Intestinal Bacteria Helps Prevent Type 1 Diabetes

Exposure to common intestinal bacteria might inhibit the development of type 1 diabetes, according to a recent study. The study results lend support to the more general “hygiene hypothesis,” and could potentially go a long way in explaining, and perhaps preventing, the development of type 1 diabetes.

The hygiene hypothesis, most generally, states that a lack of exposure during childhood to common bacteria and other infectious organisms, might in fact promote the development of certain immune diseases (such as diabetes). In other words, allowing a child to be exposed to these common organisms, might in fact lead to a healthier life in the long run. While definitive support for this belief has been lacking, many medical professionals are believers in some form of the hygiene hypothesis, in principle.

It’s believed by many hygiene hypothesis supporters that throughout the course of human evolution, exposure to certain bacteria and parasites has been common and natural, and in fact a significant part of our development. Due to controlled environments and perhaps excessive concern for child sickness, more and more children lack exposure to these “natural” organisms. It’s thought that this diminished exposure helps explain the rise in autoimmune disorders like type 1 diabetes.

The current study has focused on how exposure to certain bacteria might affect the development and progression of type 1 diabetes in an animal model. Type 1 diabetes, thought to be a highly genetic condition that develops early in life (it’s also known as “juvenile” diabetes), is characterized by the killing of insulin producing pancreatic beta-cells. This is caused by a malfunctioning immune system that attacks the beta-cells.

Results indicated that mice exposed to certain common intestinal bacteria had a lesser chance of developing type 1 diabetes. The bacteria used in the study are common within the human intestinal tract. It’s believed that these bacteria triggered a response from the immune system that also prevents the development of certain immune system disorders, including diabetes. For mice raised in “germ free environments,” there was an observed increase in risk in the development of type 1 diabetes.

The results of this study might be useful in multiple ways, though not a definite solution to any problems in its own right. It does lay the foundations for further research into intestinal bacteria, and their use in preventing autoimmune diseases. Fitting this into the hygiene hypothesis, there is the possibility that controlled exposure to these bacteria in human children can help prevent type 1 diabetes, as well as other dangerous conditions (such as irritable bowel syndrome and multiple sclerosis).

If it is confirmed through further research that exposure to these bacteria helps prevent, and lack of exposure helps cause, type 1 diabetes, than an avenue for understanding this somewhat mysterious disease, might be available. “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 provide new therapeutic approaches to prevention,” concludes researcher Dr. Richard Insel.

Source: Defeat Diabetes Foundation: Insel, Richard. Cook, Michael. Nature news release. October 2008.