# Serum Metabolomics Uncovers Immune and Lipid Pathway Alterations in Lambs Supplemented with Novel LAB-Bifidobacterium Cocktail

## TL;DR

A new probiotic mix of LAB and Bifidobacterium changed lamb metabolism, affecting lipids and immune-related pathways, offering a potential alternative to antibiotics.

## Contribution

A novel multi-strain LAB-Bifidobacterium cocktail was tested for its metabolic impact in lambs using untargeted metabolomics.

## Key findings

- Probiotic supplementation altered lipid and amino acid metabolism in lambs, with 38 upregulated metabolites by day 15.
- Key metabolites like cholesterol, arachidonic acid, and D-glucose increased significantly by day 30 in the probiotic group.
- Multivariate analyses confirmed distinct metabolic profiles and identified strong predictive biomarkers for the probiotic effect.

## Abstract

The ban on antibiotic growth promoters in livestock has intensified the search for effective probiotic alternatives. This study assessed the impact of a novel probiotic cocktail—comprising Lactobacillus plantarum AMT14 and AMT4, L. rhamnosus AMT15, and Bifidobacterium animalis AMT30—on the serum metabolome of lambs using an untargeted GC/MS approach. Sixteen Kamieniec lambs were divided into control and probiotic groups, with serum collected on days 0, 15, and 30. Metabolomic profiling revealed significant alterations in lipid and amino acid metabolism in the probiotic group. By day 15, 38 metabolites were upregulated, including 9,12-octadecadienoic acid, arachidonic acid, and cholesterol. On day 30, key increases included D-glucose, oleic acid, glycine, decanoic acid, and L-leucine. Multivariate analyses (PCA, PLS-DA) demonstrated clear separation between groups, and ROC analysis identified strong biomarkers with high predictive accuracy. These results suggest that probiotic supplementation can beneficially modulate host metabolism, potentially enhancing immune and physiological function in lambs. This highlights the value of multi-strain LAB-Bifidobacterium probiotics as a promising strategy for improving health and reducing antibiotic reliance in ruminant production systems.