Gut flora- Suspects of interest in the cause and treatment of type 1 and 2 diabetes

I previously discussed how an unhealthy gut can cause tissue inflammation and ultimately lead to obesity. Nevertheless, gut microbiota have further reaching effects than just weight gain. According to recent studies, the biological makeup of your gut could play a significant role in the onset of both type 1 and type 2 diabetes. 
The cause of type  1 and 2 diabetes is not explicitly known. Type 1 diabetes is not preventable and often runs in families, but isn't related to lifestyle choices (such as diet and exercise). Type 2 diabetes is preventable and closely related to genetics, high blood pressure, and obesity. However, research suggests that another factor in diabetes could be related to the health and biological makeup of your gastrointestinal tract. 

In the development of type 1 diabetes, there are three crucial factors relating to gut health that interact closely with one another. The microbiota found in the gut (specifically those that trigger inflammation)  play an important role in the formation of autoimmune diabetes. Moreover, it is believed that the interaction of gut bacteria and the mucosal immune system in postnatal development may have long-term effects and implication for the formation of type 1 diabetes later in life (Vaarala, et al. 2008). Another factor is the degree of permeability of the intestinal wall. Those suffering from type 1 diabetes have a more permeable gut than those without the disease. Low levels of a special tight junction protein known as "claudin" cause an increased permeability in intestines of individuals with type 1 diabetes. This extreme permeability not only leads to increase exposure to sugar, but to other dietary antigens that trigger an immune response. Furthermore, an altered mucosal immune system could be a significant factor in failure for the body to form tolerance which consequently lead to autoimmune responses (Vaarala, et al. 2008).


A study investigating the relationship between gut flora and the development of type 2 diabetes discovered that gut flora may play a role in increasing the permeability of the intestinal walls. Mice fed a high fat diet which induced type 2 diabetes showed an increase in adherence of bacteria to the membrane of the intestines. Ultimately, these bacteria are able to move through the membrane and into the adipose tissue (stored fat) as well as the blood (Amar, et al. 2011).  However, with a probiotic treatment (Bifidobacterium animalis subsp. lactis 420), membrane adherence diminished along with the translocation of bacteria to fat cells and blood. Utilizing such probiotics may prove helpful in controlling diet induced diabetes, as inflammation was reversed in this particular study (Amar, et al. 2011).


References:

Amar, J., Chabo, C., Waget, A., Klopp, P., Vachoux, C., Bermúdez-Humarán, L. G., Smirnova, N., Bergé, M., Sulpice, T., Lahtinen, S., Ouwehand, A., Langella, P., Rautonen, N., Sansonetti, P. J. and Burcelin, R. (2011), Intestinal mucosal adherence and translocation of commensal bacteria at the early onset of type 2 diabetes: molecular mechanisms and probiotic treatment. EMBO Mol Med, 3: 559–572. doi: 10.1002/emmm.201100159

Vaarala, O., Atkinson, M. A., & Neu, J. (2008). The "Perfect Storm" for Type 1 Diabetes: The Complex Interplay Between Intestinal Microbiota, Gut Permeability, and Mucosal Immunity.Diabetes, 57(10), 2555-2562.