Van Boom, Kathryn MerleKohn, Tertius AbrahamTordiffe, Adrian Stephen Wolferstan2026-02-192026-02-192025-04-23Van Boom, K., Kohn, T.A. & Tordiffe, A.S.W. 2025, 'Methionine, threonine and glutamic acid adapted pathways in captive cheetahs on a glycine-supplemented diet', Metabolomics, vol. 21, no. 3, art. 56, pp. 1-17. https://doi.org/10.1007/s11306-025-02243-1.1573-3882 (print)1573-3890 (online)h10.1007/s11306-025-02243-1http://hdl.handle.net/2263/108467DATA AVAILABILITY STATEMENT : Data is provided within the manuscript or supplementary information files. Metabolomics and metadata reported in this paper are also available via: UP’s Research Data Repository (Figshare). Study identifier: 10.25403/UPresearchdata.24494851. The corresponding author may be contacted for further requests.BACKGROUND : Captive cheetahs are prone to a range of unusual diseases potentially linked to unnatural diets high in muscle meat and low in collagen-rich animal fibre. In the wild, cheetahs typically eat whole prey diets not easily replicated in a captive setting. Glycine is the most abundant amino acid in collagen with a key role in several metabolic pathways such as collagen biosynthesis. Several recent studies suggest that endogenous glycine production may be limited in several species. OBJECTIVES : Using untargeted 1H- nuclear magnetic resonance, the metabolic changes in the urine and serum of 10 adult captive cheetahs on a glycine-supplemented diet were investigated. METHODS : Cheetahs were fed either a meat only (control) or glycine-supplemented meat diet (30 g glycine per 1 kg meat) for four weeks, followed by a four-week cross-over. Urine and blood samples were collected at baseline and after each intervention. RESULTS : A total of 151 and 60 metabolites were identified in the urine and serum, respectively. Specifically, dimethylsulphone, proline, fructose, dimethylamine, trimethylamine, pyroglutamic acid, 1,3-diaminopropane, dihydrothymine, methylmalonic acid and pimelic acid contributed to metabolome differences in the urine. In serum, glutamic acid, threonine, α-aminobutyric acid, glucose-6-phosphate, ethanolamine, methionine and propionic acid were highlighted. These metabolites play various metabolic roles in energy production, immune function, protein and collagen biosynthesis or as products of gut microbiome fermentation. CONCLUSION : Glycine supplementation influenced threonine sparing, pyrimidine biosynthesis pathways and bacterial fermentation products, although the implications of these findings on the health of captive cheetahs is unknown. Future studies should use a targeted approach to further elaborate on these pathways.en© 2025 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND).Acinonyx jubatusAmino acidsCheetah (Acinonyx jubatus)MetabolomicsNuclear magnetic resonance (NMR)NutritionArticle