A recent study conducted by the Leibniz Institute for Food Systems Biology at the Technical University of Munich has revealed that bitter tasting protein fragments, known as peptides, are produced in the stomach during the digestion of the natural sweetener thaumatin. These peptides are shown to stimulate acid secretion in human stomach cells and influence inflammatory reactions. Veronika Somoza, the lead researcher of the study, highlights that understanding the health effects of thaumatin is crucial given its widespread use as a sweetener.
The research team, led by Veronika Somoza, focuses on investigating how bitter compounds in food impact the metabolism of stomach cells and overall health. Through the establishment of a human gastric cell line test system, the team has previously shown that certain bitter substances can interact with bitter taste receptors in stomach cells, leading to increased acid production. This includes peptides produced during the digestion of milk protein. Building upon these earlier findings, the team explored the potential physiological effects of bitter tasting peptides created during the digestion of thaumatin.
Through studies involving pigs, in vitro experiments, and sensory tests, the research team identified three bitter-tasting peptides produced during the digestion of thaumatin in the stomach. These peptides were found to stimulate the release of protons from stomach cells at very low concentrations. Moreover, the team investigated the anti-inflammatory properties of these peptides by examining how they affected gastric cell reactions to Helicobacter pylori proteins, a bacterium associated with inflammatory stomach diseases and stomach cancer. The results showed that adding one of the bitter peptides could reduce the release of pro-inflammatory interleukin and involve the stomach cell’s own bitter taste receptor in the process.
The study’s findings suggest that the concentration of bitter peptides tested is realistic and can be reached in the stomach through the consumption of a commercially available sweetener tablet. This implies that the anti-inflammatory potential of thaumatin and its bitter cleavage products, as well as the functions of endogenous bitter taste receptors, warrant further investigation. Understanding the molecular mechanisms of diet-related inflammatory gastric diseases, especially those related to Helicobacter pylori infections, is a key focus for ongoing research by the team at the Leibniz Institute.
Thaumatin, a protein naturally found in the West African Katemfe fruit, is known for its sweetening properties and flavor-enhancing effects. Approved as a sweetener in the EU, it is commonly used in various foods and beverages due to its intense sweetness. While its energy content is minimal, thaumatin’s sweetening power diminishes when exposed to heat, though its flavor-enhancing qualities remain intact. The body breaks down thaumatin completely, making it safe for consumption even at higher levels. As such, no Acceptable Daily Intake (ADI) value has been set for thaumatin.
The study, conducted in collaboration with the Technical University of Munich (TUM), was funded by the Leibniz Institute and TUM. Published in the journal Food Chemistry, the research sheds light on the formation of bitter peptides during the digestion of thaumatin in the stomach, their impact on acid secretion and inflammatory reactions, and the potential therapeutic implications for inflammatory gastric diseases. Further exploration of the role of bitter taste receptors in stomach cells and the health effects of sweeteners like thaumatin is crucial for understanding diet-related inflammatory conditions and infections such as those caused by Helicobacter pylori.