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.

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.

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.

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.

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 !