Have we become so scared of infections that we’ve become a nation of “germaphobes”… at the expense of our health? In a new research study reported in the journal Nature, non-obese diabetic (NOD) mice exposed to “friendly” bacteria—known as probiotics—were shielded from developing the autoimmune disease known as Type 1 diabetes.

The results of this study conducted at Yale University and the University of Chicago support the “hygiene hypothesis”—the theory that a lack of exposure to bacteria and viruses in the developed world may lead to increased risk of allergies, asthma and other immune system disorders.

The findings also propose that exposure to some forms of healthy bacteria normally found in human and animal intestines might help prevent the onset of Type 1 diabetes.

And according to The Centers for Disease Control and Prevention (CDC), there are nearly 2.4 million Americans with Type 1 diabetes. In Type 1, or insulin-dependent diabetes, your own immune system attacks the insulin-producing cells in the pancreas, causing the pancreas to produce less insulin than the body needs, or none at all.

The theory is that because we are unlikely in the developed world to encounter many germs because of cleanliness, there is a much greater chance that our immune systems will attack us instead!

Symptoms of Type 1 diabetes may include…

• Extreme thirst
• Weight loss (without trying)
• Frequent urination
• Hunger (more than normal)

When the body does not have enough insulin—or glucose—cells can’t get the sugar they need to use for energy, and too much sugar builds up in the blood. Over time, this disease can cause damage to the heart, eyes, kidneys, blood vessels and nerves.

But in the new study, Yale lead researcher Li Wen, and University of Chicago lead researcher Alexander V. Chervonsky, found that by exposing NOD mice to probiotics normally found in the intestine, they were much less likely to become diabetic. However, when they raised the mice in a germ-free environment without any of the “friendly” gut bacteria, the mice developed severe diabetes.

“Understanding how gut bacteria work on the immune system to influence whether diabetes and other autoimmune diseases occurs is very important,” Wen said in the journal Nature. “This understanding may allow us to design ways to target the immune system through altering the balance of friendly gut bacteria and protect against diabetes.”