Could a probiotic pill cure diabetes?

More than 29 million people in the USA have diabetes, and it is the seventh-leading cause of death in the country. But could a cure be on the horizon? 

According to researchers from Cornell University in Ithaca, NY, it could - in the form of a probiotic pill.

Using engineered human gut bacteria, researchers were able to reprogram the cells of diabetic rats to produce insulin. Pictured is a reprogrammed rat cell; the green coloring shows insulin.
Image credit: Diabetes journal/Cornell University

In a proof-of-principle study published in the journal Diabetes researchers at Cornell reveal how they were able to reduce blood glucose levels in diabetic rats using a common bacteria found in the human gut.

Diabetes is a condition in which the pancreas is either unable to produce enough of the hormone insulin, the body's cells do not effectively respond to the hormone, or both.

As a result, blood glucose levels rise higher than normal - known as hyperglycemia. 

This can cause a number of complications, including stroke, heart disease and nerve damage.

Diabetes prevalence has risen in the US in recent years, increasing from 25.8 million people affected in 2010 to 29.1 million in 2012.

But with the findings of their study, March and colleagues say they may be one step closer to a cure for the condition.

The researchers engineered a common strain of "friendly" human gut bacteria called Lactobacillus to secrete Glucagon-like peptide 1 (GLP-1) - a hormone that releases insulin in response to food.

Lactobacillus is a probiotic often used to prevent and treat diarrhea, as well as irritable bowel syndrome (IBS),Crohn's disease and some skin disorders.

Engineered probiotic reduced blood glucose levels by up to 30%

Each day for 90 days, the team orally administered the modified probiotic to a group of diabetic rats. They monitored its effects on blood glucose levels, comparing the outcomes with diabetic rats that did not receive it.

At the end of the 90 days, the researchers found the rats that received the modified probiotic had blood glucose levels up to 30% lower than those that did not receive the probiotic.

The team says the probiotic appeared to convert the rats' upper intestinal epithelial cells to cells that acted a lot like pancreatic beta cells, which - in healthy people - secrete insulin and regulate blood glucose levels.

"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, just as it would be with a normal-functioning pancreas. It's moving the center of glucose control from the pancreas to the upper intestine."

On giving the modified probiotic to healthy rats, however, the team found that it did not appear to affect blood glucose levels. If the rat is managing its glucose, it doesn't need more insulin.

The research team says they now plan to test higher doses of the engineered probiotic in diabetic rats in order to see whether it can completely reverse the condition.

They are also working with a biopharmaceutical company called BioPancreate to get the probiotic made into a pill for human use. If successful, the researchers say it would be likely a diabetic would take the pill each morning to help manage their condition.

References:

1.     Engineered commensal bacteria reprogram intestinal cells into glucose-responsive insulin-secreting cells for the treatment of diabetes, John March , et al., Diabetes, doi: 10.2337/db14-0635, published online 27 January 2015, abstract.

2.     Cornell University news release, accessed 30 January 2015 via EurekAlert.