Bacteria engineered to treat constipation
When it comes to treatments for constipation, the options aren't plentiful, nor are they always particularly effective. Help may be on the way, however, in the form of genetically-engineered bacteria.
Traditionally, people with constipation have been advised to alter their diet, or to try taking probiotics (live bacteria that can help with digestion).
According to the Mayo Clinic's Dr. Purna Kashyap, the problem with both of these approaches lies in the fact that each of us has a unique gut microbiome – that's the community of bacteria that live in the stomach and intestines. As a result, no single change in diet or type of probiotic will work for everyone.
With that in mind, a team led by Kashyap engineered Bacteroides thetaiotaomicron to produce large amounts of a chemical known as tryptamine.
"Tryptamine is similar to the chemical serotonin, which is produced in our gut," he explains. "In this study, we found tryptamine can activate a receptor in the mouse gut that normally responds to serotonin, causing increased secretion of fluid from the lining of the colon. Bacteria can direct the colon to secrete water via tryptamine acting on a host receptor in mice. This accelerates the movement of food through the digestive system."
Additionally, tryptamine produced by the bacteria quickly biodegrades within the intestine, and appears not to accumulate in the bloodstream. This means that unlike some existing constipation medications, it shouldn't cause side effects in other parts of the body.
Further research is being planned, although clinical trials on humans probably won't be happening for at least three years.
A paper on the study was recently published in the journal Cell Host and Microbe.
Source: Mayo Clinic