Bugs in the GI Tract: The Microbiome's Link to Diabetes

Robert Ratner, MD; Mark Harmel, MPH


June 28, 2016

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We have known for a very long time that genes and the environment interact to cause both type 1 and type 2 diabetes. Little did we know that part of that environment is inside us, in what is called our microbiome—all of the bugs that populate our gastrointestinal (GI) tracts.

Over the past several years, we have learned that the type of bugs and even the number of bugs in our GI tract have an effect on autoimmunity. Thus, the relationship among certain bugs in the GI tract—and in particular the diversity of bugs in our GI tract—clearly has an impact on autoimmunity and the ability to identify self or not identify self.

Many autoimmune diseases, including type 1 diabetes, appear to be related to characteristics of the microbiome. This gives us another opportunity to potentially intervene to block the immunologic attack on the islet cells simply by manipulating the bugs in our GI tract.

In addition, we have found a clear relationship between the microbiome and obesity and type 2 diabetes. Again, a high number of bugs and a highly diverse microbiome seem to protect us from obesity and type 2 diabetes. Moreover, certain bugs that cause a markedly increased risk of developing type 2 diabetes are now being identified.

This field is in its absolute infancy. We need to develop standardization of collection of samples and standardization of analysis of these samples, and we need to get beyond the epidemiology and simply looking at relationships and associations so that we can begin to focus on causation. We need to learn the specific bacterial or viral ingredients that seem to trigger either the autoimmunity or the changes in metabolism.

We are a long way from doing that; however, just recently, the federal government announced the National Microbiome Initiative, with $121 billion being put into play to help us understand the relationship of our interior environment and the development of disease.


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