According to a new study, long-term exposure to toxins generated by specific bacteria may lead to type 2 diabetes. The study was conducted by researchers at the University of California, San Francisco (UCSF). They found that mice exposed to high levels of carbon monoxide for several weeks developed many of the symptoms of type 2 diabetes including increased blood sugar, insulin resistance, and obesity. The team also observed changes in the composition of their gut bacteria which may have played a role in causing the disease. Diabetes is caused by defects in insulin production or its use by body cells. There are two main types of diabetes: Type 1 and type 2. With type 1 diabetes, the body does not produce any insulin. With type 2 diabetes, even though the body still produces some insulin, it fails to use it properly resulting in rising blood sugars. Around half of all cases of diabetes are type 2. Risk factors for developing type 2 diabetes include being overweight or obese, having a family history of the disease, age, ethnicity, gender, low physical activity, smoking, and stress. Toxins can be natural substances such as pesticides or herbicides, or they can be man-made chemicals such as those found in cleaning products or vehicle emissions.