Researchers looking for the cause of type 2 diabetes—the one that afflicts 90% of diabetics—generally focus on what people put into their stomachs. Too much food and too many unhealthy carbohydrates are some of the root causes of the disease.
Now researchers looking into the cause of type 1 diabetes are focusing on what people haven’t put into their gut.
In type 1 diabetes, the body’s own immune system attacks the pancreas, causing it to either produce too little insulin or none at all. But no one really knows why the immune system does this; theories range from viruses to genetics.
A new study in mice, however, points to another possible cause: not enough exposure to germs.
Scientists from Yale University and the University of Chicago studied diabetes-prone mice that lacked a bacteria-recognizing part of the immune system and found that they developed the disease at different rates, depending on the cleanliness of their environment.
Mice raised in a germ-free environment developed severe diabetes. Those exposed to healthy bacteria, also known as probiotics, which are normally found in human (and animal) intestines, were less likely to develop the disease, according to the research in the journal Nature.
Next page: The hygiene hypothesis

Comments (3)
My 11 year old daughter was very recently diagnosed with type 1 diabetes, and I agree completely with the hypothesis of this study, that children in modern American culture might be too shielded from the general exposure that builds immunities. However, it’s personally frustrating because all my children were breastfed until they could walk (12-14 months) and raised with the attitude that a little dirt is a good thing to eat. My diabetic daughter is otherwise healthy and very active – it’s just one of those things that she has this particular auto-immunity and we look forward to the day when all auto-immune disease are better understood and ultimately curable.
I was diagnosed with Type 1 at the age of 37, in 1998. I think this is an interesting study, and, while it may not be the only reason the auto-immune system turns against the body, it really makes sense. I hope to see more information on this in the future.
I myself have Type I diabetes. My mother was and still is a very clean person. As a child I was kept as clean as possible, never being allowed to play in dirt. Now at 30 years of age, I start to wander if my diabetes came from genetics or a virus as the doctors told my parents when I was diagnosed at age 6. The advances that have been made since my diagnosis have been great, although I am still waiting for a machine that tests blood sugar levels without a drop of blood. I love learning all I can and hearing from others with the same problems.