JDRF Research

JDRF-Funded Study Links 'Hygiene Hypothesis' to Diabetes Prevention

A research study funded by JDRF suggests that common intestinal bacteria may provide some protection from the development of type 1 diabetes. The findings provide an important clue toward understanding how and why type 1 diabetes develops and may lead to potential treatments and cures. The study, reported this past October in the journal Nature, lends further support to the “hygiene hypothesis,” which postulates that exposure to an appropriate amount and variety of bacteria, viruses, and other microorganisms may be important to living a healthy life, and that susceptibility to type 1 diabetes and other autoimmune disorders may actually be caused by a lack of exposure to these agents.

In this research, teams led by Li Wen at Yale University School of Medicine and Alexander V. Chervonsky at the University of Chicago studied mice that under normal conditions would not develop diabetes. When raised in a germ-free environment, however, these mice developed severe diabetes. The researchers were able to establish that the microbial environment was responsible for this difference because mice that were exposed to common intestinal bacteria maintained a lower risk for the disease. (The bacteria the mice were exposed to were actually harmless microbes that are often found in the human intestine.)

The study’s findings suggest that the interaction between intestinal microbes and the early immune system can somehow modify the risk for type 1 diabetes. In these experiments, exposure to certain bacteria triggered an immune system response in the mice. That response, although not fully understood, is believed to be what prevents autoimmune disorders. The scientists thus suggest that safe, measured exposure to certain bacteria may indeed lower the risk of immune disorders.

“This study outcome gives us a new avenue to explore,” said JDRF executive vice president of research Richard A. Insel, M.D. “With type 1 diabetes in the U.S. and in many countries around the world at about a three percent annual rate, every lead is significant. The research gives impetus to better understanding how the bacterial flora in our body influences host immune defenses and responses that provide resistance to the development of type 1 diabetes. This understanding may suggest new therapeutic approaches to prevention.”