Microbes & Type 1Diabetes

Type 1 Diabetes (T1D) is an autoimmune disease where inflammation in the Pancreas resulted in certain cells in the immune system attacking beta pancreatic cells that secrete insulin. The damaged, failing beta cells could not produce enough insulin, resulting in insulin deficiency.

An increasing body of research demonstrated that the bacteria in our gut (microbiota) can influence our immune system and inflammation status.

A small human study compared the microbial composition in relation to blood glucose level of T1D versus healthy non-diabetic children. researchers found that the ‘good bacteria’, Bacteroidetes, decreases significantly as blood glucose level increases while  The ‘bad bacteria’, Clostridium, increases significantly as blood glucose level increases in diabetic children. Healthy children have significantly more Bacteroidetes.

“At the genus level, we found a significant increase in the number of Clostridium, Bacteroides and Veillonella and a significant decrease in the number of Lactobacillus, Bifidobacterium, Blautia coccoides/Eubacterium rectale group and Prevotella in the children with diabetes.” The authors added, “Moreover, the quantity of bacteria essential to maintain gut integrity was significantly lower in the children with diabetes than the healthy children.” Since children with diabetes have a higher level of blood sugar compared to the healthy group, the researchers suggested the increase of ‘bad bacteria’ may be related to the glycemic level in the group with diabetes. The study showed Type 1 Diabetes is associated with compositional changes in gut microbiota. [Maria Isabel Queipo et al.]

Viruses are associated with T1D as well. In boys, human parechovirus infection induces a subsequent appearance of diabetes-associated autoantibodies.

Echovirus 4 and Coxsackie B virus are associated with T1D as well. The latter may infect and destroy the insulin producing beta-cells in the pancreas and also damage these cells via indirect autoimmune mechanisms. However, Coxsackie B3 and B6 viruses were found to be associated with a reduced risk of such autoimmunity (possibly due to immune cross-protection against Coxsackie B1 virus).

Not all bacteria and viruses within a particular species are pathogenic. Some are commensal (benign). A Finnish study compared different strains of  Bifidobacteria And found that children who developed islet autoimmunity and T1D later in life showed significantly higher responses and have significantly higher autoantibodies against a bacteria strain, Bifidobacteria adolescentis DSM 20083 proteins .

The researchers pointed out, biochemically detectable autoantibodies can serve as reliable indicator for T1D development. [I Talja - 2014]