Scientists say, Being too clean could increase the risk of diabetes. They say a lack of exposure to bacteria and viruses during childhood may explain why the number of under-fives with type one diabetes has soared in recent years.
The number of cases is now five times the level it was in the mid-1980s.
The University of Bristol study, which is published online in the journal Nature, also found that so-called ‘friendly’ bacteria in the gut can prevent the onset of this form of diabetes.
The findings support a ‘hygiene hypothesis’ theory that a lack of exposure to bacteria and viruses may actually lead to an increased risk of diseases like allergies, asthma, and other disorders of the immune system.
Exposure to some forms of bacteria might help to prevent the onset of type 1 diabetes, which often develops in childhood, where the immune system launches an attack on cells that produce insulin.
The study used genetically modified mice that lacked the part of the immune system that responded to bacteria.
They found that 80 per cent of the mice raised in a completely germ-free environment, and therefore lacking ‘friendly’ gut bacteria, developed severe diabetes.
But when they gave mice a cocktail of the usual bacteria found in the gut the incidence of diabetes fell dramatically.
Professor Susan Wong, from Bristol University, who worked with scientists from Washington University, The Jackson Laboratory and UCLA, said: “Understanding the relationship between our gut “flora” and our immune system is extremely important. The objective now is to identify which friendly bacteria are having this effect, and how they stop the development of type 1 diabetes.”
The study does not relate to type 2 diabetes, the much more common form of the disease which is linked to obesity and lifestyle, that affects almost two million people in Britain.
Dr. Iain Frame, director of research at Diabetes UK, warned that although the research was interesting, the charity would urge against people feeding large amounts of pro-biotic foods to children.
“We have known for some time about the association between early infection and the development of type 1 diabetes,” he said.
“The results presented here also suggest that some infections may help to protect against the development of type 1 diabetes. As always with experiments involving animal models, the trick for the researchers will be to prove their hypothesis in humans. The difficulty will be dissecting what factors are the triggers and we are a long way from finding that out. We wouldn’t advocate people giving large quantities of pro-biotic foods to children at risk of developing type 1 diabetes on the basis of these research results.”
Source: The News, Thursday, September 25, 2008