Dose-Dependent Enhancement of L-Tryptophan-Induced Gut Hormone Secretion and Appetite Suppression by Intraduodenal Calcium in Obesity

Study Background and Disease Burden

Obesity is a major global public health challenge, associated with increased morbidity and mortality due to its link to cardiometabolic diseases, type 2 diabetes, and certain cancers. Managing energy intake and appetite is central to obesity treatment strategies. Gut-derived hormones such as cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine-tyrosine (PYY) are critical regulators of satiety, gastric emptying, and energy homeostasis. Nutritional interventions that modulate these gut hormones have shown promise in appetite control. L-tryptophan (Trp), an essential amino acid, has anorexigenic properties mediated partly by releasing these satiety hormones. Prior research in lean male individuals demonstrated that intraduodenal calcium enhances the suppressive effects of Trp on energy intake, implicating calcium’s role in gut hormone modulation. However, this interaction’s efficacy and dose-dependence in individuals with obesity, who often exhibit altered gut hormone responses, remains poorly understood. Elucidating these mechanisms is essential to explore novel, safe strategies to augment appetite regulation in obesity management.

Study Design