Influence of dietary tryptophan content on the activity of Inflammatory Bowel disease.

TANTUCCI LA, CABRERA D, FERNÁNDEZ M, CABANILLAS M, FOCHESATO A, DELGADO A, CORREA SG, BALDERRAMO DC, ROMAGNOLI PA.

Congreso; Reunión de Sociedades de Biociencias-LXV Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC)-LXVIII Reunión Anual de la Sociedad Argentina de Inmunología (SAI)-Reunión Anual de la Sociedad Argentina de Fisiología (SAFIS); 2020

Sociedad Argentina de Inmunología

Dietary tryptophan is catabolized by the intestinal microbiota intometabolites such as indoles and their derivatives. Our hypothesis proposes that a reduced availability of tryptophan metabolites atthe interface of the intestinal mucosa causes a dysregulation of theepithelial barrier that results in Inflammatory Bowel Disease (IBD).To test this hypothesis, we evaluated the content of dietary tryptophan, the circulating tryptophan in plasma and the presence of urinary tryptophan metabolites in 11 control volunteers, 15 patientswith Ulcerative Colitis (UC) and 10 patients with Crohn?s Disease (CD). Daily tryptophan intake was calculated based on a food survey by a nutrition health professional, plasma tryptophan levels weremeasured using high performance liquid chromatography (HPLC) and tryptophan metabolites were determined in urine using mass detector coupled gas chromatography (GC-MS). IBD activity in patients was clinically estimated using the Mayo index (UC) or the Harvey-Bradshaw index (CD). Dietary and plasmatic tryptophan levels were comparable in all the study groups. The amount of tryptophan consumed was directly correlated with the excretion values detected for the tryptophan metabolite 1H-indole-2,3-dione (r = 0.7631, p = 0.0168). In addition, non-tryptophan derived metabolites such as citric acid or 2-hydroxybutyric acid were able to discriminate patientswith IBD from the control group. Although the amount of tryptophan consumed was not related to the activity of IBD in patients with UC, we found that the amount of tryptophan consumed was inversely correlated with the stage of IBD in patients with CD (r = -0.6971, p= 0.0251). Our findings suggest that increasing the amount of tryptophan in the diet may decrease IBD activity in patients with CD and that metabolomic profile of patients with IBD can provide a newprecision medicine tool to improve the management and the quality of life of patients with IBD