Yeast peptides induce satiety in rats and humans and activate neuronal pathways in brainstem and hypothalamic areas involved in satiety in rats

Abstract

Yeast‐derived peptides were previously shown to display a high satiating effect. This work evaluate their effect i) on food intake in rats as well as in humans, and ii) on the activation of brain neuronal pathways involved in food intake including the Nucleus of the Tractus Solitary (NTS) and the Arcuate Nucleus of the Hypothalamus (Arc). Food intake in rats and humans: The ingestion of a daily load of yeast peptides induced a decrease in daily food intake in rats and in humans after a two‐week habituation period. This decrease did not occurred during the meal following the load (lunch in humans) but several hours later in rats (−16% of control group daily intake) and during the diner in humans (−13% of control group daily intake). Activation of neuronal pathways in rats: After habituation period, yeast protein loads induced an increase in melanocortin pathway within the Arc, which regulates long‐term energy intake, whereas activation of the Glucagon Like Peptide‐1 (GLP‐1) pathway within the NTS, which is triggered during aversive‐induced anorexia, was not increased. Conclusion: Yeast peptides induced a strong food intake suppressing effect in rats and in humans. This effect was not compensated during the rest of the day and did not disappear after habituation. It did not result from a conditioned taste aversion and might be related to a stronger activation of arcuate melanocortin pathway.