Diabetes link to hygiene
Clean environments could be linked to a rise in the number of under-fives with diabetes, according to a new study.
Scientists from the University of Bristol, reporting online in the journal Nature, carried out experiments on genetically modified mice that lacked the part of their immune system that responds to bacteria. They found that 80 per cent of mice raised in a completely germ-free environment and lacking 'friendly' bacteria developed diabetes.
Research last year by other Bristol University researchers found there had been a five-fold increase in the incidence of Type 1 diabetes in children aged under five in the past 20 years.
The latest findings support the 'hygiene hypothesis' - the theory that a lack of exposure to bacteria in the developed world may be leading to a higher risk of developing asthma, allergies and other disorders of the immune system.
Researcher professor Susan Wong told Nursery World that as the experiment was carried out in mice, the results could not at the moment relate directly to humans, but the findings may suggest why the number of young children with Type 1 diabetes is increasing.
She said, 'Exposure to bacteria conditions our immune system in how we react. When "friendly" bacteria were introduced in the mice, they got less diabetes. These bacteria help to train the immune system not to attack itself.'
She added, 'Type 1 Diabetes has appeared to increase in young children. What's important for us to study further is which particular bacteria are important, when these influences are important in life, and relate this to human diabetes.
'We'd like to look at patterns of gut bacteria in humans, how these bacteria condition the immune response and prevent disease.'
According to Diabetes UK, there are 20,000 children under 15 with Type 1 diabetes. Dr Ian Frame, the charity's director of research, said, 'We have known for some time about the association between early infection and 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.'
He added, 'We wouldn't advise people giving large quantities of probiotic foods to children at risk of developing Type 1 diabetes on the basis of these results.'
