The researchers genetically engineered the immune system of lab mice in such a way that they lacked a key protein necessary to respond to the bacteria. The mice were raised in germ-free environments. Some 80% developed severe type 1 diabetes.
When the researchers gave the mice a cocktail, which infused mammalian gut bacteria into their systems, jut 30 percent of the mice became ill.
The study shows even harmless bacteria may be useful in preventing diabetes.