In an opinion piece published by BBC News, food safety expert, Professor Hugh Pennington, writes:

Some say we have taken hygiene in the home far too far, and that is why conditions like asthma are so common.

Our immune system has become so starved of microbes to attack that it turns in on us because we are excessively clean.

Others say that microbial dangers lurk in our homes, that our toilets are battlegrounds, and that bacteria thrive in our kitchens.

Smelling Nice

What are the facts? There is no doubt that asthma has become more common.

But it is not a new disease. It occurred when most people had only one bath a week - if they were lucky.

And in spite of our current obsessive endeavours to smell nice, the number of bacteria on our skin and hair and up our noses and in our bowels is no less than it ever was.

Even the bacteria that we fight the hardest, like MRSA (a nose specialist) and C. difficile (a gut specialist), have shown themselves to be cunning enemies. We may be beginning to win the war with them, but victory is a long way off.

My scepticism about the proposition that our homes are too safe is driven by Campylobacter ('Campy').

It is the leading bacterial cause of food poisoning but it hardly ever hits the headlines because journalists can't spell it and because it does not cause dramatic outbreaks like Salmonella or E.coli O:157.

But it is far more common than both of them put together. In Britain, there are about 360,000 cases every year.

It is a safe bet that many of them start in the home and that it is practices in the kitchen that give Campy a flying start.

Manure to Mouth

For the poultry industry it is an embarrassing fact that Campy is a natural bug of birds. It lives in their bowels. Raw chicken is sometimes covered with thousands of them - and a hundred or so can cause gastroenteritis.

So anyone who does not wash their hands after handling poultry meat and does not disinfect the chopping board before preparing the salad is likely to add themselves or members of their family to the diarrhoea statistics.

To be fair to the industry, they have been trying hard to keep Campy out of their flocks.

But it is turning out to be an uphill struggle.

Free-range and organic birds are just as likely to have it, and some of them have been shown to have more: seagulls flying overhead are dropping it on them!

So the kitchen has the potential to be most dangerous room in the house.

Making it safe is easy. When handling raw meat mutter the mantra 'turd to tongue' or - if you have squeamish tendencies - 'manure to mouth.

After the meat has touched your hands, or a work surface, there is a real probability that this natural product will be on them.

Washing the first, and disinfecting the second, or best of all, having one for raw only, makes things safe.

As for washing up bowls, they are anathema. From the microbiological point of view, at the end of a session with one, the dishes are being washed in a microbial soup.

Ask anyone about what domestic benefits space travel have brought. It is likely that they will say 'teflon'. Wrong. Teflon was discovered in 1938.

But NASA did develop a brilliant system to deliver safe food - because the notion of diarrhoea and vomiting in zero gravity was too awful to contemplate. It is called HACCP - hazard analysis and critical control points.

It puts in writing what anyone with a bit of common sense and basic biology can work out for themselves; that cooking and disinfection and dishwashers spell Campy death and that hand-washing sends it down the drain.

Join the astronauts. They were never sick in space.

But our food poisoning figures say that we still have a long distance to travel.