Type 1 diabetes originates in the gut but probiotics could offer cure

Two separate pieces of research have found that the development of Type 1 diabetes is likely caused by the gut, and therefore, a type of probiotic could be the cure.

Scientists from several European and US institutions studied 33 Finnish infants over three years from birth who were genetically predisposed to type 1 diabetes.

Their study, entitled "The Dynamics of the Human Infant Gut Microbiome in Development and in Progression toward Type 1 Diabetes" is published in the journal Cell Host & Microbe.

They discovered that four children in the group that developed type 1 diabetes had 25% less types of bacteria in their guts than other children.

The same four infants were also found to have more amounts of a specific bacteria that is known to trigger gut inflammation. This could be a prelude to type 1 diabetes as the bacteria causes the immune system to mistakenly attack and destroy beta cells in the pancreas that usually make insulin and monitor glucose levels.

"We know from previous human studies that changes in gut bacterial composition correlate with the early development of type 1 diabetes, and that the interactions between bacterial networks may be a contributing factor in why some people at risk for the disease develop type 1 diabetes and others don't," said Jessica Dunne, Director of Discovery Research at Juvenile Diabetes Research Foundation (JDRF), a UK charity which funded the study.

"This is the first study to show how specific changes in the microbiome are affecting the progression to symptomatic T1D."

By being able to understand how the community of microorganisms in our guts (known as a microbiome) and which species are absent in the gastrointestinal tracts of children, the researchers believe they can slow down the progression of type 1 diabetes.

Probiotics could be the cure for type 1 diabetes

Cornell University researchers have a similar idea, but they have been working on a treatment that involves regulating insulin by engineering the bacteria found in our guts.

Their study, entitled "Engineered Commensal Bacteria Reprogram Intestinal Cells Into Glucose-Responsive Insulin-Secreting Cells for the Treatment of Diabetes" is published in the journal Diabetes.

The scientists took a strain of bacteria known as Lactobacillus gasseri – a type of bacteria found in probiotic yoghurts – and engineered the bacteria to be able to secrete a hormone called glucagon-like peptide-1 (GLP-1).

When they fed this engineered probiotic to a group of diabetic rats for 90 days, they discovered that the bacteria triggered the upper intestinal epithelial cells in the rats to convert into cells that acted a lot like the pancreatic beta cells.

The rats had up to 30% lower high blood glucose than diabetic rats that did not receive the probiotic, and the probiotic was shown to reduce glucose levels in diabetic rats the same way the levels would be reduced in normal rats.

"The amount of time to reduce glucose levels following a meal is the same as in a normal rat... and it is matched to the amount of glucose in the blood. It's moving the centre of glucose control from the pancreas to the upper intestine," said John March, professor of biological and environmental engineering at Cornell University and the paper's senior author.

The next step for March and his team is to prove that their method of engineering bacteria to move insulin production to the intestine will work in humans too.

They aim to develop a pill that patients suffering from both type 1 and type 2 diabetes can take daily, that will be available within the next two years.