OBJECTIVE: The roles that amino acids play in immunity and inflammation are well 
defined, and the relationship between inflammatory bowel disease (IBD) and 
certain amino acids has recently attracted attention. In this study, the levels 
of amino acids and trichloroacetic acid (TCA) cycle-related molecules in the 
colonic tissues and sera of patients with ulcerative colitis (UC) were profiled 
by gas chromatography/mass spectrometry (GC/MS), with the aim of evaluating 
whether the clinical state induced by UC leads to variations in the amino acid 
profile.
MATERIALS AND METHODS: Colonic biopsy samples from 22 UC patients were used, as 
well as serum samples from UC patients (n = 13), Crohn's disease (CD) patients 
(n = 21), and healthy volunteers (n = 17).
RESULTS: In the GC/MS-based profiling of amino acids and TCA cycle-related 
molecules, lower levels of 16 amino acids and 5 TCA cycle-related molecules were 
observed in the colonic lesion tissues of the UC patients, and the serum 
profiles of amino acids and TCA cycle-related molecules of the UC patients were 
different from those of the CD patients and healthy volunteers.
CONCLUSIONS: Our study raises the possibility that GC/MS-based profiling of 
amino acids and TCA cycle-related molecules is a useful early diagnostic tool 
for UC.