Why do rural children have fewer allergies than townies? The answer lies in the cowshed.
The mystery of why farm children have far fewer allergies may have been solved. For years scientists have speculated that something in the rural environment protects against allergies such as hay fever, asthma and eczema, with some research showing the risk is half that of someone living in a city. But exactly what is responsible for such an effect has not been tracked down.
Now scientists have discovered that the answer lies in the cowshed and, in particular, in two strains of bacteria, Acinetobacter lwoffiiand Lactococcus lactis. When they made the bacteria into nose drops and gave them to laboratory animals, they were immediately protected from allergies. Now the aim is to develop a human version of the drops, which could be the first preventive treatment for the growing problem of allergies. “This is the first research to suggest that the use of cowshed bacteria can protect against allergy,” says Professor Otto Holst, one of the international team who made the breakthrough, which was published in the Journal of Allergy and Clinical Immunology.
There has been an increase in allergies, asthma, hay fever and some forms of eczema in the past two to three decades. It has been estimated that 5.1 million people – one adult in 13 and one child in eight – are being treated for asthma and that 18 million people may develop an allergy at some point in their lives. Allergic reactions are caused by the immune system becoming hyper-sensitive to everyday things such as pollen, dust and to certain foods.
A number of theories have been put forward to explain the rise: for example, a health immune system needs to be exposed in early life to bacteria, infections and other potential problems. If this doesn’t happen, later exposure may result in allergies, especially where there is genetic predisposition. In effect, exposure to bacteria and infections helps to calibrate naive immune systems. The new research comes in the wake of more than 20 studies all of which have indicated that children brought up on farms have low levels of allergy, hay fever and asthma. But while they established a link, they did not track down what was responsible.
Source - Times