Through the cakehole! Film-maker becomes a living exhibit at the Science Museum taking spectators on a journey into the dark, dank, private world of his intestines

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UPDATED:

21:21 GMT, 30 June 2012

If I’d known what it involved, I would have thought longer before agreeing. But how often do you get a chance to become a living exhibit at the Science Museum in London Or watch a journey through your insides in front of hundreds of enthusiastic spectators

So when the BBC asked me to swallow a camera as part of a series about the mysteries of the human body, I signed up.

The world of our guts is normally a dark, dank, private one. Down there live creatures that have never seen the light of day – more than 50 trillion of them – and which impact on our health in ways we are only just beginning to understand.

In preparation for the big day, I fasted for 24 hours and drank four litres of a vile-tasting laxative. It sounds an awful lot to drink (and it was), but apparently it is essential to have a complete clearout as otherwise the camera would be sending back nothing but murky pictures.

Open wide: Michael Mosley with the camera pill which will turn him into a living exhibit at the Science Museum

Open wide: Michael Mosley with the camera pill which will turn him into a living exhibit at the Science Museum

The next morning, I met my guide at the Science Museum, gastroenterologist Dr Mark McAlindon, one of the UK’s leading pill camera experts. He normally uses these cameras to help diagnose gut disorders; pill cameras can go places that flexible endoscopes struggle to reach.

During my medical training – and as a presenter of BBC science documentaries such as The Truth About Exercise, my investigation of the benefits of three minutes of exercise a week – I have taken part in painful and unusual experiments. But nothing quite like this.

The camera I had to swallow was a little more than a centimetre long, the size of a large vitamin pill. Considering it houses the equivalent of a film crew, complete with lights, it is impressively small, although still a bit of a gulp.

It takes three pictures a second and transmits them to a receiver, or in my case to giant screens in the Science Museum, via the sensors on my body.

My first feelings after swallowing the camera were of relief; I had actually managed to get it down, though there was an awkward moment when it seemed to get stuck at the bottom of my oesophagus, the tube that leads into the stomach. I jumped up and down to the amusement of the crowd and it was soon through.

The images it sent back when it reached my stomach were of a cavernous, alien landscape, throbbing with movement. When it’s empty, the mucosa that lines the stomach is thrown up in folds like a boggy marsh. It reminded me of the surface of Mars. Except slimier.

Experiment: Michael Mosley with Dr McAlindon at the Science Museum

Experiment: Michael Mosley with Dr McAlindon at the Science Museum

The walls of the stomach are constantly on the move, contracting and folding in on themselves. If the camera had been digestible it would have been pounded and mashed into fragments, then dunked in gastric juices as acidic as a car battery. Instead, it escaped my stomach unscathed and passed into the small intestine.

The small intestine surface is covered in folds with fine, hair-like projections called villi designed to maximise the surface area available for digestion, increasing it to about the size of a tennis court.

Every few seconds, the surface convulses as a muscular wave passes by, mixing and churning the small packages of food that the stomach delivers to the intestine. It’s vital these waves are well co-ordinated, otherwise there would be serious blockages further down.

We each house a thousand or so
different strains of bacteria in our guts, a mix which varies from
person to person

Fortunately, you have a second brain
in your gut orchestrating everything. Just like your main brain, this
one is made up of cells called neurons.

There are more than 100 million
of them spread in a fine mesh throughout the intestine and only really
visible under the microscope.

Nine hours after I swallowed it, my
camera had travelled just five metres, finally reaching the large
intestine or colon. The lining of the colon is much flatter and whiter
than the small intestine and I could see little blood vessels running
though the walls.

Here, the camera encountered the first signs of alien life: microbes. The microbes that live there are mainly bacteria, but there are also some fungi and simple, primitive animals called protozoa. Together they form their own complicated eco-system, living on food that your body can’t absorb.

Although there are trillions of them, I couldn’t actually pick them out but we did begin to encounter small murky fragments of what Mark called ‘formed matter’ (faeces). At least 35 per cent of faeces is made up of bacteria.

Journey into the unknown: An endoscopic view of a healthy sigmoid colon

Journey into the unknown: An endoscopic view of a healthy sigmoid colon

We each house a thousand or so different strains of bacteria in our guts, a mix which varies from person to person and which we get mainly from our mothers.

Although the mix of bacteria in our guts is largely inherited, it can be affected by what we eat.

Research at the University of Chicago, for example, suggests that a diet rich in saturated milk fats, the sort found in many processed foods, causes a species of bacterium called Bilophila wadsworthia to thrive, and they may be behind the increasing numbers of people developing painful inflammatory bowel conditions such as Crohn’s and ulcerative colitis.

Higher levels of ‘bad’ bacteria are also found in the guts of young children who later develop allergies, while people who are obese tend to have a different mix of bacteria to their leaner friends.

This new knowledge opens the way to fresh approaches when it comes to dealing with gut disorders. If we can alter the microbial balance in the guts of a sufferer, perhaps we can treat their symptoms.

One approach being tried is to encourage more ‘good’ bacteria to grow in the guts, either by parachuting new ones in (probiotics) or encouraging the ones there to grow by feeding them the foods they like (prebiotics).

You can already buy probiotics in the form of ‘live’ yogurts, and prebiotics (foods such as garlic, leeks and Jerusalem artichokes) seem to encourage ‘good’ bacteria.

After putting on a spectacular 14-hour show, the pill camera decided to hang around the rather boring world of my colon, so we bid the Science Museum a fond farewell.

As for the camera, well it eventually worked its way out. Or at least I think it has. I haven’t been checking.

Guts: The Strange And Mysterious World Of The Human Stomach will be screened on BBC4 at 9pm on Tuesday, July 10.