Oral Presentation ESA-SRB-NZSE-CaSR 2026 in conjunction with ENSA

Interaction between calcium and L-tryptophan to modulate gut hormone secretion in health, obesity and type 2 diabetes (143806)

Javad Anjom-Shoae 1 , Simon Veedfald 2 , Michael Horowitz 1 3 , Christine Feinle-Bisset 1
  1. School of Medicine and Centre of Research in Translating Nutritional Science to Good Health, Adelaide University, Adelaide, SA, Australia
  2. Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
  3. Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, SA, Australia

The interaction of dietary nutrients with chemoreceptors in the small intestine leads to the secretion of gut hormones, integral to the regulation of gastric emptying, energy intake and postprandial blood glucose (1). One of these receptors, initially recognised for its capacity to sense extracellular calcium, is the calcium-sensing receptor (CaSR) (2). The CaSR has subsequently been found to also sense aromatic amino acids, including L-tryptophan (L-Trp), with distinct binding sites for calcium and L-Trp (2). A substantial body of preclinical work demonstrated that the CaSR mediates gut hormone secretion in response to L-Trp, an effect promoted by extracellular calcium (2). In humans, while direct confirmation of CaSR involvement in gut hormone release remains to be thoroughly explored, intraluminal administration of calcium has been shown to enhance L-Trp-induced increases in plasma concentrations of a number of gut hormones, including cholecystokinin, glucagon-like peptide-1 and peptide YY, associated with reductions in energy intake, in both healthy individuals (3) and those with obesity (4). Moreover, recent studies have provided evidence that calcium has the capacity to also slow gastric emptying and lower postprandial blood glucose in both health and type 2 diabetes. My presentation will review evidence that calcium, alone and in combination with L-Trp, stimulates gut hormone secretion and modulates gastric emptying, appetite and glycaemia, and considers the alignment of these effects with the proposed dual-ligand engagement of the CaSR. The effects of calcium have implications for the potential development of novel, safe, low-cost, nutrient-based management strategies for obesity and type 2 diabetes.

  1. Anjom-Shoae J, Feinle-Bisset C, Horowitz M (2024) Impacts of dietary animal and plant protein on weight and glycemic control in health, obesity and type 2 diabetes: friend or foe? Front Endocrinol 15:1412182.
  2. Anjom-Shoae J, Veedfald S, Conigrave AD et al (2026) Calcium-sensing receptor regulation of gastrointestinal hormone secretion. Endocr Rev 47:264–279.
  3. Anjom-Shoae J, Fitzgerald PC, Horowitz M et al (2024) Intraduodenal calcium enhances the effects of l-tryptophan to stimulate gut hormone secretion and suppress energy intake in healthy males: a randomized, crossover, clinical trial. Am J Clin Nutr 120:528–539.
  4. Anjom-Shoae J, Fitzgerald PCE, Horowitz M et al (2025) Dose-related effects of calcium to enhance the effects of l-tryptophan on gut hormones and energy intake in obesity. J Clin Endocrinol Metab 110:e2929–e2938.