Table 3.
CRC related metabolite biomarkers identified in 3 or more studies. Summarized metabolite was found increased or decreased in CRC vs. control in each paper, respectively. Reference numbers of studies in which a particular metabolite was identified are contained in parentheses after number of studies demonstrating increase or decrease. Consensus direction is reported in the final column, depicting the most commonly identified direction of regulation of each particular metabolite across reviewed studies.
| Metabolite | Times Identified | Studies Showing Upregulation | Studies Showing Downregulation | Studies Not Reporting Regulation Directionality | Consensus Direction |
|---|---|---|---|---|---|
| 3-hydroxybutarate | 4 | 3 (48, 35, 55) | 1 (52) | ↑ | |
| Alanine | 10 | 4 (53, 54, 22, 42) | 6 (48, 36, 46, 35, 28, 52) | ↓ | |
| Asparagine | 6 | 1 (24) | 5 (36, 46, 35, 28, 44) | ↓ | |
| Aspartic Acid | 5 | 1 (40) | 4 (48, 35, 55, 38) | ↓ | |
| Choline | 3 | 1 (48) | 2 (49, 28) | ↓ | |
| Citrulline | 5 | 2 (51, 56) | 3 (23, 36, 45) | ↓ | |
| Creatinine | 3 | 1 (35) | 2 (28, 33) | ↓ | |
| Cystine | 5 | 3 (35, 51, 40) | 1 (53) | 1 (56) | ↑ |
| Deoxycholate | 3 | 1 (31) | 2 (38, 44) | ↓ | |
| Glucose | 4 | 3 (48, 27, 43) | 1 (38) | ↑ | |
| Glutamic Acid/Glutamate | 8 | 7 (24, 48, 36, 22, 38, 40, 41) | 1 (35) | ↑ | |
| Glutamine | 4 | 1 (28) | 3 (48, 36, 42) | ↓ | |
| Glycerol | 5 | 4 (53, 48, 22, 39) | 1 (35) | ↑ | |
| Glycine | 7 | 6 (53, 48, 22, 28, 56) | 1 (43) | ↑ | |
| Hippurate/Hippuric Acid | 3 | 2 (49, 52) | 1 (28) | ↑ | |
| Histidine | 8 | 8 (23, 36, 35, 55, 33, 52, 44, 43) | ↑ | ||
| Isoleucine | 6 | 6 (53, 48, 54, 27, 56, 47) | ↑ | ||
| Kynurenine | 5 | 4 (30, 51, 56, 40) | 1 (36) | ↑ | |
| Lactate | 3 | 2 (48, 41) | 1 (56) | ↑ | |
| Leucine | 5 | 4 (48, 54, 22, 56) | 1 (36) | ↑ | |
| Linoleic Acid | 5 | 3 (53, 35, 25) | 2 (22, 45) | ↑ | |
| Lysine | 6 | 4 (53, 48, 54, 22) | 2 (36, 55) | ↑ | |
| LysoPC 16:0 | 3 | 3 (23, 49, 36) | ↓ | ||
| LysoPC 16:1 | 3 | 3 (49, 36, 35) | ↓ | ||
| LysoPC 17:0 | 3 | 3 (24, 49, 36) | ↓ | ||
| Methionine | 4 | 1 (47) | 3 (36, 35, 52) | ↓ | |
| Palmitic Acid | 5 | 5 (53, 31, 54, 35, 43) | ↑ | ||
| Phenylalanine | 7 | 3 (53, 56, 42) | 4 (36, 35, 33, 56) | ↓ | |
| Proline | 6 | 4 (49, 38, 42, 47) | 2 (48, 36) | ↑ | |
| Serine | 4 | 2 (48, 22) | 1 (35) | 1 (56) | ↑ |
| Sphinganine | 3 | 3 (31, 32, 35) | ↑ | ||
| Succinate | 3 | 2 (54, 56) | 1 (48) | ↑ | |
| Tryptophan | 5 | 1 (43) | 4 (36, 55, 28, 27) | ↓ | |
| Tyrosine | 9 | 3 (53, 43, 47) | 6 (48, 36, 46, 28, 56, 38) | ↓ | |
| Urea | 3 | 1 (38) | 2 (35, 27) | ↓ | |
| Valine | 7 | 3 (22, 56, 47) | 4 (48, 49, 36, 46) | ↓ |