Metabolomic study of a diagnostic model for the metabolites of stool fat.
OBJECTIVE
Metabolomics is a powerful tool for measuring low-molecular-weight metabolites in an organism at a specified time under specific environmental conditions. The aim of this study was to determine the usefulness of metabolomics in identifying the metabolites in stool-fat-positive specimens, and to establish whether the results could be used to predict the long-term prognosis.


METHODS
Fecal specimens were collected from 52 subjects with bowel habit change. The subjects were accessed using Rome III questionnaires and Bristol stool scale form, and followed after three years. The feces samples were centrifuged and the resulting extracts reconstituted for liquid chromatography/mass spectrometry analysis. The datasets were autoscaled, log-transformed, and mean-centered in a column-wise fashion prior to principal-components analysis and partial least-squares-discrimination analysis modeling.


RESULTS
Fecal samples from 10 of the 52 patients gave a positive stool-fat result of 30-100 mm; those of the remaining 42 contained neither fatty acids nor neutral fats. The peak intensities of lithocholic acid (p=0.001), lysophosphatidyl ethanolamine (lysoPE) 16:0 (p=0.015), and lysoPE 18:1/0:0 (p=0.014) were correlated with the size of the fatty acid. Subjects with positive stool-fat result showed higher score in Bristol stool scale form than those with negative stool-fat result at initial (p=0.040) and after three years (p=0.012).


CONCLUSIONS
The metabolomic assay of stool fatty acid revealed mainly lysoPEs and lithocholic acid. The size of the fatty acid was correlated with higher concentrations of lysoPEs and lithocholic acid in stool-fat-test-positive specimens and related to loose stool even after three years of follow-up period.
Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
Choong Hwan
CH
Lee
Jiyoung
J
Kim
Su Young
SY
Ahn
Sun Young
SY
Lee
D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000032:analysis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016018:Least-Squares Analysis; D008095:Lithocholic Acid / Q000032:analysis; D008246:Lysophospholipids / Q000032:analysis; D008297:Male; D055432:Metabolomics; D008875:Middle Aged; D025341:Principal Component Analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D011795:Surveys and Questionnaires
D005227:Fatty Acids; D008246:Lysophospholipids; C008301:lysophosphatidylethanolamine; D008095:Lithocholic Acid