugar in which isn't absorbed by your body,
0:08:03 > 0:08:05so when we do the scan, I'll be able to see
0:08:05 > 0:08:08the inside of the bowel very well and how the bowel works and moves.
0:08:08 > 0:08:11- It's an acquired taste! - It is, probably not something
0:08:11 > 0:08:13you'd to choose drink every day, but hopefully not too bad.
0:08:23 > 0:08:25Michael, I'm going to start a few scans now, OK?
0:08:31 > 0:08:34Breathe in. And hold your breath.
0:08:37 > 0:08:41As I hold my breath, the team takes a series of high-speed images.
0:08:41 > 0:08:43This is the last scan.
0:08:44 > 0:08:47These will be stitched together
0:08:47 > 0:08:49to form a 20-second film of my guts in action.
0:08:49 > 0:08:51All finished. Well done.
0:08:55 > 0:08:57'This technique is normally used
0:08:57 > 0:09:02'to diagnose disorders affecting movement in the gut.'
0:09:02 > 0:09:04That's absolutely fascinating.
0:09:04 > 0:09:08What surprises me is just how much movement there is in here.
0:09:08 > 0:09:09It really is a dance.
0:09:11 > 0:09:15I was lying completely still in the scanner,
0:09:15 > 0:09:19but this slice through my guts shows they were anything but.
0:09:23 > 0:09:26Any food passing through my digestive system
0:09:26 > 0:09:28takes the same route,
0:09:28 > 0:09:33through this pulsating, writhing, continuous tube...
0:09:35 > 0:09:38Down my gullet and into my stomach,
0:09:38 > 0:09:42then into my small intestine, or small bowel.
0:09:44 > 0:09:47Next stop, it's the large intestine,
0:09:47 > 0:09:49otherwise known as the colon.
0:09:52 > 0:09:54And then it's out the other end.
0:09:58 > 0:10:02It's this constant movement throughout our guts
0:10:02 > 0:10:05that enables our bodies to transform food
0:10:05 > 0:10:07into the nutrients that keep us alive.
0:10:15 > 0:10:17'Back here at the Science Museum,
0:10:17 > 0:10:22'the camera has travelled down my gullet and into my stomach,
0:10:22 > 0:10:26'where it's transmitting live pictures to an enthralled audience.
0:10:30 > 0:10:35'Now it's time for some food to start its journey through my guts.
0:10:36 > 0:10:40'And Mark's got something else to view it with.'
0:10:40 > 0:10:42The pill camera is still down in my stomach
0:10:42 > 0:10:44but we're about to stick another camera in,
0:10:44 > 0:10:46which is slightly intimidating-looking.
0:10:46 > 0:10:50It's got a nice...tip there and it's going to go down through my nose,
0:10:50 > 0:10:51which should be fairly unpleasant
0:10:51 > 0:10:55and when it's down there, we'll get a much better look at the stomach
0:10:55 > 0:10:57and then I get to eat a little bit,
0:10:57 > 0:10:59so we can sort of see more of the stomach action.
0:10:59 > 0:11:02- This is going to be a bit uncomfortable, isn't it?- Little bit.
0:11:16 > 0:11:18Urgh, God! Brings tears to your eyes.
0:11:18 > 0:11:22- Ooh, that is uncomfortable. - There we go, there we go.- Oh, dear.
0:11:26 > 0:11:31Although this camera will only go as far as my stomach,
0:11:31 > 0:11:35it is steerable and should give higher-resolution pictures.
0:11:39 > 0:11:42Oh, that was so uncomfortable!
0:11:44 > 0:11:46And there we are into the stomach.
0:11:46 > 0:11:48And there's some porridge from earlier.
0:11:48 > 0:11:50- You OK, Michael?- Yes.
0:11:52 > 0:11:53Ah. Thank you.
0:11:53 > 0:11:55The food has arrived.
0:11:57 > 0:12:00Chicken noodle soup and brightly-coloured veg,
0:12:00 > 0:12:04so we can pick them out when they're inside.
0:12:04 > 0:12:07- I know it's not the perfect position for dining.- No, I can't even see it.
0:12:07 > 0:12:10But would you like to try a little bit of something?
0:12:10 > 0:12:14How about if we go for something with colour?
0:12:14 > 0:12:15OK, something red?
0:12:15 > 0:12:17That sounds good. A few bits.
0:12:19 > 0:12:21- A few bits of yellow?- Yep.
0:12:23 > 0:12:27So we should see it passing by in a minute.
0:12:28 > 0:12:31- Ah, there we go. - Yep, something green went past.
0:12:34 > 0:12:36There might be a little bit of chicken.
0:12:36 > 0:12:40- Oh, there we go. It's coming now.- There it is.
0:12:43 > 0:12:47You can see the way the food is being churned up
0:12:47 > 0:12:49by muscles in my stomach wall.
0:12:49 > 0:12:51As well as this mashing action,
0:12:51 > 0:12:54my stomach is also releasing gastric juices
0:12:54 > 0:12:57and began doing so long before I started eating.
0:12:59 > 0:13:01Gastric juices are released
0:13:01 > 0:13:05at the sight, smell or even thought of food
0:13:05 > 0:13:07and the powerful chemicals they contain
0:13:07 > 0:13:13will help turn these lumps of food into a creamy mush known as chyme.
0:13:13 > 0:13:15Oh, nice.
0:13:20 > 0:13:25But I don't think I can bear having this camera down here any longer.
0:13:25 > 0:13:27Coming back.
0:13:29 > 0:13:30Oh, that's horrible!
0:13:32 > 0:13:35- Back of your nose. - Oh, horrible, horrible, horrible.
0:13:36 > 0:13:38Oh, God! Bloody hell.
0:13:38 > 0:13:41That was horrible. Ah!
0:13:43 > 0:13:45MICHAEL GROANS
0:13:50 > 0:13:54To see my food sloshing around in my gastric juices
0:13:54 > 0:13:56was a novel experience.
0:13:57 > 0:14:00But it wasn't a camera that gave us the first insights
0:14:00 > 0:14:03into the workings of the stomach.
0:14:03 > 0:14:05It was actually a gunshot wound
0:14:05 > 0:14:09that revolutionised our understanding of human digestion.
0:14:14 > 0:14:18Our story starts in June, 1822,
0:14:18 > 0:14:21when a young man is accidentally shot in the chest.
0:14:21 > 0:14:24GUNSHOT ECHOES
0:14:27 > 0:14:32The victim was Canadian boatman Alexis St Martin,
0:14:32 > 0:14:35working on the shores of Lake Michigan.
0:14:35 > 0:14:38The blast ripped through his ribs,
0:14:38 > 0:14:41his lungs and the front wall of his stomach.
0:14:45 > 0:14:49First on the scene was young army doctor William Beaumont.
0:14:49 > 0:14:53He dressed the wound, but really didn't expect his patient to live.
0:14:59 > 0:15:01'But survive he did,
0:15:01 > 0:15:05'and I've come to meet medical historian Lindsey Fitzharris
0:15:05 > 0:15:08'to find out how this unfortunate accident
0:15:08 > 0:15:14'went on to lay the foundations of modern gastroenterology.'
0:15:14 > 0:15:15- Hi.- Hi, Lindsey.
0:15:15 > 0:15:18So this is an actual diagram of the original wound
0:15:18 > 0:15:21and you can see the outline of it. It was really big.
0:15:21 > 0:15:22When St Martin was shot,
0:15:22 > 0:15:26it was about the size of a man's palm, essentially.
0:15:26 > 0:15:29- Wow. That big?- Very big, yes.
0:15:29 > 0:15:32It was on the left side of the chest, right about there.
0:15:32 > 0:15:34We tend to think of the stomach being low
0:15:34 > 0:15:37but it's actually much higher up, right below the diaphragm.
0:15:37 > 0:15:40When he was shot, parts of his undigested breakfast
0:15:40 > 0:15:44began pouring out, along with bits and pieces of his torn stomach,
0:15:44 > 0:15:46but Beaumont's called to the scene
0:15:46 > 0:15:49and over a course of a year, he's able to nurse Alexis back to health
0:15:49 > 0:15:53and what happens to this giant hole is that it shrinks
0:15:53 > 0:15:57and it forms this 2.5-centimetre-diameter fistula.
0:15:57 > 0:16:00Right, so you've got the original hole, size of my palm,
0:16:00 > 0:16:01- and it's shrunk right down.- Yes.
0:16:01 > 0:16:03- But it's still open?- It's still open
0:16:03 > 0:16:07and through that fistula, he can see directly into the stomach.
0:16:07 > 0:16:09It was an incredible opportunity
0:16:09 > 0:16:12for Beaumont to study the living digestive system in a way
0:16:12 > 0:16:15that no other surgeon or physician had been able to do until that point.
0:16:19 > 0:16:23Beaumont certainly made the most of this opportunity.
0:16:25 > 0:16:27Once his patient had recovered,
0:16:27 > 0:16:30he employed him as a handyman
0:16:30 > 0:16:33and studied his stomach for the next ten years.
0:16:36 > 0:16:38He subjects St Martin to a series of experiments.
0:16:40 > 0:16:42And he takes little bags like this
0:16:42 > 0:16:45and he wraps pieces of food in these bags,
0:16:45 > 0:16:47cabbage, meat, all kinds of things,
0:16:47 > 0:16:50and he sticks it directly into that fistula.
0:16:50 > 0:16:53Very nice. So he just pops it into this convenient hole?
0:16:53 > 0:16:56- Pops it into the stomach, yes. - Leaves it there to brew for a while?
0:16:56 > 0:17:00- Exactly.- Like a cup of tea, and then brings it out, inspects it.
0:17:00 > 0:17:01He was very interested
0:17:01 > 0:17:04in how different conditions affected the digestive system -
0:17:04 > 0:17:08for instance, if it was cloudy, if it was sunny, if it was cold.
0:17:11 > 0:17:15As well as putting things into St Martin's stomach,
0:17:15 > 0:17:20Beaumont also sucked out the juices that were produced there.
0:17:24 > 0:17:29And it was these previously-inaccessible bodily fluids
0:17:29 > 0:17:34that were to turn popular beliefs about digestion on their head.
0:17:34 > 0:17:36Did he know what that juice was?
0:17:36 > 0:17:38He didn't at first, but he had it analysed
0:17:38 > 0:17:41and they discovered, of course, what we know today,
0:17:41 > 0:17:44that a lot of it is hydrochloric acid, which is highly corrosive.
0:17:45 > 0:17:50As well as acid, the juices contained digestive enzymes
0:17:50 > 0:17:54and Beaumont discovered he could break down food outside the body
0:17:54 > 0:17:57simply by mixing it with this juice.
0:17:57 > 0:17:59Until then, it was widely believed
0:17:59 > 0:18:02that digestion was purely mechanical.
0:18:02 > 0:18:06But Beaumont showed that the gastric juices
0:18:06 > 0:18:09also had a vital role to play.
0:18:10 > 0:18:12This was a big revelation, presumably?
0:18:12 > 0:18:14Oh, it was a huge paradigm shift.
0:18:14 > 0:18:17I mean, you're going from the mechanical view to the chemical view
0:18:17 > 0:18:20and he was criticised for it back home in America.
0:18:20 > 0:18:23He really achieves his fame afterwards, and today, of course,
0:18:23 > 0:18:25he is known as the father of gastric physiology.
0:18:25 > 0:18:27This is a wonderful story, an extraordinary story.
0:18:27 > 0:18:29It is an extraordinary story
0:18:29 > 0:18:32and one that really changed how we understand the body today.
0:18:44 > 0:18:46Here at the Science Museum,
0:18:46 > 0:18:50I want to demonstrate the power of gastric juices.
0:18:51 > 0:18:54Now we made up a solution here,
0:18:54 > 0:18:58which contains the right balance of acid and also enzymes
0:18:58 > 0:19:01you would find in typical stomach secretions.
0:19:01 > 0:19:04Now, let's check the pH of this one.
0:19:04 > 0:19:07A neutral solution is pH 7.
0:19:07 > 0:19:11Anything less is considered acidic.
0:19:11 > 0:19:13I'm guessing it's going to be around 2.
0:19:13 > 0:19:16I'm expecting something quite acid.
0:19:16 > 0:19:20- Ooh, right. Really incredibly red, isn't it?- Very much so.
0:19:20 > 0:19:24- So that's a 1?- It's a 1, so... - Battery acid?
0:19:24 > 0:19:27Battery acid it would be, absolutely, it's really quite powerful.
0:19:28 > 0:19:33In fact, powerful enough to kill most harmful bacteria
0:19:33 > 0:19:36that might come down into your stomach with your food.
0:19:37 > 0:19:39And take a look at this.
0:19:39 > 0:19:41One of the tests I've always wanted to do,
0:19:41 > 0:19:43I read about this when I was a kid,
0:19:43 > 0:19:46was that if you could drop a coin down into your stomach,
0:19:46 > 0:19:48it would kind of clean it.
0:19:48 > 0:19:50Let's try it and see.
0:19:51 > 0:19:52What I'm surprised by
0:19:52 > 0:19:56is just how robust the lining of your stomach has got to be
0:19:56 > 0:20:00because it's got to put up with acid with a pH of 1.
0:20:00 > 0:20:04Yeah, well, there's a millimetre thick mucus all round the stomach,
0:20:04 > 0:20:06in which there are bicarbonate ions
0:20:06 > 0:20:08which keep it slightly more alkaline,
0:20:08 > 0:20:10so it protects the stomach lining
0:20:10 > 0:20:12from damage from the gastric acid.
0:20:12 > 0:20:14Right. Let's have a look.
0:20:16 > 0:20:18Ooh, yes! Cool!
0:20:18 > 0:20:19I think we see a clear change there.
0:20:19 > 0:20:23So, clearly, the degree of acidity,
0:20:23 > 0:20:26the hydrochloric acid has reacted
0:20:26 > 0:20:31with the compounds on that metal and dissolved them off.
0:20:33 > 0:20:37'That demo has sharpened my appetite.
0:20:37 > 0:20:39'Apart from a small appetiser,
0:20:39 > 0:20:42'it's been a while since I last ate.
0:20:42 > 0:20:46'It's time to test the digestive powers of my own gastric juices
0:20:46 > 0:20:48'with a substantial meal.'
0:20:48 > 0:20:51OK, bring on the food!
0:20:53 > 0:20:55Hooray!
0:20:55 > 0:20:57I have been waiting a long time for this! Thank you.
0:20:57 > 0:21:01So this is the first green thing I've seen for about three days.
0:21:03 > 0:21:05Mmm!
0:21:05 > 0:21:09'It's not the most relaxing place to eat.
0:21:09 > 0:21:13'But that doesn't stop me polishing this off in no time at all.'
0:21:16 > 0:21:17Ah!
0:21:21 > 0:21:26And over the next few hours, my stomach gets to work.
0:21:28 > 0:21:31So this is my stomach having eaten,
0:21:31 > 0:21:35and the picture is very different to when it was empty, isn't it?
0:21:35 > 0:21:38Yeah, it shows what a fantastic job the stomach can do.
0:21:38 > 0:21:40It's really done a blenderiser's job here.
0:21:40 > 0:21:42I think I saw something which was
0:21:42 > 0:21:44probably the beetroot going past as well.
0:21:44 > 0:21:46A sort of red thing. Ooh, there is a great big leaf!
0:21:46 > 0:21:49- There's a leaf there.- And it looks like beetroot there on the top.
0:21:49 > 0:21:52- A bit of pinky stuff. - A bit pinky there.- Yeah.
0:21:52 > 0:21:54The leaves will be a lot of fibrous material,
0:21:54 > 0:21:56which is much more difficult to digest.
0:21:56 > 0:21:58So that may stay that way for a little bit longer,
0:21:58 > 0:22:01whereas the white bits are probably the chips,
0:22:01 > 0:22:03so they're now dissolving in the gastric acid.
0:22:03 > 0:22:07So that's more of a mash of stuff.
0:22:07 > 0:22:08What happened to the steak, then?
0:22:08 > 0:22:12It's interesting that we don't see lumps of meat.
0:22:12 > 0:22:14You would think that that would be the case.
0:22:14 > 0:22:17But the meat will be broken down into fibrous material
0:22:17 > 0:22:19by the action of chewing,
0:22:19 > 0:22:22And then will be acted on by gastric enzymes and gastric acid
0:22:22 > 0:22:23to such an extent
0:22:23 > 0:22:26that you can't actually recognise the meat in the stomach.
0:22:26 > 0:22:30You can recognise the plant material, and some of the carbohydrate,
0:22:30 > 0:22:32the starchy material, but no lumps of meat there.
0:22:35 > 0:22:41With a big meal of steak and chips inside me, my stomach has expanded.
0:22:41 > 0:22:43But by how much?
0:22:43 > 0:22:44What, in size, yeah?
0:22:44 > 0:22:46You answer, darling. I haven't a clue.
0:22:46 > 0:22:48I think it can get REALLY big.
0:22:48 > 0:22:50Probably double in size?
0:22:50 > 0:22:52That much?
0:22:52 > 0:22:53Like this?
0:22:53 > 0:22:54This size?
0:22:54 > 0:22:56This big?
0:22:56 > 0:22:57- HE LAUGHS - No, that's too big!
0:22:57 > 0:22:59- My fist.- A small rugby ball.
0:22:59 > 0:23:00A medium-sized melon.
0:23:00 > 0:23:02I reckon a good...
0:23:02 > 0:23:04I think two litres.
0:23:08 > 0:23:11She's right.
0:23:11 > 0:23:14The average human stomach can expand
0:23:14 > 0:23:17from the size of a small apple when it's empty
0:23:17 > 0:23:20to about two litres when full.
0:23:20 > 0:23:24That's a 40-fold increase.
0:23:24 > 0:23:28And it's now clear that this expandable bag of muscle
0:23:28 > 0:23:33has more subtle and powerful ways to influence how and when we eat
0:23:33 > 0:23:35than was ever previously imagined.
0:23:39 > 0:23:43Father-of-four Bob Laquenpaal rarely feels full,
0:23:43 > 0:23:45no matter what he eats.
0:23:45 > 0:23:47No, I don't want salad.
0:23:50 > 0:23:53'About nine, ten o'clock, I have my first breakfast.
0:23:53 > 0:23:55'A couple of toasts, bowl of cornflakes.
0:23:59 > 0:24:02'Lunchtime is normally a couple chapattis
0:24:02 > 0:24:06'with some chicken or vegetables.
0:24:06 > 0:24:09'After my lunch, if I'm feeling more hungry,
0:24:09 > 0:24:14'I just get a bowl of cornflakes, or Weetabix.'
0:24:14 > 0:24:18In the evening, I'll get some chips, a burger...
0:24:18 > 0:24:21and later on, a chapatti.
0:24:24 > 0:24:28If I'm feeling a bit peckish, I'll buy a big crisp bag,
0:24:28 > 0:24:30- and just munch away. - HE LAUGHS
0:24:30 > 0:24:32I just can't get full.
0:24:34 > 0:24:36- I want to eat everything! - HE LAUGHS
0:24:39 > 0:24:42Bob is almost 20 stone.
0:24:42 > 0:24:45And being so overweight has had serious consequences.
0:24:45 > 0:24:50Six years ago, he had a major health scare.
0:24:50 > 0:24:52I was at home.
0:24:52 > 0:24:55I was lying down, and next minute,
0:24:55 > 0:24:58I'm getting pain in my jaw and in my arm.
0:24:58 > 0:25:00So I thought, "Something's wrong.
0:25:00 > 0:25:02"Let me just drive to the hospital."
0:25:02 > 0:25:06So I drove there, and they said, "You're having a heart attack."
0:25:06 > 0:25:09I was about 28 at the time.
0:25:09 > 0:25:12You're young, I mean, getting a heart attack,
0:25:12 > 0:25:16I was just devastated, yeah.
0:25:17 > 0:25:22Bob tried going on a diet, but couldn't lose enough weight.
0:25:22 > 0:25:26He and his doctors have decided to take more drastic action.
0:25:29 > 0:25:33Bob is about to have a gastric bypass operation.
0:25:33 > 0:25:37The size of his stomach will be radically reduced.
0:25:37 > 0:25:40Now, what are you going to dream about today?
0:25:40 > 0:25:42- BOB CHUCKLES - Mmm?
0:25:42 > 0:25:44BOB CHUCKLES
0:25:47 > 0:25:49His doctors expect the operation
0:25:49 > 0:25:52to have a dramatic effect on his appetite.
0:25:54 > 0:25:57For Bob and his family, it's the best hope
0:25:57 > 0:26:03of bringing about the health changes that he desperately needs.
0:26:03 > 0:26:05- OK, dizzy coming?- Yeah.
0:26:05 > 0:26:07OK. Take three, slow, deep breaths.
0:26:07 > 0:26:10At the end of the third one, things will be much better.
0:26:10 > 0:26:13You're drifting gently off to sleep. Good.
0:26:18 > 0:26:22I'm here at Charing Cross Hospital to watch Bob's surgery.
0:26:27 > 0:26:34His surgeon is leading bariatric consultant Mr Ahmed Ahmed.
0:26:34 > 0:26:38All right. John, are we ready to start?
0:26:38 > 0:26:39He will operate on Bob
0:26:39 > 0:26:43using the latest techniques in keyhole surgery.
0:26:43 > 0:26:47So, I've gone through the skin and the yellow stuff there is fat.
0:26:47 > 0:26:49We have to go through the fat,
0:26:49 > 0:26:52and then through the abdominal wall muscle there.
0:26:52 > 0:26:55The first quick peek inside,
0:26:55 > 0:26:59we're going to see that all the yellow stuff here you see is fat.
0:26:59 > 0:27:04The first stage of the operation is to shrink the size of the stomach.
0:27:04 > 0:27:06That little, pale pink organ coming up,
0:27:06 > 0:27:09that's your stomach, right there.
0:27:09 > 0:27:12And you're essentially going to reduce the size of that?
0:27:12 > 0:27:15- Yes, absolutely. - By what sort of amount?
0:27:15 > 0:27:17We'll probably make it about a tenth of its normal size.
0:27:17 > 0:27:1910% of what it has at the moment?
0:27:19 > 0:27:22- Wow. That's quite radical, isn't it? - Yes.
0:27:22 > 0:27:24The total volume is going to be about 20ml,
0:27:24 > 0:27:26which is about three or four tablespoons.
0:27:26 > 0:27:29So 90% of the stomach will just be kind of left there, inactive?
0:27:29 > 0:27:30Exactly.
0:27:30 > 0:27:33It's still going to have its blood supply,
0:27:33 > 0:27:35and it's still going to make gastric juices,
0:27:35 > 0:27:37but it will never see food again.
0:27:39 > 0:27:41'And, surprisingly enough,
0:27:41 > 0:27:44'it's not just Bob's stomach they're affecting.'
0:27:44 > 0:27:48Now, you might think that just by reducing the size of the stomach,
0:27:48 > 0:27:51that's how he's going to sort out Bob's problems,
0:27:51 > 0:27:53because a smaller stomach, you eat less...
0:27:53 > 0:27:55it's sort of straightforward.
0:27:55 > 0:28:00But actually, the mechanism by which it works is completely different.
0:28:00 > 0:28:04And it's only relatively recently that they discovered WHY
0:28:04 > 0:28:06doing gastric bypass is so effective.
0:28:06 > 0:28:09The modern thinking actually is that by making a smaller stomach,
0:28:09 > 0:28:13you're actually inducing the changes
0:28:13 > 0:28:15in various chemical messengers,
0:28:15 > 0:28:18which in turn affect hunger levels and fullness levels,
0:28:18 > 0:28:21which in turn cause the weight loss.
0:28:21 > 0:28:23Mmm.
0:28:23 > 0:28:26'So, as well as reducing the size of Bob's stomach,
0:28:26 > 0:28:28'the point of the operation
0:28:28 > 0:28:32'is to change the levels of certain gut hormones.
0:28:32 > 0:28:34'These chemical messengers
0:28:34 > 0:28:37'are released by the gut in response to food,
0:28:37 > 0:28:41'and tell the brain when to eat, or stop eating.
0:28:41 > 0:28:45'One of the hormones, ghrelin, makes you feel hungry.'
0:28:45 > 0:28:47We think that ghrelin is actually being produced
0:28:47 > 0:28:51from this part of the stomach up here. This fundus.
0:28:51 > 0:28:54This is called the fundus of the stomach,
0:28:54 > 0:28:57and this is where all the cells that produce ghrelin are sort of based.
0:28:57 > 0:28:59Now what we think we're doing
0:28:59 > 0:29:01is we're actually separating that part of the stomach completely
0:29:01 > 0:29:03from ever seeing food.
0:29:03 > 0:29:06So the food will never touch those cells that make the ghrelin.
0:29:10 > 0:29:16'Once they're isolated, the ghrelin cells no longer function normally.
0:29:18 > 0:29:22'Hormone production will be reduced, and Bob should feel less hungry.'
0:29:22 > 0:29:25It's extraordinary, isn't it?
0:29:25 > 0:29:28That little area of the stomach can be responsible
0:29:28 > 0:29:30for how hungry you feel?
0:29:32 > 0:29:34The next stage of the operation
0:29:34 > 0:29:41is to re-attach Bob's smaller stomach back to his intestine.
0:29:41 > 0:29:43Good, thanks.
0:29:43 > 0:29:47'From now on, it will be right next to the part of his intestines
0:29:47 > 0:29:51'that produces the gut hormone, PYY, that makes him feel full.'
0:29:51 > 0:29:55How long does food normally take to get there?
0:29:55 > 0:29:58- Uh, probably about 20-30 minutes, I would imagine.- Right.
0:29:58 > 0:30:01So instead of taking, say, 20 minutes for your brain
0:30:01 > 0:30:03to get the message, "You're full, stop eating,"
0:30:03 > 0:30:05- it might take five minutes? - Yeah, about five minutes.
0:30:22 > 0:30:24Mr Ahmed believes the operation
0:30:24 > 0:30:28will have an immediate impact on Bob's appetite.
0:30:28 > 0:30:32Patients who would normally eat three-to-four meals throughout a day
0:30:32 > 0:30:35eat maybe just one or two meals after surgery.
0:30:35 > 0:30:38And when they do eat, they eat really small portions.
0:30:38 > 0:30:40Through side plates, or children's portions,
0:30:40 > 0:30:43because they just don't feel like eating the same amounts
0:30:43 > 0:30:44as they were before.
0:30:44 > 0:30:46And they're happy.
0:30:46 > 0:30:49It's not like something that's imposed on them.
0:30:49 > 0:30:50They actually are very satisfied.
0:30:53 > 0:30:57What I find really astonishing about this operation
0:30:57 > 0:31:00is that the effects are so profound and widespread.
0:31:00 > 0:31:02Because, in essence, what he is doing
0:31:02 > 0:31:05is just sort of making the stomach smaller and connecting the bits,
0:31:05 > 0:31:08and yet, the effect on Bob will be enormous.
0:31:08 > 0:31:12We think that the brain rules our decision-making process,
0:31:12 > 0:31:14but it's pretty clear from this
0:31:14 > 0:31:17that our stomach has a very, very profound effect
0:31:17 > 0:31:19on how we behave.
0:31:30 > 0:31:34Six weeks after surgery, Bob is certainly slimmer than he once was.
0:31:36 > 0:31:40Since the operation, I have lost three stone.
0:31:40 > 0:31:41I was 20 stone.
0:31:41 > 0:31:46Yeah, I've been losing weight, and all my clothes are all loose.
0:31:48 > 0:31:53Crucially, Bob's urge to eat lots of fatty foods has gone.
0:31:53 > 0:31:57I had a bite of a burger. I couldn't swallow it.
0:31:57 > 0:32:00So I'm keeping to my diet.
0:32:00 > 0:32:03I only drink a Cup-a-Soup and I'm full.
0:32:03 > 0:32:05I'm happy with that, and I can stick with that.
0:32:05 > 0:32:07Dad!
0:32:10 > 0:32:14It's just great. The family is happy, I'm happy.
0:32:14 > 0:32:16I can't wait to lose more weight.
0:32:16 > 0:32:18CHILDREN GIGGLE AND SHOUT
0:32:24 > 0:32:29The camera has now been travelling inside me for over four hours.
0:32:29 > 0:32:31It's made its way through
0:32:31 > 0:32:34the acidic and forbidding world of my stomach,
0:32:34 > 0:32:37and embarked on the longest part of its journey.
0:32:37 > 0:32:42The small intestine, or small bowel.
0:32:48 > 0:32:52Over the next few hours, as it travels along this tube,
0:32:52 > 0:32:56my steak and chips will be broken down, absorbed,
0:32:56 > 0:33:00and transformed into the energy needed to run my body.
0:33:00 > 0:33:05As for me, I'm taking it easy.
0:33:05 > 0:33:10Ooh, it's amazing how contented you feel after a nice big meal.
0:33:10 > 0:33:12Also how tired and slothful.
0:33:12 > 0:33:15STOMACH GURGLES
0:33:21 > 0:33:24And I suppose it's no surprise I'm tired.
0:33:24 > 0:33:28There's a frenzy of digestion going on inside me.
0:33:32 > 0:33:36As I snooze, the tight folds on the wall of the small intestine
0:33:36 > 0:33:41and mixing and churning my mushed-up food in a corkscrew motion.
0:33:43 > 0:33:49Digestive enzymes from the pancreas and gall bladder flood the area.
0:33:49 > 0:33:53These enzymes induce chemical reactions,
0:33:53 > 0:33:57which break the food down into nutrients
0:33:57 > 0:33:59that my body can readily absorb.
0:34:02 > 0:34:08The walls of my small intestine look a bit like a fluffy towel.
0:34:11 > 0:34:13And they are there to aid absorption.
0:34:16 > 0:34:19So, on the folds here, on the folds of the small bowel,
0:34:19 > 0:34:22you can see the finger-like projections
0:34:22 > 0:34:24of the small bowel lining, which are called villi.
0:34:24 > 0:34:28What they do is increase the surface area of the small bowel hugely.
0:34:28 > 0:34:30What sort of surface area are we talking about?
0:34:30 > 0:34:33About a tennis-court size, if you strip it all out.
0:34:33 > 0:34:34So it's really huge.
0:34:34 > 0:34:37There is a huge amount of work that goes on in there.
0:34:40 > 0:34:43And all this work requires a healthy blood supply.
0:34:45 > 0:34:48As I'm lying here, digesting my steak and chips,
0:34:48 > 0:34:51a third of my body's blood is being diverted
0:34:51 > 0:34:57away from my extremities and towards the action in my guts.
0:34:57 > 0:34:59There's active noises down there!
0:35:01 > 0:35:05And as this blood rushes through the vessels
0:35:05 > 0:35:07in the wall of my small intestinal,
0:35:07 > 0:35:10it's picking up digested nutrients,
0:35:10 > 0:35:12and transporting them all over my body.
0:35:19 > 0:35:22But this could take another three or four hours.
0:35:22 > 0:35:25So there's time for me to get more hands-on
0:35:25 > 0:35:28with another digestive system.
0:35:33 > 0:35:36- Ooh, yes!- Here we go! - That's a treat, isn't it?!
0:35:36 > 0:35:39'Surgeon and gut specialist James Kinross
0:35:39 > 0:35:42'has brought along the intestine of an animal
0:35:42 > 0:35:45'that was destined for the food chain.'
0:35:45 > 0:35:47So what we have here, this is a pig,
0:35:47 > 0:35:50from mouth down to the anus at this end here.
0:35:50 > 0:35:52Right.
0:35:52 > 0:35:56'Although we don't look much like pigs on the outside,
0:35:56 > 0:35:58'their intestines are remarkably similar to ours.'
0:35:58 > 0:36:00And what you can see is that
0:36:00 > 0:36:03the gastrointestinal tract is basically a tube,
0:36:03 > 0:36:06and it runs from your mouth all the way down to your bottom.
0:36:06 > 0:36:10- OK.- So what you have is the oesophagus at the top end,
0:36:10 > 0:36:13and we can actually trace all of this bowel, the whole way down.
0:36:13 > 0:36:18'The walls of the small intestines feel surprisingly delicate,
0:36:18 > 0:36:22'and they are threaded with tiny capillaries.'
0:36:23 > 0:36:27- What you'll see is there's a layer of connective tissue.- Oh, yes.
0:36:27 > 0:36:30So the bowel has this connective tissue which takes the blood supply.
0:36:30 > 0:36:32And you can see the blood supply here.
0:36:32 > 0:36:35So when you absorb a meal, obviously the nutrition you take out of it
0:36:35 > 0:36:36has to get into the blood supply.
0:36:36 > 0:36:37That's what's happening to me.
0:36:37 > 0:36:40So let's see how long this is.
0:36:40 > 0:36:43'The human small intestine is roughly four metres.
0:36:43 > 0:36:45'The length of this table.
0:36:45 > 0:36:48'A pig's is much longer.'
0:36:48 > 0:36:49Return journey!
0:36:49 > 0:36:52Keep going and keep going.
0:36:52 > 0:36:55'Our intestines absorb about seven litres of food, fluid,
0:36:55 > 0:36:59'and gut secretions every day.'
0:36:59 > 0:37:02- Isn't that majestic?!- Yeah!
0:37:02 > 0:37:06'But perhaps the most extraordinary thing about the intestine
0:37:06 > 0:37:09'is that, buried deep inside its tissue,
0:37:09 > 0:37:11'is a very thin layer of brain.'
0:37:19 > 0:37:21When you think about your brain,
0:37:21 > 0:37:24normally you think about the thing up there in your skull.
0:37:24 > 0:37:27But you actually have a second brain deep down in the gut.
0:37:27 > 0:37:29It's made up of cells like neurons,
0:37:29 > 0:37:31which you also find in your main brain.
0:37:31 > 0:37:34And, in fact, there are over 100 million of them.
0:37:34 > 0:37:39As many as you would find in the brain of a cat.
0:37:43 > 0:37:45The neurons are spread out in a thin mesh
0:37:45 > 0:37:49that extends all the way from the throat to the rectum.
0:37:52 > 0:37:59This brain in our gut orchestrates our digestion.
0:37:59 > 0:38:02It's also involved in gut pain.
0:38:02 > 0:38:04And surprisingly enough,
0:38:04 > 0:38:09the way we respond to pain seems to be linked to our personality type.
0:38:13 > 0:38:16I've got a personality test here which I've got to fill in,
0:38:16 > 0:38:18which could be dangerously revealing.
0:38:18 > 0:38:22It says a number of characteristics here may or may not apply to you.
0:38:22 > 0:38:24I've got to score between one and five
0:38:24 > 0:38:27for each of these particular characteristics,
0:38:27 > 0:38:29where one means disagree strongly,
0:38:29 > 0:38:32and five means agree strongly.
0:38:32 > 0:38:35So, first up - "Is talkative."
0:38:35 > 0:38:38I think...I do like talking.
0:38:38 > 0:38:40I'll give myself a four. Agree a little.
0:38:40 > 0:38:44"Tends to find fault with others." No. Two on that.
0:38:46 > 0:38:49'This test is designed to analyse
0:38:49 > 0:38:53'the broad traits that make up the human personality.'
0:38:53 > 0:38:54"Is original."
0:38:54 > 0:38:56I'm going to give myself a five on that one!
0:38:56 > 0:39:00'Of these traits, two have been strongly linked to the gut.
0:39:00 > 0:39:05'Being extrovert and being neurotic.
0:39:05 > 0:39:09'Extroverts tend to be the life and soul of the party,
0:39:09 > 0:39:13'whereas neurotics are quieter, more anxious,
0:39:13 > 0:39:16'and often put a negative spin on events.'
0:39:16 > 0:39:18Nope. No, I don't like quarrelling.
0:39:18 > 0:39:21"Can be tense." Yes, I can be tense.
0:39:21 > 0:39:22Er...sometimes, sometimes not.
0:39:24 > 0:39:28'Most people are predominantly one or the other.'
0:39:28 > 0:39:31I think I'll give myself a four on that.
0:39:31 > 0:39:33Three. Five. One. Four. Not overly so.
0:39:35 > 0:39:38OK, that's complete. I'm going to send it off for analysis.
0:39:38 > 0:39:41It'll be interesting to see what they make of it.
0:39:46 > 0:39:50My test will be analysed at the Wingate Institute in London,
0:39:50 > 0:39:54by gastroenterologist Dr Adam Farmer.
0:39:54 > 0:39:57So what we're trying to do in this study
0:39:57 > 0:40:01is to relate personality to pain responses
0:40:01 > 0:40:04and to try and link the two together.
0:40:07 > 0:40:11'Adam reckons that my personality
0:40:11 > 0:40:14'will influence the way the neurons in my gut
0:40:14 > 0:40:16'respond to pain he's about to inflict.'
0:40:18 > 0:40:21Just rest your arm there. Just so you're nice and comfortable.
0:40:23 > 0:40:25'These findings are important
0:40:25 > 0:40:29'because they could change the way doctors treat chronic gut pain.
0:40:32 > 0:40:36'The test involves once again, sticking a tube
0:40:36 > 0:40:38'down my nose and into my gullet.'
0:40:38 > 0:40:41So once it's down and sat in your gullet,
0:40:41 > 0:40:43- around about there.- Yeah.
0:40:43 > 0:40:45Then we'll inflate the balloon to cause pain.
0:40:47 > 0:40:49Oh, God!
0:40:50 > 0:40:54OK, here we go. Slight tickling at the back of your nose there.
0:40:54 > 0:40:57'Adam has found that the guts of extroverts and neurotics
0:40:57 > 0:41:00'respond to pain in very different ways.'
0:41:00 > 0:41:03Well done. So the tube's down.
0:41:03 > 0:41:05- You're quite safe now. - HE COUGHS
0:41:05 > 0:41:08'I may be safe, but I fear the worst is yet to come.'
0:41:08 > 0:41:11HE COUGHS
0:41:11 > 0:41:15We're going to give you a series of seven painful stimuli.
0:41:15 > 0:41:19I'm going to inflate the balloon up to your pain-tolerance level.
0:41:19 > 0:41:20And what I mean by that is to the point
0:41:20 > 0:41:22where you can't tolerate any more.
0:41:22 > 0:41:24Where you've had enough.
0:41:24 > 0:41:26- Are you ready? - I'm ready. And you're ready?
0:41:26 > 0:41:29- I'm just about ready.- OK.
0:41:29 > 0:41:30Ooh, yeah!
0:41:31 > 0:41:33OK!
0:41:33 > 0:41:36Unpleasantness is seven to eight,
0:41:36 > 0:41:38and absolute pain, about an eight.
0:41:38 > 0:41:39Uh!
0:41:39 > 0:41:41Bloody horrible!
0:41:41 > 0:41:43'To see how my body responds to pain,
0:41:43 > 0:41:48'Adam monitors my heart rate and blood pressure.
0:41:48 > 0:41:51'I'm expecting them both to rise,
0:41:51 > 0:41:53'because that's what the textbooks say.'
0:41:55 > 0:41:56So the pain's coming now.
0:42:00 > 0:42:03Oow! Yeah!
0:42:03 > 0:42:05I am keen for you to remove this thing now.
0:42:08 > 0:42:10So, the results.
0:42:10 > 0:42:12'If Adam is right,
0:42:12 > 0:42:15'my pain response will be determined
0:42:15 > 0:42:17'by my personality type.'
0:42:17 > 0:42:19Your psychological results
0:42:19 > 0:42:22- were extremely interesting! - HE LAUGHS
0:42:22 > 0:42:25In terms of...what do you feel your personality traits are?
0:42:25 > 0:42:27Because it's often a good suggestion...
0:42:27 > 0:42:29Yeah, I think I'm probably...
0:42:29 > 0:42:31inclined towards the neurotic.
0:42:31 > 0:42:34People when they meet me, they assume I'm more extrovert,
0:42:34 > 0:42:35but actually,
0:42:35 > 0:42:38I suspect I'm a neurotic posing as an extrovert.
0:42:38 > 0:42:39And absolutely!
0:42:39 > 0:42:44They were very much the results from your personality questionnaires.
0:42:44 > 0:42:48That out of a possible 100 on the neuroticism scale,
0:42:48 > 0:42:50- you scored 75.- OK!
0:42:50 > 0:42:54'And as a neurotic, the changes in my heart rate
0:42:54 > 0:42:57'and blood pressure were exactly what Adam expected.'
0:42:57 > 0:43:02So we can see that, in response to the balloon,
0:43:02 > 0:43:04you actually dropped your blood pressure
0:43:04 > 0:43:07and slowed your heart rate down
0:43:07 > 0:43:10for a transient couple of seconds.
0:43:10 > 0:43:13I find that really, really surprising, I must admit.
0:43:13 > 0:43:17Because I would absolutely have expected them to go up.
0:43:17 > 0:43:19I've always been taught pain, basically,
0:43:19 > 0:43:22your heart rate goes up, your blood pressure goes up.
0:43:22 > 0:43:23Your body doesn't like it.
0:43:23 > 0:43:29'It seems, however, that when neurotics are hurt, the vagus nerve,
0:43:29 > 0:43:34'a nerve that connects your brain to your gut, becomes more active.
0:43:34 > 0:43:37'This causes heart rate and blood pressure to drop.
0:43:37 > 0:43:41'Which in turn, is believed to have a calming effect,
0:43:41 > 0:43:44'reducing the amount of pain that's felt.'
0:43:44 > 0:43:46- And you don't find that in extroverts?- No.
0:43:46 > 0:43:49Extroverts tend to have the more classic, heart rate goes up,
0:43:49 > 0:43:51blood pressure goes up.
0:43:51 > 0:43:56'For Adam, the results mean that neurotics and extroverts
0:43:56 > 0:44:00'could be treated for gut pain in very different ways.'
0:44:00 > 0:44:03For instance, those who have high neuroticism scores,
0:44:03 > 0:44:06we would use psychological techniques
0:44:06 > 0:44:08such as cognitive behavioural therapy.
0:44:08 > 0:44:10Whereas the more extrovert ones,
0:44:10 > 0:44:14we may well use pharmaceutical or drug therapy in these patients.
0:44:14 > 0:44:18Brilliant. I have to say, I rarely go in for an experiment in some form
0:44:18 > 0:44:21where I'm genuinely surprised at the end.
0:44:21 > 0:44:24But I was genuinely, genuinely surprised by this one.
0:44:24 > 0:44:27Great! Well, you were an excellent subject and you did extremely well!
0:44:27 > 0:44:28Thank you!
0:44:28 > 0:44:31Ooh, yeah!
0:44:35 > 0:44:38It's been almost nine hours since I swallowed the camera
0:44:38 > 0:44:42and began life as a museum exhibit.
0:44:42 > 0:44:43During that time,
0:44:43 > 0:44:47the camera has travelled over five metres through my guts.
0:44:47 > 0:44:51But from now, things will really slow down,
0:44:51 > 0:44:55and move along at an even more leisurely pace.
0:45:00 > 0:45:03We're at the outer reaches of this alien world.
0:45:03 > 0:45:05The large intestine, or colon.
0:45:09 > 0:45:12You can see that the lining of the colon
0:45:12 > 0:45:16is very much flatter and whiter than the small bowel.
0:45:16 > 0:45:19And you can see the little blood vessels running through
0:45:19 > 0:45:22very, very clearly in the colon.
0:45:22 > 0:45:24Right.
0:45:24 > 0:45:26It's very weird, isn't it?
0:45:29 > 0:45:32It's a big organ, so you can often see a big hole,
0:45:32 > 0:45:36whereas the small bowel is very long, but very small in diameter.
0:45:36 > 0:45:38COLON GURGLES AND RUMBLES
0:45:44 > 0:45:48Through the flatter, wider surfaces of the colon,
0:45:48 > 0:45:53water is being drawn out from what remains of my food.
0:45:53 > 0:45:56We have some slightly more formed material in there.
0:45:56 > 0:45:57HE LAUGHS
0:46:00 > 0:46:02That's Mark's polite way of saying
0:46:02 > 0:46:05that what we're looking at is faeces.
0:46:09 > 0:46:12But it's not just leftover food.
0:46:12 > 0:46:16A third of the weight of my faeces is actually bacteria.
0:46:16 > 0:46:24There are trillions of them, and they form their own mini-ecosystem.
0:46:24 > 0:46:29They feed on the food that my small intestine wasn't able to digest.
0:46:29 > 0:46:33Helpfully breaking it down into nutrients, and also making vitamins.
0:46:33 > 0:46:38From their dark, dank home in the colon,
0:46:38 > 0:46:43these bacteria play a critical role in keeping us healthy.
0:46:55 > 0:46:59Most of us don't want to think too hard about faeces.
0:46:59 > 0:47:02But I'm off to meet a scientist who is absolutely fascinated by it.
0:47:02 > 0:47:05And she claims that you can learn an awful lot about somebody
0:47:05 > 0:47:08simply by examining their excrement.
0:47:08 > 0:47:10Well, I've sent her a sample of my own,
0:47:10 > 0:47:15and I'm off now to discover just what she has learned about me.
0:47:22 > 0:47:28Microbiologist Dr Gemma Walton spends her professional life
0:47:28 > 0:47:33investigating the different bacteria that colonise our guts.
0:47:33 > 0:47:35It's important work,
0:47:35 > 0:47:39but her research does give her laboratory a very distinctive odour.
0:47:41 > 0:47:43Eurgh! God!
0:47:43 > 0:47:46- HE COUGHS - Oh, that is... Hello, Gemma!
0:47:46 > 0:47:49- SHE LAUGHS - Hi, there! Nice to meet you!
0:47:49 > 0:47:51I'm not sure I should shake hands!
0:47:51 > 0:47:54That is...that is a truly revolting smell!
0:47:54 > 0:47:56It's..erm...a lovely lab smell!
0:47:56 > 0:47:58It's not a lab smell!
0:47:58 > 0:48:01It's the worst bathroom, pooey smell!
0:48:02 > 0:48:05'Inside these flasks,
0:48:05 > 0:48:08'Gemma has recreated the conditions found in the human colon.
0:48:08 > 0:48:13'She uses this to study some of the huge variety of bacteria
0:48:13 > 0:48:14'that live there.
0:48:14 > 0:48:18'Each of us has our own unique mix of different strains.
0:48:18 > 0:48:21'And Gemma has been looking at mine.
0:48:21 > 0:48:24'First up, lactobacillus.'
0:48:24 > 0:48:27So, lactobacillus is a big group of bacteria
0:48:27 > 0:48:31associated with some quite beneficial effects.
0:48:31 > 0:48:35'As well as helping break down food, lactobacillus excrete acid
0:48:35 > 0:48:40'which fights off other more harmful bacteria.'
0:48:40 > 0:48:42So these are good guys?
0:48:42 > 0:48:46So, yes. These are your own good guys.
0:48:46 > 0:48:51'But she's also find some species that don't sound so friendly.'
0:48:51 > 0:48:53If you have a look at that plate there for me.
0:48:53 > 0:48:57- Do you see some pink colonies on there?- Yes.
0:48:57 > 0:49:00Now, those pink colonies are likely to be E. coli.
0:49:00 > 0:49:03Right. E. coli, I think of
0:49:03 > 0:49:06as food poisoning, infections of the urinary tract...
0:49:06 > 0:49:09Well, E. coli are often associated with those events.
0:49:09 > 0:49:13However, there are many, many different strains of E. coli.
0:49:13 > 0:49:16So it is not necessarily something negative.
0:49:16 > 0:49:18In fact, I would be more surprised
0:49:18 > 0:49:20if I couldn't find any within your sample.
0:49:20 > 0:49:24- So they're a perfectly normal part of the gut balance.- OK.
0:49:24 > 0:49:29'Gemma reckons I have over 1,000 different strains
0:49:29 > 0:49:32'of bacteria in my faeces.
0:49:32 > 0:49:35'And fortunately, I have a healthy mix.
0:49:35 > 0:49:38'But that balance can become upset,
0:49:38 > 0:49:41'leading to diarrhoea and irritable bowels.
0:49:41 > 0:49:45'If that happens, the good guys may need help.'
0:49:45 > 0:49:48So there's two ways that you can do that.
0:49:48 > 0:49:50It's the prebiotic way,
0:49:50 > 0:49:52so the prebiotic is the food you eat
0:49:52 > 0:49:55that then is a food for your bacteria.
0:49:55 > 0:49:59So that can help increase numbers of your beneficial bacteria.
0:49:59 > 0:50:02The other way you can top up the good bacteria
0:50:02 > 0:50:05is by consuming probiotic products
0:50:05 > 0:50:07that actually have their own live bacteria in.
0:50:07 > 0:50:11And you're introducing them into your gut by consuming them.
0:50:11 > 0:50:15In some cases, that's not enough.
0:50:21 > 0:50:24Another lab, and more faeces.
0:50:24 > 0:50:26This time, St Mark's Hospital in London.
0:50:30 > 0:50:32Gastroenterologist Dr Ailsa Hart
0:50:32 > 0:50:35is working with colleagues from Imperial College
0:50:35 > 0:50:39on novel approaches to rebalancing gut bacteria.
0:50:41 > 0:50:46The most drastic of which involves performing a faecal transplant.
0:50:50 > 0:50:55- Hello, there!- Hello!- Michael. So what's happening in here?
0:50:55 > 0:50:57We're just in the process of preparing a sample
0:50:57 > 0:51:01for a faecal transplant that we're doing as part of a research trial.
0:51:01 > 0:51:05'In this pilot study, faeces from a healthy donor
0:51:05 > 0:51:07'are transplanted into the guts of patients
0:51:07 > 0:51:12'suffering from a condition called pouchitis.'
0:51:12 > 0:51:16Pouchitis is a form of inflammatory bowel disease,
0:51:16 > 0:51:19and normally that's treated very simply with antibiotics,
0:51:19 > 0:51:23but in a small group of patients, when the antibiotics haven't worked,
0:51:23 > 0:51:26the next line of therapy becomes a little bit trickier.
0:51:26 > 0:51:29And it's in that group that we're going to try this technique.
0:51:33 > 0:51:37They are hoping to replace the unhealthy mix of bacteria
0:51:37 > 0:51:40in the patient's guts with a healthy mix of someone else's.
0:51:42 > 0:51:46First, the donor faeces are blended with salt water...
0:51:49 > 0:51:50..and then filtered.
0:51:53 > 0:51:56It sounds, I must admit, slightly revolting!
0:51:56 > 0:51:59It does sound revolting! It sounds disgusting!
0:51:59 > 0:52:01But this is for a group of patients
0:52:01 > 0:52:04who have had a lot of therapies beforehand,
0:52:04 > 0:52:06troubled by lots of diarrhoea, awful incontinence,
0:52:06 > 0:52:09and really dreadful quality of life, actually.
0:52:09 > 0:52:15The next stage is to put the faecal solution into the patient.
0:52:15 > 0:52:17We take a nasogastric tube.
0:52:17 > 0:52:20- Down the nose, presumably?- Down the nose, into the patient's stomach.
0:52:20 > 0:52:22And then it's simply the syringe goes on to there
0:52:22 > 0:52:24and you put it into the patient's stomach.
0:52:24 > 0:52:27- And it just goes straight in? - Straight to the stomach.
0:52:30 > 0:52:33Dr Hart is looking for signs that this radical approach
0:52:33 > 0:52:38will improve her patients' symptoms.
0:52:38 > 0:52:41So by giving this transplant, are we able to alter the bacteria
0:52:41 > 0:52:43in the guts of these patients,
0:52:43 > 0:52:45and is it having a clinical benefit in them as well?
0:52:47 > 0:52:49It's early days, and so far,
0:52:49 > 0:52:54only a handful of patients have taken part in the study.
0:52:54 > 0:52:57It's the most densely-populated ecosystem on the Earth.
0:52:57 > 0:53:00So to try and understand it is a very tall order.
0:53:00 > 0:53:03To try and modulate it...you know, you do ask the question,
0:53:03 > 0:53:05- "Are we, as human beings, clever enough to do this?"- Mmm.
0:53:11 > 0:53:17Back at the Science Museum, my food has been digested and absorbed.
0:53:17 > 0:53:21What's left has been chewed over by my gut bacteria
0:53:21 > 0:53:26and is now nearing the end of its journey.
0:53:26 > 0:53:29But faeces are not the only thing
0:53:29 > 0:53:32that the bacteria in your gut produce.
0:53:32 > 0:53:35Flatulence. All of us produce gas.
0:53:35 > 0:53:39I guess the question is, how much do we produce? Any guesses?
0:53:39 > 0:53:42I would say about seven times a day.
0:53:42 > 0:53:44Ooh, about 12 to 15.
0:53:44 > 0:53:46100 times?
0:53:46 > 0:53:4725-30.
0:53:47 > 0:53:50I always thought it was 13.
0:53:50 > 0:53:52I haven't farted so far today! THEY GIGGLE
0:53:52 > 0:53:55- You farted on the way here, in the coach!- No, I didn't!
0:53:55 > 0:53:57- A few hundred.- 20 or 30.
0:53:57 > 0:53:58Five?
0:53:58 > 0:54:00- Five times a day?!- Yep. - No, it's a lot more.
0:54:00 > 0:54:025,000.
0:54:02 > 0:54:05There could be ones that you don't even notice. You know, involuntary.
0:54:10 > 0:54:14'In fact, we're letting out an average of 12 to 15 every day.
0:54:14 > 0:54:18'Typically releasing about two litres of gas.'
0:54:18 > 0:54:22I was looking to see what he had going on!
0:54:22 > 0:54:25'Fortunately, according to Gemma, not all of them are smelly.'
0:54:25 > 0:54:28Well, there's two types of flatulence.
0:54:28 > 0:54:32Some people have very odorous flatulence and some people less so.
0:54:32 > 0:54:34HE GIGGLES
0:54:34 > 0:54:37'If you have particularly unpleasant flatulence,
0:54:37 > 0:54:40'blame the mix of bacteria in your colon.'
0:54:43 > 0:54:46'Some produce pungent hydrogen sulphide gas,
0:54:46 > 0:54:50'others the less odorous but more flammable methane.
0:54:50 > 0:54:54'And just as diet can affect the balance of good and bad bacteria,
0:54:54 > 0:54:58'so it can alter the balance of sulphur to methane producers.'
0:54:58 > 0:54:59By changing your diet,
0:54:59 > 0:55:02you might actually increase the amount
0:55:02 > 0:55:03of hydrogen sulphide produced.
0:55:03 > 0:55:06If you're eating quite a sulphate-rich diet.
0:55:06 > 0:55:11Which are the foods that actually produce the worst flatus?
0:55:11 > 0:55:14It would be things like beer and wine,
0:55:14 > 0:55:17breads, vegetables.
0:55:17 > 0:55:19Vegetables? This is a reason not to eat vegetables!
0:55:19 > 0:55:21No, not at all!
0:55:21 > 0:55:24Flatus is actually a really, really healthy side effect
0:55:24 > 0:55:25of eating fibre in the diet.
0:55:25 > 0:55:28So it's something you really want to be doing!
0:55:28 > 0:55:29HE GIGGLES
0:55:35 > 0:55:40Right, I thought I'd share with you, this is the essence, if you like, of really horrible flatulence.
0:55:43 > 0:55:44It's a sulphide group,
0:55:44 > 0:55:47and I thought that you would be keen to have a little smell.
0:55:47 > 0:55:49- CROWD GROANS - No, thanks!- It's fine!
0:55:49 > 0:55:51What do you think?
0:55:51 > 0:55:54- HE LAUGHS - Does anyone recognise the smell?
0:55:54 > 0:55:56These are sulphides.
0:55:56 > 0:55:57No? Not for you?
0:55:57 > 0:56:00HE COUGHS AND SPLUTTERS
0:56:00 > 0:56:03That's really, really revolting, isn't it?
0:56:07 > 0:56:12Maybe it was the smell that put them off.
0:56:12 > 0:56:17But it's late, and the Science Museum is about to close.
0:56:17 > 0:56:20The day has certainly been eventful.
0:56:20 > 0:56:25And this alien world in my guts is a bit more familiar now.
0:56:25 > 0:56:28There's still quite a lot of gunge around there, isn't there?
0:56:28 > 0:56:33'Time for one more peek at what's going on inside me.
0:56:33 > 0:56:36'And there's one last question on my mind.
0:56:38 > 0:56:40'When's the camera going to come out?
0:56:42 > 0:56:45'I know it will work its way out of my system,
0:56:45 > 0:56:50'and that could happen sooner rather than later.'
0:56:50 > 0:56:53I think I need to go urgently to the loo! I will be back!
0:56:53 > 0:56:55I'll see you shortly.
0:56:58 > 0:57:00That's good.
0:57:00 > 0:57:02It might come out yet!
0:57:08 > 0:57:10Urgh!
0:57:11 > 0:57:12Mmm!
0:57:13 > 0:57:16Mmm!
0:57:16 > 0:57:19'Over the last 12 hours, as I've digested my food,
0:57:19 > 0:57:22'my guts have been under intense scrutiny.
0:57:25 > 0:57:29'They've been poked and prodded in more ways
0:57:29 > 0:57:31'than I could have possibly imagined.'
0:57:31 > 0:57:32Brings tears to your eyes!
0:57:32 > 0:57:33Oww!
0:57:36 > 0:57:39'Along the way, I've discovered
0:57:39 > 0:57:43'that what goes on inside this mess of tubing
0:57:43 > 0:57:47'not only profoundly affects our health and wellbeing,
0:57:47 > 0:57:49'but our behaviour too.
0:57:57 > 0:58:00'My experience as a museum exhibit
0:58:00 > 0:58:05'has left me with a huge respect for my gut and its inhabitants.
0:58:05 > 0:58:08'They are working together
0:58:08 > 0:58:10'with an intelligence and complexity
0:58:10 > 0:58:12'that we're only just beginning to understand.
0:58:17 > 0:58:20'And as for the camera,
0:58:20 > 0:58:24'it did eventually find its way out.
0:58:24 > 0:58:28'But that's one part of this process that I'm going to keep private.'
0:58:51 > 0:58:55Subtitles by Red Bee Media Ltd