Researchers at the University of Oregon have discovered a protein in the guts of zebrafish that has the power to boost insulin production. The protein triggers beta cells in the pancreas to multiply when the fish are in the larval stage.
Since beta cells produce insulin, which in turn regulates blood sugar, the discovery could offer a new approach to fighting diabetes. Type 1 diabetes, which affects 1.5 million people in the U.S. alone, is marked by a loss of beta cells.
The key will be to figure out how gut bacteria—known by scientists as microbiota—impact beta cell development, said Karen Guillemin, a biologist at the University of Oregon and co-author of a paper about the discovery published in eLife. "We're realizing that the microbiome is a rich source for discovering new biomolecules that have enormous potential for manipulating and promoting our health," she said in a press release from the university.
Guillemin and her team took one set of fish and deprived them of specific gut bacteria during the first week of life. Those fish did not experience the same expansion of beta cells as did the fish that were reared normally, meaning they were exposed to those bacteria, according to the release.
From there, they began searching for a bacterial protein that could stimulate beta cells on its own. They winnowed down a list of 163 prospects, using genome analysis to land on one that seemed to have a natural ability to cause beta cells to multiply. They purified the protein and added it back to their germ-free fish, after which they observed that beta cells were starting to grow. They named the protein Beta Cell Expansion Factor A, or BefA.
"This is a new idea that the microbiome could be a source for signals for the development of the pancreas," Guillemin said. "This is the first time that anyone has made a connection between the microbiome and the development of beta cells."
Scientists around the world are investigating several potential methods for enhancing beta cell activity. University of North Carolina at Chapel Hill and North Carolina State University scientists are working on a patch that contains insulin-secreting beta cells. And Harvard scientists have been developing methods for coaxing embryonic stem cells to transform into beta cells.
The next step for the Oregon scientists will be to figure out the mechanism by which BefA stimulates beta cells, according to the statement, and then to test the protein in other animals, including humans.