The Bioenergetic Architecture of Metabolic Regulation: From Gut–Brain Signalling to Next-Generation Peptide Pharmacology

Energy homeostasis arises from a complex interplay between gut-derived hormones, the central nervous system, and pancreatic function. Beyond the classical incretin axis, a broad spectrum of gut peptides acts in concert to coordinate appetite regulation, nutrient sensing, gastric motility, and systemic bioenergetic balance. Perturbation of this network contributes to metabolic disorders such as obesity, type 2 diabetes, and cachexia, underscoring its pivotal role in physiological and pathological energy regulation. This review provides an integrated analysis of the mechanisms through which gut–brain–pancreas communication maintains metabolic homeostasis, with particular attention to the dynamic cross-talk between peripheral endocrine signals and central regulatory circuits. Alterations in these pathways are examined in relation to their impact on energy expenditure and substrate utilisation, alongside recent translational efforts exploiting multi-receptor peptide agonism and combinatorial hormonal modulation to restore metabolic equilibrium. Emerging therapeutic approaches increasingly aim to engage multiple bioenergetic pathways simultaneously, supported by advances in peptide engineering and molecular design. By conceptualising metabolic regulation as a coordinated network rather than a linear hormonal cascade, this article delineates a physiological and translational framework for next-generation interventions targeting bioenergetic dysfunction in human disease.