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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.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Objectives<\/jats:title>\n            <jats:p>Using untargeted <jats:sup>1<\/jats:sup>H- nuclear magnetic resonance, the metabolic changes in the urine and serum of 10 adult captive cheetahs on a glycine-supplemented diet were investigated.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>Cheetahs were fed either a meat only (control) or glycine-supplemented meat diet (30\u00a0g glycine per 1\u00a0kg meat) for four weeks, followed by a four-week cross-over. Urine and blood samples were collected at baseline and after each intervention.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>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, \u03b1-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.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusion<\/jats:title>\n            <jats:p>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.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1007\/s11306-025-02243-1","type":"journal-article","created":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T02:21:03Z","timestamp":1745374863000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Methionine, threonine and glutamic acid adapted pathways in captive cheetahs on a glycine-supplemented diet"],"prefix":"10.1007","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1483-9061","authenticated-orcid":false,"given":"Kathryn M.","family":"van Boom","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4152-6319","authenticated-orcid":false,"given":"Tertius A.","family":"Kohn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5416-3153","authenticated-orcid":false,"given":"Adrian S. 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