{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T16:21:48Z","timestamp":1772900508727,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,2,20]],"date-time":"2023-02-20T00:00:00Z","timestamp":1676851200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"High-Value Nutrition National Science Challenge","award":["UOAX1902"],"award-info":[{"award-number":["UOAX1902"]}]},{"DOI":"10.13039\/501100003524","name":"New Zealand Ministry of Business, Innovation, and Employment (MBIE)","doi-asserted-by":"publisher","award":["UOAX1902"],"award-info":[{"award-number":["UOAX1902"]}],"id":[{"id":"10.13039\/501100003524","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Amino acids are important in several biochemical pathways as precursors to neurotransmitters which impact biological processes previously linked to functional gastrointestinal disorders (FGIDs). Dietary protein consumption, metabolic host processes, and the gut microbiome can influence the plasma concentration of amino acids and neurotransmitters, and their uptake by tissues. The aim of this analysis was to quantify 19 proteogenic and 4 non-proteogenic amino acids and 19 neurotransmitters (including precursors and catabolites, herein referred to as neurotransmitters) to ascertain if their circulating concentrations differed between healthy participants and those with FGIDs. Plasma proteogenic and non-proteogenic amino acids and neurotransmitters were measured using ultra-performance liquid chromatography and liquid chromatography\u2013mass spectrometry, respectively, from 165 participants (Rome IV: irritable bowel syndrome (IBS-constipation, IBS-diarrhea), functional constipation, functional diarrhea, and healthy controls). There were significant differences (p &lt; 0.05) in pairwise comparisons between healthy controls and specific FGID groups for branched-chain amino acids (BCAAs), ornithine, and alpha-aminobutyric acid. No other significant differences were observed for the neurotransmitters or any other amino acids analyzed. Multivariate and bivariate correlation analyses between proteogenic and non-proteogenic amino acids and neurotransmitters for constipation (constipation (IBS-C and functional constipation) and phenotypes diarrhea (IBS-D and functional diarrhea)) and healthy controls suggested that associations between BCAAs, 5-hydroxytryptophan, and kynurenine in combination with tyrosine, 3,4-dihydroxyphenylalanine, and 3,4-dihydroxyphenylacetic acid and associations with gamma-aminobutyric acid, glutamate, asparagine, and serine are likely disrupted in FGID phenotypes. In conclusion, although correlations were evident between some proteogenic and non-proteogenic amino acids and neurotransmitters, the results showed minor concentration differences in plasma proteogenic and non-proteogenic amino acids, amino acid-derived metabolites, and neurotransmitters between FGID phenotypes and healthy controls.<\/jats:p>","DOI":"10.3390\/metabo13020313","type":"journal-article","created":{"date-parts":[[2023,2,21]],"date-time":"2023-02-21T02:07:44Z","timestamp":1676945264000},"page":"313","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Concentrations of Plasma Amino Acids and Neurotransmitters in Participants with Functional Gut Disorders and Healthy Controls"],"prefix":"10.3390","volume":"13","author":[{"given":"Shanalee C.","family":"James","sequence":"first","affiliation":[{"name":"The Riddet Institute, Massey University, 4474 Palmerston North, New Zealand"},{"name":"School of Food and Advanced Technology, Massey University, 4472 Palmerston North, New Zealand"},{"name":"AgResearch, Tennent Drive, 4442 Palmerston North, New Zealand"},{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1136-4024","authenticated-orcid":false,"given":"Karl","family":"Fraser","sequence":"additional","affiliation":[{"name":"The Riddet Institute, Massey University, 4474 Palmerston North, New Zealand"},{"name":"AgResearch, Tennent Drive, 4442 Palmerston North, New Zealand"},{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2547-0100","authenticated-orcid":false,"given":"Janine","family":"Cooney","sequence":"additional","affiliation":[{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"The New Zealand Institute for Plant and Food Research Ltd., Ruakura Campus, Bisley Road, 3214 Hamilton, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9712-0169","authenticated-orcid":false,"given":"Catrin S.","family":"G\u00fcnther","sequence":"additional","affiliation":[{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"The New Zealand Institute for Plant and Food Research Ltd., Ruakura Campus, Bisley Road, 3214 Hamilton, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wayne","family":"Young","sequence":"additional","affiliation":[{"name":"The Riddet Institute, Massey University, 4474 Palmerston North, New Zealand"},{"name":"AgResearch, Tennent Drive, 4442 Palmerston North, New Zealand"},{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Richard B.","family":"Gearry","sequence":"additional","affiliation":[{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"Department of Medicine, University of Otago, 8011 Christchurch, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phoebe E.","family":"Heenan","sequence":"additional","affiliation":[{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"Department of Medicine, University of Otago, 8011 Christchurch, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tania","family":"Trower","sequence":"additional","affiliation":[{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"The New Zealand Institute for Plant and Food Research Ltd., Ruakura Campus, Bisley Road, 3214 Hamilton, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jacqueline I.","family":"Keenan","sequence":"additional","affiliation":[{"name":"Department of Surgery, University of Otago, 8011 Christchurch, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2537-3092","authenticated-orcid":false,"given":"Nicholas J.","family":"Talley","sequence":"additional","affiliation":[{"name":"School of Medicine and Public Health, The University of Newcastle, Callaghan, Newcastle 2308, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2514-6551","authenticated-orcid":false,"given":"Warren C.","family":"McNabb","sequence":"additional","affiliation":[{"name":"The Riddet Institute, Massey University, 4474 Palmerston North, New Zealand"},{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6744-9705","authenticated-orcid":false,"given":"Nicole C.","family":"Roy","sequence":"additional","affiliation":[{"name":"The Riddet Institute, Massey University, 4474 Palmerston North, New Zealand"},{"name":"High-Value Nutrition National Science Challenge, 1023 Auckland, New Zealand"},{"name":"Department of Human Nutrition, University of Otago, 9016 Dunedin, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"97","DOI":"10.4292\/wjgpt.v4.i4.97","article-title":"Metabolomics as a Diagnostic Tool in Gastroenterology","volume":"4","author":"Verbeke","year":"2013","journal-title":"World J. 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