Taste Sensors in the Gut Could Help Fight Obesity
European researchers examine how malfunctioning nutrient sensors in the gut could be responsible for obesity and other metabolic conditions.
--by Suzanne Boothby
With nearly two-thirds of American adults and one-third of American children overweight or obese, experts wonder what it will take to reverse this epidemic.
Scientists are taking a closer look at taste—not just in the mouth, but also in the gut. New research published this week in the Cell Press journal Trends in Endocrinology & Metabolism says that targeting taste sensors in the gut may be a promising new strategy to fight obesity.
The gut "tastes" what we eat, including the major flavors—bitter, sweet, fat, and savory—in much the same way as the tongue and through the use of similar signaling mechanisms. When food reaches the gut, it releases to control satiety and blood sugar levels.
The sensors, or receptors, in the stomach respond to excess food intake, and their malfunction may play a role in the development of obesity, diabetes, and related metabolic conditions.
The Expert Take
Dr. Sara Janssen and Dr. Inge Depoortere, of the Translational Research Center for Gastrointestinal Disorders at the Catholic University of Leuven, Belgium, said growing evidence suggests that obesity and related conditions might be prevented or treated by selective targeting taste receptors on cells in the gut to release hormones that signal a feeling of fullness. This feeling would mimic the physiological effects of a meal and fool the body into thinking it has eaten.
"The effectiveness of bariatric surgery to cause profound weight loss and a decrease in the prevalence of diabetes and other obesity-related conditions is not completely understood, but it may involve changes in the release of gut hormones," Dr. Depoortere said. "Targeting extra-oral taste receptors that affect the release of hormones that control food intake may offer a new road to mimic these effects in a nonsurgical manner."
Dr. Robert Margolskee, a molecular biologist from Monell Chemical Senses Center and world-renowned expert on the molecular mechanisms of taste, focuses his work on “taste cells of the gut.” In 2007, he published work shedding light on how the gut "tastes" nutrients.
"We now know that the receptors that sense sugar and artificial sweeteners are not limited to the tongue,” he said in a 2007 statement. “Our work is an important advance for the new field of gastrointestinal chemosensation—how the cells of the gut detect and respond to sugars and other nutrients.”
He said that the gut's taste cells regulate the secretion of insulin and hormones that regulate appetite.
Source and Method
Janssen and Depoortere mapped the current understanding of chemosensation in the tongue and gut. A simplified model of the pathways involved in chemosensory signaling in the gastrointestinal mucosa is presented in the current study.
Future studies may reveal which of these gut nutrient receptors are potential drug targets for the treatment and prevention of obesity and diabetes. Until then, education on diet and lifestyle will continue to help steer those looking to lose weight.
A 2007 study in the Journal of Clinical Investigation examined satiation from the standpoint of neural and humoral signals in the gut and how this process could aid in the development of new anti-obesity therapies.
In 2008, researchers from the National Institutes of Health and the Mount Sinai School of Medicine identified taste cells in the gut and further explored the field of gastrointestinal chemosensation.