Science may be one step closer to treating diabetes with a human probiotic pill. In the study, published Jan. 27 in the journal Diabetes, the researchers engineered a strain of lactobacillus, a human probiotic common in the gut, to secrete a Glucagen-like peptide (GPL-1). They then administered it orally to diabetic rats for 90 days and found the rats receiving the engineered probiotic had up to 30 percent lower high blood glucose, a hallmark of diabetes.
The study was a proof of principle, and future work will test higher doses to see if a complete treatment can be achieved, said John March, professor of biological and environmental engineering at Cornell University and the paper's senior author.
The researchers found that upper intestinal epithelial cells in diabetic rats were converted into cells that acted very much like pancreatic beta cells, which monitor blood glucose levels and secrete insulin as needed to balance glucose levels in healthy individuals.
"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, March said. "It's moving the center of glucose control from the pancreas to the upper intestine."
Also, though it replaces the insulin capacity in diabetic rats, the researchers found no change in blood glucose levels when administered to healthy rats. "If the rat is managing its glucose, it doesn't need more insulin," March said.