A new noninvasive diagnostic imaging tool measures the levels of a naturally occurring enzyme—bile salt hydrolase—inside the body’s entire gastrointestinal tract, research finds.
Inside the human body lives a large microscopic community called the microbiome, where trillions of bacteria engage in a constant “tug of war” to maintain optimal levels of good and bad bacteria. Most of this struggle takes place within the body’s gastrointestinal tract, as bacteria help with digesting food and support the immune system. Although health experts believe good “gut” health is key to a person’s health and well-being, scientists are still developing a detailed picture of what goes on inside a person’s gastrointestinal tract.
“Our imaging tool is a bioluminescent probe in the form of a capsule.”
“Until now, we have not had any ways to noninvasively monitor activity in the intact gastrointestinal tract, given the unique chemical environment, variable distribution and highly dynamic nature of the gut microbiota,” says Elena Goun, an associate professor in the chemistry department at the University of Missouri.
In a new study published in Science Advances, Goun and colleagues describe their work. Goun says their tool accomplishes three major functions:
- Predicts the clinical status of inflammatory bowel disease, such as Crohn’s disease and ulcerative colitis;
- Determines the efficacy of many commercially available probiotic supplements by testing for the level of bile salt hydrolase, which is responsible for all of the major health-promoting functions of probiotics;
- Evaluates whether certain types of prebiotics—dietary fibers known to support digestive health—can increase bile salt hydrolase levels in a similar way that probiotic supplements do.
Goun, who specializes in the development of biomedical imaging tools to advance the knowledge and understanding of various processes underlying human diseases, believes their findings are exciting, especially with the discovery related to prebiotics, which can be naturally found in foods such as whole grains, nuts and seeds, and fruits and vegetables.
“Prebiotics are often used in combination with probiotics to enhance their functions in the body,” Goun says. “We show for the first time that certain types of prebiotics alone are capable of increasing bile salt-hydrolase activity of the gut microbiota, which among other health benefits has been shown to decrease inflammation, reduce blood cholesterol levels, and protect against colon cancer and urinary tract infections. In my opinion, this discovery is huge because the production and storage of prebiotics is less expensive than with probiotics.”
Previous reports have noted high bile salt-hydrolase activity of the gastrointestinal tract is reflective of better digestive health and a lack of inflammation in the body. Goun says their noninvasive method uses bioluminescence—a chemical reaction that produces light inside a living organism—to measure the level of bile salt-hydrolase activity throughout the entire gastrointestinal tract.
“Our imaging tool is a bioluminescent probe in the form of a capsule,” Goun says. “When someone swallows it, it’s exposed to the intact gut microbiota while traveling throughout the harsh environment of a person’s entire gastrointestinal tract. After it passes out of the body, we can analyze a person’s stool sample. We can take the results from that analysis and correlate it with the amount of bile salt-hydrolase activity within the human gastrointestinal tract.”
Goun believes this research could lead to better precision medicine treatments by providing a way for scientists to better understand how a person’s individual gut health is connected to various human pathologies, or the origin and nature of human diseases.
“This is the first example of the use of bioluminescent imaging probes in humans,” Goun says. “The gut microbiome plays a huge role in various health issues such as cancer, diabetes, obesity, Parkinson’s disease, depression, and autism, and now, this new tool will help us better understand the relationship between the gut function and these diseases. In addition, it will allow us to develop more effective probiotics and prebiotics to improve gut health.”
Additional researchers contributed from the Swiss Federal Institute of Technology in Lausanne, Switzerland; Nestlé Institute of Health Sciences in Lausanne, Switzerland; the University of North Carolina at Chapel Hill; and Nationwide Children’s Hospital in Columbus, Ohio.
Source: University of Missouri
