Gut Bacteria and T1D: Is there a Link?

Do gut bacteria influence type 1 diabetes risk? Scientists have a hunch they may. 

In Canada, there are an estimated 300,000 men, women and children living with type 1 diabetes (T1D) – and this number is increasing at an alarming rate.¹ In fact, Canada has one of the highest rates of type 1 diabetes for children under 14 years of age.^2,3 

Researchers aren’t sure exactly why the incidence is rising, but new evidence suggests that the community of microbes that inhabit our intestines (gut microbiome) may play a role in the development of a number of autoimmune diseases including type 1 diabetes (T1D).

Scientists have been working to understand why autoimmune diseases have increased in frequency over the past 70 years, says Dr. Jayne Danska, Principal Investigator at Toronto’s Hospital for Sick Children. Dr. Danska is an expert on the gut microbiome – specifically how these organisms regulate our immune systems in health and disease.  

One theory to explain the increased frequency of autoimmune diseases is known as the “hygiene hypothesis”. It suggests that the increase is associated with improved public health measures. These have improved human health, but also decreased exposures to microbes that help establish immune function. 

Simply put, early childhood exposures to microbes help to build a strong immune system, which fights dangerous infections and also limits allergic and autoimmune diseases like T1D, explains Dr. Danska. Our enthusiasm to limit childhood exposures to bacteria may be increasing our vulnerability to diseases like T1D.

To test this theory, a team of JDRF-funded scientists are following over 1000 newborns in three neighboring regions of Finland, Russia and Estonia who are at high genetic risk for T1D and examining differences in the babies’ microbiome, and environmental and social conditions over the first three years of their lives. 

Early results of this study show that babies from the region of Russia do indeed have differences in the composition of gut bacteria compared to infants from Finland. This difference may be related to the 7-times lower incidence of T1D and other immune diseases in Russia compared to Finland. 

“It’s not clear why the microbiome of the Russian children is different,” says Dr. Danska, but she notes that in the area of Russia under study, public health standards differ from Finland, for example most people drink water from wells that has not been treated. 

Currently there is not enough evidence to suggest that we should in alter our exposure to microbiomes to prevent T1D. The rapid pace of research in this area will provide valuable insight into the microbiome and its relationship to T1D, which could lead to viable prevention strategies within the next 5 years. 

1. Jakobsen, T. A. (2016). Psychosocial experiences of type 1 diabetes diagnosed in emerging adulthood (T). University of British Columbia. Retrieved from https://open.library.ubc.ca/cIRcle/collections/24/items/1.0308604 (Original work published 2016)
2. DIAMOND Project Group. Incidence and trends of childhood Type 1 diabetes worldwide 1990-1999. Diabet Med. 2006;23(8):857-866.
3. Karvonen M, Viik-Kajander M, Moltchanova E, Libman I, LaPorte R, Tuomilehto J. Incidence of childhood type 1 diabetes worldwide. Diabetes Mondiale (DiaMond) Project Group. Diabetes Care. 2000;23(10):1516-1526.

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