Summary of metabolic changes in urinary (u) and faecal (f) NMR profiles
| Class | Metabolites | O-PLS-DA models of RYGB-operated and sham control rats | |||
| 2-week post-op | 4-week post-op | 6-week post-op | 8-week post-op | ||
| TCA cycle | Succinate | −0.6977(u) | −0.6591(u); +0.5879(f) | −0.8562(u) | −0.7674(u); +0.6286(f) |
| 2-Oxoglutarate | −0.6509(u) | −0.6333(u); *+0.6170(u) | −0.8084(u) | −0.8153(u) | |
| Citrate | −0.6090(u) | −0.4856(u) | −0.6150(u) | −0.5045(u) | |
| Fumarate | −0.6518(u) | −0.6374(u); | −0.8703(u) | −0.7200(u) | |
| Amines | Trimethylamine N-oxide | +0.5183(u); *+0.7718(u) | +0.5755(u); *+0.6994(u) | +0.6311(u); *+0.6241(u) | +0.6937(u); *+0.7320(u) |
| Trimethylamine | +0.6016(f) | +0.8156(f) | +0.6865(f) | ||
| Methylamine | +0.5196(f) | +0.7819(f) | +0.6933(f) | +0.7167(f) | |
| Putrescine | +0.6133(f) | +0.6601(f) | +0.7048(f) | +0.7328(f) | |
| Diaminoethane | +0.5170(f) | +0.6573(f) | +0.7230(f) | ||
| Microbial activity | Oligosaccharides | −0.6144(f) | −0.6461(f) | ||
| Acetate | +0.5415(f) | +0.5413(f) | |||
| Propionate | +0.5916(f) | +0.5186(f) | |||
| p-Cresol glucuronide | +0.7785(u) | +0.6304(u) | +0.7116(u) | +0.7225(u); *+0.6367(u) | |
| p-Cresol sulphate | +0.7980(u) | +0.6911(u) | +0.6501(u) | +0.7303(u) | |
| 5-Aminovalerate | +0.6977(u) | +0.5518(u) | +0.6297(u) | +0.6921(u) | |
| Phenylacetylglycine | +0.9192(u); *+0.5416(u) | +0.7038(u) | +0.8432(u); *+0.5497(u) | +0.7533(u) | |
| p-Hydroxyphenylacetate | +0.7129(u) | +0.5207(u) | +0.6546(u) | +0.6176(u) | |
| Hippurate | −0.8768(u) | −0.6692(u) | |||
| Methanol | +0.5561(f) | +0.5167(f) | |||
| Formate | +0.6820(f) | +0.5907(f) | |||
| Tyrosine | −0.6139(f) | −0.6726(f) | −0.6543(f); *+0.5820(f) | −0.6065(f) | |
| Peripheral neuroactive intermediate | γ-Amino-N-butyrate | +0.7036(f) | +0.7373(f) | +0.7038(f) | +0.6806(f) |
| Glutamate | +0.5514(f) | +0.5914(f) | |||
| Urea cycle | Aspartate | −0.6653(f) | −0.7314(f) | −0.6881(f) | −0.6999(f) |
| Muscle metabolism | Creatine | +0.6619 (u) | +0.4473(u) | +0.7781(u) | +0.7294(u) |
| Creatinine | *+0.6337(u) | −0.7473(u); *+0.6424(u) | |||
| Lactate | +0.5871(f) | ||||
| Renal metabolism | Indoxyl sulphate | +0.8598(u) | +0.7271(u) | +0.6550(u); *+0.7770(u) | +0.6542(u) |
| Amino acids | Valine | +0.5822(f) | |||
| Phenylalanine | +0.5849(f); *+0.5719(f) | ||||
| Alanine | *+0.5636(f) | ||||
| Glycine | +0.6577(f) | +0.6317(f) | +0.5698(f); *+0.6521(f) | +0.5377(f) | |
| Others | N-Acetyl glycoproteins 2.06(s)† | −0.7523(f) | −0.6160(f); *−0.5648(f) | ||
| Ethanol | +0.6365(f) | +0.6904(f) | |||
| Phenylalanine | +0.5849(f); *+0.5719(f) | ||||
| 2-Oxoadipate | −0.8260(u) | −0.6238(u) | −0.9030(u) | −0.9045(u) | |
‘+’ indicates a higher concentration of metabolites in RYGB-operated rats; ‘–’ indicates a lower concentration of metabolites in RYGB-operated rats.
↵* Labelled metabolites are found to be changed in sham control rats in comparison with pre-operation, where ‘+’/‘–’ indicates higher/lower concentrations of metabolites post-sham.
↵† Putative assignment.
The numbers are the coefficient values. NMR, nuclear magnetic resonance; RYGB, Roux-en-Y gastric bypass; TCA, tricarboxylic acid.