Untargeted Metabolomics Reveals Key Differences Between Yak, Buffalo, and Cow Colostrum Based on UHPLC-ESI-MS/MS

Abstract

Background: Colostrum, abundant in immunoglobulins and growth factors, plays a vital role in supporting immunity. Both yak and buffalo milk are characterized by their high protein and fat content. However, the metabolomic profiles of yak colostrum (YC), buffalo colostrum (BC), and bovine colostrum (CC) remain largely unexplored. The objective of this study is to identify unique metabolites that may impact the nutritional value of colostrum.

Methods: This study employed ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) for untargeted metabolomics analysis of YC, BC, and CC.

Results: The analysis revealed 97, 70, and 75 differentially expressed metabolites in the YC-CC, BC-CC, and YC-BC comparisons, respectively. In comparison to CC, both YC and BC shared common features, including reduced choline levels and elevated O-acetylcarnitine. Moreover, metabolites such as 2-hydroxy-6-pentadecylbenzoic acid, DL-glycerol-1-phosphate, thiamine, L-carnitine, methyl β-D-galactoside, and uridine diphosphate (UDP) were identified as potential biomarkers for YC, while 21-deoxycortisol, D-synephrine, uridine, mannitol-1-phosphate, nonadecanoic acid, and perillic acid were specific to BC.

Conclusions: YC has greater advantages in energy supply, antioxidant activity, immune regulation, and cell homeostasis, and BC holds unique significance in physical development and energy balance regulation. These findings provide valuable insights, enabling the selection of unique bioactive metabolites to develop targeted functional foods from colostrum, catering to diverse nutritional needs.

Keywords: buffalo colostrum; colostrum biomarkers; cow colostrum; specific milk composition; untargeted metabolomics; yak colostrum.

Figure 1

Multivariate analysis of yak colostrum (YC), buffalo colostrum (BC), and cow colostrum (CC). (A,B) Principal component analysis (PCA) score plots in positive and negative ion modes, respectively. (C,D) Orthogonal partial least squares discriminant analysis (OPLS-DA) score plots in positive and negative ion modes, respectively. (E,F) OPLS-DA permutation test plots in positive and negative ion modes, respectively. (G,H) Correlation heatmaps of samples in positive and negative ion modes, respectively. *** p < 0.001.

Figure 2

Pairwise analysis of yak colostrum (YC), buffalo colostrum (BC), and cow colostrum (CC). (A) Volcano plot of differentially expressed metabolites (DEMs) between YC and CC. (B) Subclass composition of DEMs between YC and CC. (C) KEGG enrichment analysis presented as a mulberry map and bubble map for DEMs between YC and CC. (D) Volcano plot of DEMs between BC and CC. (E) Subclass composition of DEMs between BC and CC. (F) KEGG enrichment analysis as a mulberry map and bubble map for DEMs between BC and CC. (G) Volcano plot of DEMs between YC and BC. (H) Subclass composition of DEMs between YC and BC. (I) KEGG enrichment analysis in mulberry and bubble maps for DEMs between YC and BC.

Figure 3

Clustering and distribution of all differentially expressed metabolites (DEMs) from pairwise analysis of yak colostrum (YC), buffalo colostrum (BC), and cow colostrum (CC). (A) Heatmap showing all DEMs across YC, BC, and CC. (B) Upset plot displaying the overlap and unique DEMs among YC, BC, and CC.

Figure 4

Metabolite markers of yak colostrum (YC). (A) Z-score map of differentially expressed metabolites (DEMs) with higher expression in YC compared to BC and CC. (B) Relative content of 2-hydroxy-6-pentadecylbenzoic acid, DL-glycerol-1-phosphate, thiamine, L-carnitine, methyl β-D-galactoside, and uridine diphosphate (UDP) across YC, BC, and CC. (C) Receiver operating characteristic (ROC) curves for 2-hydroxy-6-pentadecylbenzoic acid, DL-glycerol-1-phosphate, thiamine, L-carnitine, methyl β-D-galactoside, and UDP. (D) KEGG pathway enrichment analysis of DEMs with differential expression in YC compared to BC and CC.

Figure 5

Metabolite markers of buffalo colostrum (BC). (A) Z-score map of differentially expressed metabolites (DEMs) with higher expression in BC compared to YC and CC. (B) Relative content of 21-deoxycortisol, D-synephrine, uridine, mannitol-1-phosphate, nonadecanoic acid, and perillic acid across YC, BC, and CC. (C) The receiver operating characteristic (ROC) curves for 21-deoxycortisol, D-synephrine, uridine, mannitol-1-phosphate, nonadecanoic acid, and perillic acid. (D) KEGG pathway enrichment analysis of DEMs with differential expression in BC compared to YC and CC.