Excess hygiene may weaken developing immune systems

The hygiene hypothesis states that the cleaner your childhood is, the more vulnerable your immune system will be. Or, to put it more scientifically, that the lack of early exposure to bacteria increases vulnerability to auto-immune diseases. New research carried out on mice confirms that those who had been exposed to a normal environment had significantly healthier immune systems than those who had lived in a very clean environment.

Researchers found that the mice raised in a germ-free environment had inflammation of the lungs and colon, resembling asthma and ulcerative colitis in humans, which was caused by hyperactivity of an invariant natural killer T cell.

They found that lack of exposure in early life could not be compensated for in adult life, but that, caught early enough, germ-free mice exposed to normal microbes in the first few weeks of life can have their immune systems restored to normal.

Source: Science Magazine

First published in March 2012

 

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