Table 4. The VIP score and fold change of metabolites significantly differentially expressed between exclusive and partial breastfeeding at different years of age.

		Age 0.5				Age 1			Age 2			Age 3
Metabolites	Chemical shift	VIP score		Fold change	P	VIP score	Fold change	P	VIP score	Fold change	P	VIP score	Fold change	P
Creatine	3.935(s)		6.86	0.55	0.010	6.97	0.76	0.038	1.96	1.08	0.827	3.90	0.88	0.679
Glycine	3.575–3.565(s)		4.66	1.28	0.013	5.16	1.30	0.016	5.42	0.79	0.090	3.01	0.88	0.254
Fucose	1.265–1.246(d)		3.65	1.49	0.004	2.31	1.16	0.025	-	1.01	0.827	-	0.96	0.953
Glutamine	2.465–2.425(m)		3.45	1.17	0.022	-	1.03	0.824	-	1.01	0.510	-	1.00	1.000
Hippuric acid	7.575–7.545(n)		3.41	0.49	0.006	3.32	0.61	0.004	4.24	1.52	0.320	5.31	0.58	0.859
Lysine	1.915–1.865(m)		2.74	0.87	0.017	-	0.99	1.000	2.27	0.92	0.221	-	0.99	1.000
N-Acetylglucosamine	2.055–2.045(m)		2.73	1.14	0.028	3.46	1.17	0.025	-	1.01	0.913	-	0.95	0.953
Methylmalonic acid	1.235–1.226(d)		2.45	1.30	0.022	-	1.08	0.295	-	0.93	0.510	1.98	0.89	0.310
Carnitine	3.235–3.225(s)		2.20	0.81	0.028	3.28	0.79	0.067	-	1.10	0.743	-	0.98	0.440
3-Methyl-2-oxovaleric acid	1.115–1.106(d)		2.01	0.65	0.006	1.84	0.76	0.020	-	1.11	0.510	2.35	1.41	0.099
3-Hydroxyisovaleric acid	2.365(s)		1.78	1.23	0.006	-	1.12	0.131	-	0.97	0.827	-	0.96	0.594
Acetic acid	1.925(s)		3.68	1.75	0.079	7.44	2.69	0.020	3.37	0.80	0.267	-	1.06	1.000
Formic acid	8.465–8.455(s)		1.50	1.36	0.356	2.96	1.63	0.010	2.38	0.69	0.145	-	0.91	0.768
Galactose	5.285–5.276(d)		-	0.86	0.497	2.36	0.50	0.020	1.63	1.59	0.090	1.81	1.69	0.371
Pantothenic acid	0.895(s)		-	0.96	0.549	1.59	0.80	0.031	-	1.14	0.267	-	1.15	0.254
Hypoxanthine	8.215–8.196(s)		-	0.77	0.113	-	1.03	0.552	2.15	1.50	0.013	-	0.89	0.594
2-Phenylpropionic acid	1.415(d)		-	0.80	0.017	-	0.84	0.503	-	1.26	0.267	2.60	1.54	0.019

VIP, Variable Importance in Projection; s, singlet; d, doublet; m, multiplet; n, nonet.

VIP scores were obtained from PLS-DA model and a VIP score < 1.5 was shown as “-”.

Fold change was calculated by dividing the value of metabolites in children receiving exclusive breastfeeding by partial breastfeeding.

All P values < 0.05, which is in bold, are significant.