Nutrient detection pathways for food reinforcement and satiation

Ingested food is broken down into macronutrient components that are detected by gut-brain signaling pathways that play a vital role in feeding behavior. These specialized mechanisms both promote food intake (via appetition and food reinforcement pathways) and terminate food intake (via satiation pathways). Despite recent significant advances in our understanding of gut-brain signaling and behavior, questions remain about the distinct mechanisms mediating food reinforcement and satiation. Here, we review the receptors/transporters and gut-brain pathways that contribute to nutrient sensing and feeding behavior, and highlight key knowledge gaps that will guide future research on the complex gut-brain systems that influence food intake.