Oral tryptophan activates duodenal aryl hydrocarbon receptor in healthy subjects: a crossover randomized controlled trial
Gaston Rueda, Natalia Causada Calo, Rajka Borojevic, Andrea Nardelli, María Inés Pinto-Sánchez, Marco Constante, Josie Libertucci, Vidhyalakshmi Mohan, Philippe Langella, Linda M. P. Loonen, Jerry M. Wells, Stephen M. Collins, Harry Sokol, Elena F. Verdú, Přemysl Berčík
Abstract
We demonstrate that in healthy subjects, orally administered tryptophan activates microbial indole and host kynurenine pathways in the small intestine, the primary metabolic site for dietary components, and the richest source of immune cells along the gut. This study provides novel insights in how to optimally activate immunomodulatory AhR pathways and indole metabolism in the small intestine, serving as basis for future therapeutic trials using l-tryptophan supplementation in chronic inflammatory conditions affecting the small intestine.