Altered tryptophan metabolism in patients with recurrent functional abdominal pain

The causes of functional abdominal pain are still unclear. The role of food factors in their pathogenesis has been assessed by many researches, but the obtained results are varied.The aim of present study was to evaluate metabolism of tryptophan, which is substrate for serotonin synthesis and other bioactive compounds, in patients with recurrent functional abdominal pain.Thirty patients with recurrent abdominal pain and 30 healthy subjects were enrolled in this study. Urinary levels of tryptophan (TRP), 5-hydroxyindoleacetic acid(5-HIAA), L-kynurenine (KYN), xanthurenic acid(XA), and quinolinic acid(QA) were determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and related to creatinine level (mg/gCr), during active phase(day with acute pain), and silence period, which recommended optimalisation of tryptophan intake.5-HIAA/TRP ratio and KYN/TRP ratio as well as QA level s were significantly higher in patients compared to control group (p0.001). After reducing TRP consumption, the above results improved, in particular, the level of QA decreased from 6.88±1.04 mg/Cr to 4,32±0.97 mg/gCr (p0.001).Altered tryptophan metabolism may affect locally-andcentrally mediated recurrent functional abdominal pain.