Good Bacteria (Probiotics), Bioremediation, and Life on Titan
On this show we are joined by microbiologist and probiotic expert Professor Glenn Gibson, from the University of Reading, to talk about friendly bacteria and how they can affect human health, and bioremediation researcher Professor Lynne Macaskie, from the University of Birmingham, who explains how bacteria can be used to help clean up the environment by eating concrete and oil spills. Also joining us are pathologist Professor John Lee, who discusses his new TV programme "Anatomy for Beginners" featuring human dissection, and space scientist Professor John Zarnecki who brings us up to speed with the success of the Huygens mission to Titan, Saturns largest moon.
In this episode
New Highly Efficient, Wearable, Solar Cell Material
Scientists from the University of Toronto have invented a flexible solar cell material that is five times more efficient than current methods of turning the sun's energy into electricity. Unlike existing solar cell technology, which uses visible light and is capable of turning at best 6% of the sun's energy into useable electrical energy, the new material engineered by Ted Sargent and his team harnesses infrared light and can capture 30% of the sun's power to produce electricity. Their reliance on infrared means that the new cell can produce electricity even on a cloudy day or in the dark because although visible light may be lacking, things that are warm, including people and animals, are emitting infrared radiation which the cell can use. An added bonus is that the new material is also highly flexible so it can be turned into a film to coat the surfaces of cloth, paper or other materials, potentially paving the way for wearable solar garments which Sargent terms "portable electricity". This means that you could run your electronic gadgetry off your coat, or have a roll-up solar cell to help recharge your laptop, on the move. Sargent is now looking for investors to help commercialise the invention which, he says, could be on the market within 5 to 10 years
- Anatomy For Beginners
Anatomy For Beginners
with Prof. John Lee John - The programme I'm presenting is called Anatomy for Beginners. The aim of the programme is to make anatomy accessible to anyone who's interested. We've tried to do a genuine demonstration of anatomy
The show starts on Monday night but is being broadcast quite late as this type of programme has never been shown before. Being late in the schedule will also reduce the number of people turning on by accident and not liking it - only people who want to watch it will stay up until 11.05pm. The content is quite strange and some people might find it gruesome. However, we have made the programme in a very straightforward way, not violent and upsetting like many action films. Anybody interested in biology and curious about their own body will like it.
Kat - What's your favourite part of the body?
John - Definitely the brain. All animals have muscles, eyes and so on, but nothing is quite as complex as the human brain. I think it is probably one of the most complex things in the universe.
Chris - Many medical schools are stopping dissection. What do you think about this?
The situation shocks me. Trainee doctors hardly do any dissection for themselves nowadays and instead look at prepared dissections. At some medical schools the students only use plastic models and books. This means that by watching the dissection programme, the general public wills see more of the human body than some doctors!! Wet practicals (when doctors and scientists look at and examine real organisms and chemicals) make the difference between being able to do something in theory and knowing how to do it in practice.
- Huygens Lands on Titan, Saturn's Largest Moon
Huygens Lands on Titan, Saturn's Largest Moon
with Prof. John Zarnecki Chris - How does it feel to have reached Titan?
John - I got back from Germany yesterday and my feet haven't quite touched the ground yet! I've worked on this project from the beginning, and back then all this was a faraway dream. It's a fantastic achievement!
Chris - What did Huygens see?
John - There are about 100 images of the surface but it's still early days in interpretation. It's clear that there are processes going on there that we're quite familiar with on Earth, including dried up river and lake beds, mountains and shorelines. It's minus 180 degrees on Titan, which means that it's far too cold for water. We think that liquid methane plays the same role that water plays for us, so there are similarities and differences between Earth and Titan.
Chris - Do you think that there's any chance of life on Titan?
John - I would think absolutely not as it's much too cold. The chemistry of the atmosphere has the potential to give rise to life but only if it can make more complex hydrocarbons. This will be the focus of much of the Titan data analysis. We're trying to work out what's on the surface, which seems like a gooey gungy stuff that collects in rivers.
Chris - Now you've looked at Titan, where do you want to explore next?
John - I want to go back to Titan! In fact, studies have already started. The next objective is to have mobility on Titan. So far we've only seen one spot and we'd like to see what the rest of it is like. The ideal thing would be a balloon as we could identify interesting places and decide where to land next. I would also like to go to Europa, one of Jupiter's moons. Lots of data was collected by the Galileo space probe and looks like it has an ocean just below the surface. However, I think my blood pressure might mean the next work should be left to my younger colleagues!
- Bioremediation - using bacteria to clean up our mess
Bioremediation - using bacteria to clean up our mess
with Lynne Macaskie, Birmingham University
Lynne - In Birmingham we are working on bacteria that can eat up the mess and waste we humans make. Bacteria can not only make energy, but they can curb some of the problems of global warming, clean up the environment, eat concrete and mop up oil spills.
Chris - How exactly can we use bacteria to clean up the world?
Lynne - Bacteria have been around for a long time and have changed to suit many different environments. If we feed them something awful, they can adapt quite quickly and start eating it. There is strong pressure on the bacteria to evolve so they can eat the substance, because if they don't, they die. When new microbes are discovered, we take them back to the lab and feed it what we're interested in (such as toxic metals). The bacteria will hopefully become resistant to the metal, grow to superbug proportions, and then eat up the lot!
Chris - Could using bacteria in this way harm the environment?
Lynne - No not really. If the food they are used to eating runs out, the bacteria will just sit and let something else take over.
Kat - You say that people discover new microbes. What kind of bugs do we find in the deep ocean?
Lynne - Lots of very strange ones! The deep ocean is fascinating: almost like another planet. As they are so far away from everything else on earth, they evolve all on their own into many weird and wonderful types. Samples that come up from deep sea cores have lots of new bacteria for us to test and hopefully use to clean up the environment. Some friendly bacteria can be used for eating oil. However, oil does not provide all the essential parts of a bacteria's diet. We therefore have to add in the extra things they are short of. This includes ammonium and phosphate, just like the fertilisers we put on our gardens. So fertilising your bacteria ensures they thrive and clean up mess.
Chris - What will we use for fuel when oil runs out?
Lynne - Bacteria can be used to protect the environment by helping us to move away from using hydrocarbons as fuel. Bacteria can manufacture hydrogen from simple things we no longer want, like chocolate waste or bits of bread! Hydrogen is a very clean fuel as it only gives off water when it is burned. This is a promising avenue for future fuel use.
- The Science of Probiotics
The Science of Probiotics
with Glenn Gibson, University of Reading
Glenn Gibson explains to Chris Smith how probiotics can be beneficial to intestinal health...
Glenn - I work on bacteria in the gut and look at what they do for our diet, why they are there and how they can affect our health.
Chris - Why do you want to build an artificial gut?
Glenn - We've made about 25 artificial guts so far! They cover lots of different age ranges and a range of different gut diseases. We use these to test the effect of diet on the bacteria that grow in them. Diet can stimulate the growth of both beneficial and harmful bacteria. The benefit of building an artificial gut is that it avoids the expensive and long term studies on human volunteers, and is of course an alternative to animal testing.
The gut itself contains a huge number of bacteria; enough to weigh about 1kg! These huge numbers can be reached because the gut is a very favourable environment for bacterial growth. Bacteria reproduce about million times faster than us. Human babies are born sterile, that is, they have no bacteria on or in them. Bacteria are first given to us during the birth process, such as from mum or from the hand of the midwife. Babies born by Caesarean section have slightly different micro-organisms to babies born in the normal manner, but this is not the most important factor to picking up important bacteria. The key issue is whether you are breast or bottle fed.
Chris - What makes a bacterium friendly or hostile?
Glenn - Lactobacillus is friendly and is anaerobic, meaning it doesn't use oxygen. A less friendly bacterium would produce toxins and might have effects in other parts of the body.
Chris - Why should you notice a difference when you drink a probiotic drink?
Glenn - You are drinking millions of micro-organisms but whether they survive your stomach acid is a big point of debate. You should possibly notice a difference if it can get through to your large intestine, but about half the products don't. Only the more robust strains of micro-organisms make it. The other way to increase the amount of bacteria in your gut is to grow more of what you already have. This is known as pre-biotics. Extracts of chicory, onion and garlic can have a positive pre-biotic effect.
Kat - At home I have a hand soap that claims it can tell the difference between good and bad bacteria. Is it rubbish?
Glenn - It might have some mild disinfectant against a certain bad bacteria, but there are many types of bacteria on your hand, so it is unlikely it can accurately tell which is which.
- Can you still get brain damage even if your mobile phone is switched off ?
Can you still get brain damage even if your mobile phone is switched off ?
Mobile phones emit microwaves, but only when they are switched on. This means it's ok to sleep with your mobile. Recently, there have been many people saying that phones are very dangerous. However, you have to keep these things in perspective: smoking is much more likely to increase your risk of cancer than using mobile phones. However, we haven't been using phones for more than 10 years, so there may be a lag period before people notice bad effects. We aren't in the position to say that phones don't cause cancer yet. That said, one group of researchers found that holding an active mobile phone against the head improved the short term memories of male, but not female, student volunteers. Although the effect was small, the researchers pointed out that seeing any effect might mean that long term exposure to microwaves from mobile phones could be bad for the brain.
Are probiotics worth taking ?
They don't do any harm, but they might not do you any good either. That seems quite pessimistic, but it's not a black and white situation. There are about 80 scientific publications showing positive results over a range of ages. Probiotics seem to work better in older people than younger people.
- I tried probiotics for two weeks and now I've got the trots - what's happening! ?
I tried probiotics for two weeks and now I've got the trots - what's happening! ?
It might be the phenylanaline contained in the drink, which can loosen the bowels. Another explanation is that you might be taking a little bit too much. Your body can take a while to adapt as the bacteria in the drink take up residence in the intestine, but these effects shouldn't last long.
- Can cider, vinegar and honey relieve IBS symptoms?
Can cider, vinegar and honey relieve IBS symptoms?
IBS sufferers can have varying problems. I think there is a lot of mileage in probiotics for easing these conditions. Many people say it is purely stress, but I don't agree. It is true that stress can make the gut misbehave, but an unwell gut can make you stressed, so they are intimately connected. In our lab we want to see how we can use diet to reset the gut flora and ha included work on the yeast Candida. IBS is serious and people do need help. Cider and vinegar will be absorbed in the upper gut and so don't get through to where it is needed in the large intestine. However, some things in honey are resistant to digestion and can get through. This can change gut flow. Therefore, honey may be of help.
Is it safe to swallow chewing gum ?
Chewing gum used to be from a rubber plant, but is now artificial. It sticks to the road because it contains long oily polymer chains which are chemically similar to some of the constituents of the road surface. It's very hard wearing stuff and doesn't get digested when you swallow it. It can cling onto the sides of your intestines and distort the gut, are occasionally trigger a dangerous disorder called intussusception where the gut telescopes inside itself, although this is rare in adults. It would be better for the environment if people could swallow it. Until then, it would be good to develop a family of chewing gum-consuming bacteria that could eat it off the pavement !