Fernstrom et al explained that taste buds are made up of a group of taste cells and each individual taste cell expresses only one type of taste receptor. All compounds that are perceived as sweet share one common trait: they bind to and activate the sweet taste receptor on taste cells in the mouth. The authors presented recent research in rodents that has confirmed the presence of sweet receptors in the gut as well. The role of sweet taste receptors in the gut has been linked to what is known as flavor conditioning. Flavor conditioning occurs when the reward system of the brain is stimulated. Animals then developed a preference for foods or drinks where their reward system was stimulated. Fernstrom et al cautioned that, “Although rodents have proven to be an excellent model system for understanding the molecular basis of sweet taste, rodents and humans differ in their perception of both nutritive sweeteners and LCS [low calorie sweeteners].”
It has been hypothesized that low calorie sweeteners (LCS) interact with the sweet taste receptors in the gut, and disrupt the glucose balance by promoting glucose uptake into tissues when sugars have not been consumed, and that this could lead to increased appetite and greater food intake. The research reviewed by the authors, however, contradicts this hypothesis. Fernstrom et al noted that, “Although this chain of events has not been directly tested, many findings, especially in human participants, suggest that it is unlikely to occur.”
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