For their current investigation, they chose to engineer a strain of the common gut bacterium E. coli that is prescribed as a digestive probiotic in Europe. They inserted genes for hunger-suppressing molecules called NAPEs, which are usually produced in the gut in response to feeding.
To test out these microbes, the scientists added them to the drinking water of mice fed a high fat diet and then compared them to control animals who were just given plain water. They found that the treated mice ate less than control mice, gained 15% less weight and did not develop diabetes.
Although these early results are promising, the researchers still have a long way to go. The treatment has only been tested in mice, and many more pre-clinical trials will be required before FDA approval for human studies will be granted.