Data Sheet 2_Plasma metabolomics reveals metabolic signatures associated with Lactobacillus reuteri supplementation in ewes.pdf

Among 1,003 metabolites detected, 27 were differentially abundant (P < 0.05); 9 were elevated in LR, including cyanamide, aspartic acid, L-homoserine, 1-pyrroline-4-hydroxy-2-carboxylic acid, and 3-hydroxypicolinic acid, while 18 were elevated in CON, including 9-oxononanoic acid, isomer 2 of sebacic acid, hydroxylated lecithin, L-fucose, tyramine, and nocardicin A/isonocardicin A. Pathway analysis identified cysteine and methionine metabolism, tryptophan metabolism, primary bile acid biosynthesis, and lysine degradation as enriched in LR ewes (P < 0.05, topology impact > 0.10).

Biomarker analyses identified six metabolites, cyanamide, β-alanine, L-ornithine/D-ornithine, hydroxylated lecithin, 9-oxononanoic acid, and isomer 2 of sebacic acid, with sufficient sensitivity and specificity (P < 0.05, Area Under the Curve (AUC) > 0.87) to serve as putative biomarkers of LR supplementation. Plasma cyanamide correlated positively (ρ = 0.67, P < 0.01) and hydroxylated lecithin negatively (ρ = -0.75, P < 0.001) with average daily gain, with hydroxylated lecithin also linked to feed: gain (ρ = 0.68, P < 0.01), identifying it as the strongest single biomarker of the growth and feed efficiency phenotype.

The broad metabolite depletion in LR ewes is consistent with enhanced peripheral substrate utilization, indicating that these findings suggest that LR supplementation may improve performance through alterations in amino acid, redox, and immunomodulatory pathways. Validation in larger, multi-breed cohorts is warranted.</p>