Effect of whole foods on the microbial production of tryptophan-derived aryl hydrocarbon receptor agonists in growing pigs

• Published in: Food chemistry 2023-08, Vol.416, p.135804-135804, Article 135804
• Main Authors: Huang, Zhan, de Vries, Sonja, Fogliano, Vincenzo, Wells, Jerry M., van der Wielen, Nikkie, Capuano, Edoardo
• Format: Article
• Language: English
• Subjects: animal models; Animals; Aryl hydrocarbon receptor; aryl hydrocarbon receptors; cell lines; Colon; digesta; feces; food chemistry; food choices; Food matrix; ileum; indole acetic acid; Indole derivatives; Indoles; Kynurenine; ligands; metabolites; Receptors, Aryl Hydrocarbon - metabolism; serotonin; Skatole; Small intestine; Swine; tryptamine; Tryptophan; Tryptophan - metabolism
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2023.135804

•Level of tryptophan catabolites produced in the whole intestine of pigs was measured.•Food matrices induce different panels of microbiota-derived tryptophan catabolites.•Food matrices influence the content of tryptophan available in the intestinal lumen.•Indole-3-lactic acid is mainly produced in the small intestine.•Skatole, oxindole, serotonin, and indoleacrylic acid are only produced in the colon. Effects of whole foods on the microbial production of tryptophan-derived aryl hydrocarbon receptor (AhR) ligands in the intestine were investigated in a pig model. Ileal digesta and faeces of pigs after feeding of eighteen different foods were analyzed. Indole, indole-3-propionic acid, indole-3-acetic acid, indole-3-lactic acid, kynurenine, tryptamine, and indole-3-aldehyde were identified in ileal digesta, which were also identified in faeces but at higher concentrations except indole-3-lactic acid, together with skatole, oxindole, serotonin, and indoleacrylic acid. The panel of tryptophan catabolites in ileal digesta and faeces varied across different foods. Eggs induced the highest overall concentration of catabolites in ileal digesta dominated by indole. Amaranth induced the highest overall concentration of catabolites in faeces dominated by skatole. Using a reporter cell line, we observed many faecal samples but not ileal samples retained AhR activity. Collectively, these findings contribute to food selection targeting AhR ligands production from dietary tryptophan in the intestine.