Table 1.
Comparison of milk metabolites concentrations (µmol/L) by country of origin.
| MEAN (SD) | |||||
|---|---|---|---|---|---|
| Metabolites/Countries | South Africa | Japan | Norway | US | Perth #2 |
| 2-Oxoglutarate | 79.6 (25.6) | 79.1 (49.2) ## | 30.5 (31.2) *** | 39.0 (12.7) * | 47.5 (19.9) |
| Acetone | 13.2 (6.4) | 19.8 (15.7) | 10.8 (7.6) | 11.4 (3.3) | 13.3 (7.5) |
| Alanine | 161.0 (93.5) | 233.6 (96.8) | 208.1 (84.5) | 240.1 (91.9) | 203.2 (48.4) |
| Betaine | 668.1 (201.8) | 355.3 (367.1) | 180.4 (318.8) *** | 408.4 (567.8) | 58.8 (6.6) *** |
| Caprate | 108.6 (124.7) | 193.1 (216.3) | 121.5 (120.3) | 60.0 (90.6) | 114.0 (42.9) |
| Caprylate | 157.1 (137.2) | 357.6 (497.0) | 131.6 (207.1) | 92.7 (132.5) | 82.7 (47.1) |
| Choline | 322.1 (194.9) | 192.0 (128.3) | 184.1 (163.7) | 133.0 (77.0) | 138.5 (71.1) |
| Citrate | 5614 (3920) | 2830 (1313) * | 2718 (1361) *** | 3642 (1272) | 2856 (836.1) * |
| Creatine | 274.7 (342.9) | 60.3 (28.4) * | 63.9 (26.9) *** | 56.8 (23.4) * | 66.5 (19.0) * |
| Creatine phosphate | 49.6 (54.3) | 45.2 (31.1) | 20.6 (13.1) * | 42.0 (12.7) | 23.9 (7.6) |
| Creatinine | 108.8 (82.7) | 42.9 (15.4) ** | 43.7 (15.6) *** | 57.3 (22.9) * | 45.0 (5.7) ** |
| Formate | 83.4 (79.4) | 112.2 (127.8) | 902.0 (1695.2) | 91.9 (55.7) | 127.1 (24.9) |
| Fucose | 278.5 (373.5) | 570.9 (482.9) | 330.5 (252.5) | 344.4 (216.4) | 382.3 (277.5) |
| Glucose | 1347 (852.9) | 1563 (1327) | 926.4 (747.8) | 1697 (413.5) | 1699 (935.9) |
| Glutamate | 858.9 (491.3) | 1296 (565.8) | 1467 (835.2) | 1573 (830.2) | 1554 (369.4) |
| Glutamine | 282.0 (150.9) | 103.0 (88.1) | 101.9 (119.0) | 514.2 (618.2) ### | 207.6 (178.2) |
| Glycine | 2796 (759.9) | 3135 (1373) | 2512 (1191) | 1641 (1777) | 1919 (949.5) |
| Guanidoacetate | 4771 (1048) | 3777 (1747) | 3373 (2944) | 3435 (1770) | 1622 (286.5) * |
| Isoleucine | 20.8 (12.2) | 24.1 (25.9) | 24.2 (21.1) | 10.9 (2.6) | 12.0 (4.0) |
| Lactate | 213.7 (63.1) | 3215 (5561) **## | 443.5 (693.6) | 137.8 (102.0) | 125.7 (41.5) |
| Lactose | 189,874 (34,234) | 139,161 (83,333) | 101,351 (84,404) * | 161,160 (123,638) | 83,524 (23,509) * |
| Leucine | 33.7 (21.1) | 49.9 (61.2) | 66.2 (76.2) | 30.9 (8.9) | 34.0 (7.8) |
| Methanol | 78.0 (17.6) | 97.7 (49.2) ### | 46.1 (19.3) *** | 89.2 (6.7) ### | 72.0 (6.8) # |
| Phosphocholine | 636.9 (328.6) | 784.7 (470.6) | 463.7 (326.7) | 698.3 (231.2) | 488.4 (145.6) |
| Pyruvate | 53.3 (29.5) | 68.6 (69.8) ## | 20.0 (26.3) * | 31.7 (39.7) | 6.3 (2.5) * |
| Succinate | 48.3 (67.0) | 47.9 (25.9) | 210.8 (515.7) | 21.2 (9.6) | 49.3 (15.7) |
| Valine | 35.3 (11.9) | 63.9 (33.5) | 65.6 (32.7) * | 50.2 (21.1) | 57.4 (17.6) |
| Glycerophosphocholine | 797.6 (439.3) | 645.0 (393.0) | 414.9 (346.0) * | 589.2 (239.7) | 517.4 (118.5) |
| # metabolite differences with South Africa | na | 4 | 11 | 3 | 7 |
| # metabolite differences with Norway | - | 4 | na | 2 | 1 |
* p < 0.05, ** p < 0.01, *** p < 0.001 when reference = South Africa; # p < 0.05, ## p < 0.01, ### p < 0.001 when reference = Norway; na: not applicable.