Fecal Amino Acid Analysis Can Discriminate De Novo Treatment‐Naïve Pediatric Inflammatory Bowel Disease From Controls

Abstract

Significantly increased levels of six different fecal amino acids were found in patients with IBD compared to controls. Whether these differences reflect decreased absorption or increased loss by inflamed intestines needs to be elucidated.

Integrated metabolomics and proteomics of symptomatic and early pre-symptomatic states of colitis

“…No specific role is yet reported for alanine. Whether these differences reflect decreased absorption or increased loss by inflamed intestines needs to be elucidated, but is consistent with previous findings on pediatric IBD patients (Bosch et al, 2018).…”

Characteristics of fecal metabolic profiles in patients with irritable bowel syndrome with predominant diarrhea investigated using 1H‐NMR coupled with multivariate statistical analysis

“…Phenylalanine was identified as a major fecal metabolite in IBS, and phenylalanine metabolism was the most relevant pathway influenced by IBS . Phenylalanine is liphophilic and aromatic amino acid which influence membrane diffusion and transportation . A previous study showed that phenylalanine increase membrane permeability.…”

Reply

“…This scenario is highly similar to other chronic inflammatory diseases (eg, rheumatoid arthritis 3 or the metabolic inflammation seen in obesity 4 ), where no intestinal leakage or malabsorption is expected. Second, in the study by Lamas et al in adult patients with IBD, a highly significant decrease of fecal TRP levels was observed, 5 which may represent a difference between adults and the pediatric patients investigated by Bosch et al 2 We value the thoughts of Bosch et al regarding the relationship between interleukin (IL)-22 levels and TRP metabolites. Indeed, we were able to confirm elevated IL-22 concentrations in active IBD, as previously reported.…”

“…Bosch et al have recently extended our observation of low systemic tryptophan (TRP) levels in inflammatory bowel disease (IBD) 1 by showing increased levels of TRP and 4 other aromatic amino acids in the stools of 30 pediatric patients with IBD. 2 They suggested a disturbed host-microbiota interaction as a mechanism. In their letter, they propose that colonic leakage and malabsorption rather than increased metabolism may explain the lowered systemic TRP levels in patients with IBD.…”

“…LT is a relevant option for cure in patients with HCC if transplant criteria adhere to restrictions based of tumor characteristics rather than liver function. 2 After all, the Milan criteria improved post-LT patient survival worldwide through drastic reduction of the posttransplant HCC recurrence rates. Introducing "HCC-specific survival" as primary end point in the Metroticket study aimed at maintaining survival as primary end point while dissecting-through competitive risk analysis-the tumorrelated causes of death after transplant.…”