TABLE 1.

Identified serum metabolites discriminant for the postprandial response after milk or yogurt intake in healthy men¹

Retention time (min)_Adduct mass (Da/charge)	Measured neutral mass (Da)	Identification	PubChem CID	Adducts	Identification method2	Product with the highest content	Product causing the highest postprandial response	Postprandial kinetic cluster	Product causing the highest fasting serum concentration after 2 wk of daily intake
1.11_219.0470	196.0578	Gluconic acid	10,690	.+H; +Na	1,2,4	Milk*	Milk*	4	Milk*
1.11_179.0550	178.0478	Δ-Gluconolactone	736	.+H	1,4	Milk*	Milk*	4	Milk*
1.16_138.0528	115.0636	Proline	145,742	.+H; .+Na; +2Na-H; .x2+H; .x2+Na	1,4	Milk*	Yogurt*	1	Yogurt
0.92_147.1123	146.1051	Lysine	5962	.+H; .+Na; .+2Na-H; .+H-H2O	1,4	Yogurt*	Yogurt*	2	Yogurt
1.06_164.0290	119.0578	Threonine	6288	.+H; .+2Na-H; .+Na	1,4	Milk	Yogurt*	2	Yogurt
3.43_166.0861	165.0789	Phenylalanine	6140	.+H; .x2+H	1,4	Yogurt*	Yogurt*	2	Milk
1.28_174.0868	132.0534	Asparagine	6267	.+ACN+H; .+Na; .+H-H2O	1,4	nd	Yogurt*	4	Milk
2.31_182.0807	181.0734	Tyrosine	6057	.+H; .+Na	1,4	Yogurt*	Yogurt*	2	Milk
4.23_205.0972	204.0899	Tryptophan	6305	.+H; .+Na	1,2,3,4	Yogurt*	Yogurt	—	Milk
1.07_198.0846	175.0954	Citrulline	9750	.+H; .+Na; +2Na-H	1,4	nd	Yogurt*	1	Yogurt
1.07_126.0214	125.0142	Taurine	1123	.+H; +2Na-H; .+Na; .+H-H2O	1,4	Yogurt	Milk*	4	Milk
6.04_206.0807	205.0735	Indole-3-lactic acid	92,904	.+H; .+Na	1,2,3,4	Yogurt*	Yogurt*	1	Yogurt
6.04_160.0753	159.0680	Indole-3-acetaldehyde	800	.+H	1,2	Yogurt*	Yogurt*	1	Yogurt
6.67_176.0701	175.0629	Indole-3-acetic acid	802	.+H; .+Na	1,2,3,4	nd	Milk*	5	Milk
7.26_190.0858	189.0785	3-Indole propionic acid	3744	.+H; .+Na; .+H+H2O	1,2,4	nd	Milk*	4	Milk*
9.91_375.2887	374.2814	3b-Hydroxy-5-cholenoic acid	92,997	.+H; .+H-H2O; .+H-2H2O	1,2,3,4	nd	Milk*	5	Yogurt
10.10_434.3256	392.2920	(cheno)Deoxycholic acid	222,528	.+H; .+Na; .+NH4; .+H-H2O; .+H-2H2O; .x2+H	1,2,3,4	nd	Milk*	5	Yogurt
8.46_450.3205	449.3132	Glycoursodeoxycholic acid	12,310,288	.+H; .+NH4; .+Na; .x2+H; .x2+Na; .x2+NH4; .+H-H2O; .+H-2H2O	1,2	nd	Milk*	5	Milk
7.40_483.3415	465.3077	Glycocholic acid	10,140	.+H; .+NH4; .+Na; .+H-H2O; .+H-2H2O	1,2,4	nd	Milk*	5	Yogurt
9.51_500.3028	499.2956	Tauroursodeoxycholic acid	9,848,818	.+H; .+H-H2O; .+H-2H2O	1,2,3,4	nd	Milk*	5	Milk

¹*OPLS-DA VIP_tot score > 1 or P < 0.05. CID, compound identifier; nd, not detected; OPLS-DA, orthogonal projections to latent structures discriminant analysis; VIP_tot, variable importance in projection for the predictive and orthogonal components.

²Identification methods: 1, mass database; 2, theoretical fragmentation; 3, fragment database; 4, standard injection.