Table 1.
Change in selected metabolites in nontargeted analyses in plasma and urine
| Metabolite Annotationa | Fold Change | Nominal P Value | Metabolite Descriptionb |
|---|---|---|---|
| Plasma metabolites | |||
| 3-Indoleacetic acid | 0.63 | 0.005 | Tryptophan metabolite |
| β-Sitosterol | 1.49 | 0.01 | Dietary phytosterol |
| Methyl stearateb | 1.50 | 0.01 | Fatty acid methyl ester |
| Lauric acid | 1.36 | 0.02 | Medium-chain fatty acid |
| Sucrose and similar disaccharides | 2.07 | 0.02 | Simple sugars |
| Methyl palmitateb | 1.38 | 0.02 | Fatty acid methyl ester |
| Methyl oleateb | 1.67 | 0.02 | Fatty acid methyl ester |
| Methyl linolenateb | 1.60 | 0.02 | Fatty acid methyl ester |
| Glycerol 1-phosphate | 1.86 | 0.04 | Glycolysis intermediate |
| Decanoic acid | 1.79 | 0.05 | Median-chain fatty acid |
| Malic acid | 1.46 | 0.05 | Intermediate of TCA cycle |
| Nonanoic acid | 1.46 | 0.06 | Median-chain fatty acid |
| Maltose or similar disaccharide | 1.79 | 0.06 | Simple sugar |
| Citric acid/isocitric acid | 1.40 | 0.07 | Intermediate of TCA cycle |
| Glycerol | 1.33 | 0.08 | Backbone of triglyceride |
| Urea | 1.40 | 0.08 | End product of protein metabolism |
| α-Ketoglutaric acid | 1.27 | 0.09 | Intermediate of TCA cycle |
| p-Cresol | 0.67 | 0.09 | Phenol derived from bacterial metabolism |
| Dehydroascorbic acid | 1.25 | 0.09 | Oxidized vitamin C |
| 2-Hydroxybutyric acid | 1.35 | 0.09 | α-Hydroxy fatty acid |
| Urine metabolites | |||
| Citric acid/isocitric acid | 2.71 | <0.001 | Intermediate of TCA cycle |
| Succinic acid | 2.01 | 0.002 | Intermediate of TCA cycle |
| 3-Indoleacetic acid | 2.01 | 0.005 | Tryptophan metabolite |
| 2-Ethyl-3-hydroxypropionic acid | 1.42 | 0.01 | β-Hydroxy fatty acid; related to BCAA metabolism |
| Methylmalonic acid | 1.45 | 0.02 | Dicarboxylic acid; anaplerotic substrate |
| Pimelic acid | 0.71 | 0.02 | Dicarboxylic acid |
| Glyoxylic acid | 0.57 | 0.02 | Carboxylic acid |
| α-Ketoglutaric acid | 1.61 | 0.03 | Intermediate of TCA cycle |
| 3-Methyl-3-Hydroxyisobutanoic acid | 1.41 | 0.03 | β-Hydroxy fatty acid; increased in ketoacidosis |
| Fumaric acid | 1.44 | 0.04 | Intermediate of TCA cycle |
| 2-Isopropylmalic acid | 1.69 | 0.05 | α-Hydroxy dicarboxylic acid; elevated in ketoacidosis |
| Hippuric acid | 1.35 | 0.08 | Acyl-glycine |
| Lactic acid | 1.69 | 0.1 | α-Hydroxy acid |
TCA, tricarboxylic acid; BCAA, branched chain amino acid.
a
Reported metabolites are identifiable metabolites from nontargeted analyses with a nominal P value ≤0.1.
b
Plasma C12 hydrocarbon and aminomalonic acid, and urine 4-hydroxycyclohexanecarboxylic acid were removed as likely contaminants. Methyl esters may be artificially derived during the extraction protocol with methanol but are listed because they may represent change in the underlying fatty acid ester. Alternatively they may represent increased methylation reactions in the setting of higher plasma pH.