{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T18:53:04Z","timestamp":1793213584538,"version":"4.5.0"},"reference-count":57,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2022,1,7]],"date-time":"2022-01-07T00:00:00Z","timestamp":1641513600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2022,1,7]],"date-time":"2022-01-07T00:00:00Z","timestamp":1641513600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100013342","name":"NIHR Imperial Biomedical Research Centre","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100013342","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000273","name":"Diabetes Research and Wellness Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000273","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000265","name":"Medical Research Council","doi-asserted-by":"publisher","award":["MC_PC_12025"],"award-info":[{"award-number":["MC_PC_12025"]}],"id":[{"id":"10.13039\/501100000265","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>This study aims to explore the immediate effects of bariatric surgery on serum tryptophan\u2013kynurenine pathway metabolites in individuals with type 2 diabetes and BMI\u2009&gt;\u200930. With the goal of providing insight into the link between tryptophan pathway metabolites, type 2 diabetes, and chronic obesity-induced inflammation. This longitudinal study included 20 participants. Half were diagnosed with type 2 diabetes. 11 and 9 underwent RYGB and SG respectively. Blood samples were obtained at pre-operative and 3 months post-operative timepoints. Tryptophan and downstream metabolites of the kynurenine pathway were quantified with an ultrahigh-performance liquid chromatography tandem mass spectrometry with electrospray ionisation method. At 3\u00a0months post-operation, RYGB led to significant reductions in tryptophan, kynurenic acid and xanthurenic acid levels when compared to baseline. Significant reductions of the same metabolites after surgery were also observed in individuals with T2D irrespective of surgical procedure. These metabolites were significantly correlated with serum HbA1c levels and BMI. Bariatric surgery, in particular RYGB reduces serum levels of tryptophan and its downstream kynurenine metabolites. These metabolites are associated with T2D and thought to be potentially mechanistic in the systemic processes of obesity induced inflammation leading to insulin resistance. Its reduction after surgery is associated with an improvement in glycaemic control (HbA1c).<\/jats:p>","DOI":"10.1038\/s41598-021-03833-4","type":"journal-article","created":{"date-parts":[[2022,1,7]],"date-time":"2022-01-07T06:03:21Z","timestamp":1641535401000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["The impact of bariatric surgery on serum tryptophan\u2013kynurenine pathway metabolites"],"prefix":"10.1038","volume":"12","author":[{"given":"Kai Tai Derek","family":"Yeung","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicholas","family":"Penney","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luke","family":"Whiley","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hutan","family":"Ashrafian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew R.","family":"Lewis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanjay","family":"Purkayastha","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ara","family":"Darzi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elaine","family":"Holmes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2022,1,7]]},"reference":[{"issue":"7","key":"3833_CR1","doi-asserted-by":"crossref","first-page":"641","DOI":"10.1056\/NEJMoa1600869","volume":"376","author":"PR Schauer","year":"2017","unstructured":"Schauer, P. R. et al. Bariatric surgery versus intensive medical therapy for diabetes\u20145-year outcomes. N. Engl. J. Med. 376(7), 641\u2013651 (2017).","journal-title":"N. Engl. J. Med."},{"issue":"2","key":"3833_CR2","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1007\/s00125-017-4513-y","volume":"61","author":"DE Cummings","year":"2018","unstructured":"Cummings, D. E. & Rubino, F. Metabolic surgery for the treatment of type 2 diabetes in obese individuals. Diabetologia 61(2), 257\u2013264 (2018).","journal-title":"Diabetologia"},{"issue":"7","key":"3833_CR3","doi-asserted-by":"crossref","first-page":"e1003206","DOI":"10.1371\/journal.pmed.1003206","volume":"17","author":"T Wiggins","year":"2020","unstructured":"Wiggins, T., Guidozzi, N., Welbourn, R., Ahmed, A. R. & Markar, S. R. Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: A systematic review and meta-analysis. PLoS Med. 17(7), e1003206 (2020).","journal-title":"PLoS Med."},{"issue":"12","key":"3833_CR4","doi-asserted-by":"crossref","first-page":"912","DOI":"10.1016\/S2213-8587(19)30344-4","volume":"7","author":"D Hofs\u00f8","year":"2019","unstructured":"Hofs\u00f8, D. et al. Gastric bypass versus sleeve gastrectomy in patients with type 2 diabetes (Oseberg): A single-centre, triple-blind, randomised controlled trial. Lancet Diabetes Endocrinol. 7(12), 912\u2013924 (2019).","journal-title":"Lancet Diabetes Endocrinol."},{"issue":"5","key":"3833_CR5","doi-asserted-by":"crossref","first-page":"300","DOI":"10.7326\/M17-2383","volume":"169","author":"R O'Brien","year":"2018","unstructured":"O\u2019Brien, R. et al. Microvascular outcomes in patients with diabetes after bariatric surgery versus usual care: A matched cohort study. Ann. Intern. Med. 169(5), 300\u2013310 (2018).","journal-title":"Ann. Intern. Med."},{"issue":"6","key":"3833_CR6","doi-asserted-by":"crossref","first-page":"893","DOI":"10.2337\/dc16-0145","volume":"39","author":"RL Batterham","year":"2016","unstructured":"Batterham, R. L. & Cummings, D. E. Mechanisms of diabetes improvement following bariatric\/metabolic surgery. Diabetes Care 39(6), 893\u2013901 (2016).","journal-title":"Diabetes Care"},{"key":"3833_CR7","doi-asserted-by":"crossref","first-page":"530","DOI":"10.3389\/fendo.2018.00530","volume":"9","author":"B Laferr\u00e8re","year":"2018","unstructured":"Laferr\u00e8re, B. & Pattou, F. Weight-independent mechanisms of glucose control after Roux-en-Y gastric bypass. Front. Endocrinol. 9, 530 (2018).","journal-title":"Front. Endocrinol."},{"issue":"2","key":"3833_CR8","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1007\/s11695-019-04235-2","volume":"30","author":"AJ Sharples","year":"2020","unstructured":"Sharples, A. J. & Mahawar, K. Systematic review and meta-analysis of randomised controlled trials comparing long-term outcomes of Roux-En-Y gastric bypass and sleeve gastrectomy. Obes. Surg. 30(2), 664\u2013672 (2020).","journal-title":"Obes. Surg."},{"issue":"2","key":"3833_CR9","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1007\/s11695-018-3573-5","volume":"29","author":"Y Zhang","year":"2019","unstructured":"Zhang, Y. et al. Improvement in nocturnal hypoxemia in obese patients with obstructive sleep apnea after bariatric surgery: A meta-analysis. Obes. Surg. 29(2), 601\u2013608 (2019).","journal-title":"Obes. Surg."},{"key":"3833_CR10","doi-asserted-by":"crossref","first-page":"e200087","DOI":"10.1001\/jamasurg.2020.0087","volume":"155","author":"KM McTigue","year":"2020","unstructured":"McTigue, K. M. et al. Comparing the 5-year diabetes outcomes of sleeve gastrectomy and gastric bypass: The National Patient-Centered Clinical Research Network (PCORNet) bariatric study. JAMA Surg. 155, e200087 (2020).","journal-title":"JAMA Surg."},{"key":"3833_CR11","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.1016\/j.soard.2020.04.033","volume":"16","author":"V Wallenius","year":"2020","unstructured":"Wallenius, V. et al. Sleeve gastrectomy and Roux-en-Y gastric bypass in the treatment of type 2 diabetes. Two-year results from a Swedish multicenter randomized controlled trial. Surg. Obes. Relat. Dis. 16, 1035 (2020).","journal-title":"Surg. Obes. Relat. Dis."},{"issue":"2","key":"3833_CR12","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/j.soard.2019.11.013","volume":"16","author":"A Aminian","year":"2020","unstructured":"Aminian, A. Bariatric procedure selection in patients with type 2 diabetes: Choice between Roux-en-Y gastric bypass or sleeve gastrectomy. Surg. Obes. Relat. Dis. 16(2), 332\u2013339 (2020).","journal-title":"Surg. Obes. Relat. Dis."},{"issue":"4","key":"3833_CR13","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1038\/ni.3120","volume":"16","author":"FM Wensveen","year":"2015","unstructured":"Wensveen, F. M. et al. NK cells link obesity-induced adipose stress to inflammation and insulin resistance. Nat. Immunol. 16(4), 376\u2013385 (2015).","journal-title":"Nat. Immunol."},{"issue":"2","key":"3833_CR14","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1021\/acs.jproteome.6b00710","volume":"16","author":"MS Ahmad","year":"2017","unstructured":"Ahmad, M. S. et al. Metabolic phenotype of obesity in a Saudi population. J. Proteome Res. 16(2), 635\u2013644 (2017).","journal-title":"J. Proteome Res."},{"key":"3833_CR15","doi-asserted-by":"crossref","first-page":"557","DOI":"10.3389\/fimmu.2020.00557","volume":"11","author":"S Cussotto","year":"2020","unstructured":"Cussotto, S. et al. Tryptophan metabolic pathways are altered in obesity and are associated with systemic inflammation. Front. Immunol. 11, 557 (2020).","journal-title":"Front. Immunol."},{"key":"3833_CR16","doi-asserted-by":"crossref","first-page":"45","DOI":"10.4137\/IJTR.S2129","volume":"2","author":"DM Richard","year":"2009","unstructured":"Richard, D. M. et al. L-tryptophan: Basic metabolic functions, behavioral research and therapeutic indications. Int. J. Tryptophan. Res. 2, 45\u201360 (2009).","journal-title":"Int. J. Tryptophan. Res."},{"key":"3833_CR17","doi-asserted-by":"crossref","first-page":"6349","DOI":"10.1126\/science.aaf9794","volume":"357","author":"I Cervenka","year":"2017","unstructured":"Cervenka, I., Agudelo, L. Z. & Ruas, J. L. Kynurenines: Tryptophan\u2019s metabolites in exercise, inflammation, and mental health. Science (New York). 357, 6349 (2017).","journal-title":"Science (New York)."},{"key":"3833_CR18","doi-asserted-by":"publisher","DOI":"10.32527\/2019\/101415","author":"AA-B Badawy","year":"2019","unstructured":"Badawy, A.A.-B. Tryptophan metabolism: A versatile area providing multiple targets for pharmacological intervention. Egypt J. Basic Clin. Pharmacol. https:\/\/doi.org\/10.32527\/2019\/101415 (2019).","journal-title":"Egypt J. Basic Clin. Pharmacol."},{"key":"3833_CR19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1749-6632.2009.05356.x","volume":"1199","author":"GF Oxenkrug","year":"2010","unstructured":"Oxenkrug, G. F. Metabolic syndrome, age-associated neuroendocrine disorders, and dysregulation of tryptophan-kynurenine metabolism. Ann. N. Y. Acad. Sci. 1199, 1\u201314 (2010).","journal-title":"Ann. N. Y. Acad. Sci."},{"issue":"1\u20132","key":"3833_CR20","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.cca.2005.06.013","volume":"364","author":"K Schr\u00f6cksnadel","year":"2006","unstructured":"Schr\u00f6cksnadel, K., Wirleitner, B., Winkler, C. & Fuchs, D. Monitoring tryptophan metabolism in chronic immune activation. Clin. Chim. Acta Int. J. Clin. Chem. 364(1\u20132), 82\u201390 (2006).","journal-title":"Clin. Chim. Acta Int. J. Clin. Chem."},{"issue":"2","key":"3833_CR21","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1007\/s12035-013-8497-4","volume":"48","author":"G Oxenkrug","year":"2013","unstructured":"Oxenkrug, G. Insulin resistance and dysregulation of tryptophan-kynurenine and kynurenine-nicotinamide adenine dinucleotide metabolic pathways. Mol. Neurobiol. 48(2), 294\u2013301 (2013).","journal-title":"Mol. Neurobiol."},{"key":"3833_CR22","volume-title":"National Institute for Health and Care Excellence\u2014Obesity: Identification, Assessment and Management (NICE Guideline 189)","author":"NICE","year":"2014","unstructured":"NICE. National Institute for Health and Care Excellence\u2014Obesity: Identification, Assessment and Management (NICE Guideline 189) (NICE, 2014)."},{"issue":"8","key":"3833_CR23","doi-asserted-by":"crossref","first-page":"5207","DOI":"10.1021\/acs.analchem.8b05884","volume":"91","author":"L Whiley","year":"2019","unstructured":"Whiley, L. et al. Ultrahigh-performance liquid chromatography tandem mass spectrometry with electrospray ionization quantification of tryptophan metabolites and markers of gut health in serum and plasma-application to clinical and epidemiology cohorts. Anal. Chem. 91(8), 5207\u20135216 (2019).","journal-title":"Anal. Chem."},{"issue":"3","key":"3833_CR24","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1016\/j.clnu.2008.02.005","volume":"27","author":"P Crenn","year":"2008","unstructured":"Crenn, P., Messing, B. & Cynober, L. Citrulline as a biomarker of intestinal failure due to enterocyte mass reduction. Clin. Nutr. 27(3), 328\u2013339 (2008).","journal-title":"Clin. Nutr."},{"issue":"10","key":"3833_CR25","doi-asserted-by":"crossref","first-page":"1522","DOI":"10.1124\/dmd.115.064246","volume":"43","author":"TD Hubbard","year":"2015","unstructured":"Hubbard, T. D., Murray, I. A. & Perdew, G. H. Indole and tryptophan metabolism: Endogenous and dietary routes to ah receptor activation. Drug Metab. Dispos. 43(10), 1522\u20131535 (2015).","journal-title":"Drug Metab. Dispos."},{"issue":"1","key":"3833_CR26","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1111\/j.2517-6161.1995.tb02031.x","volume":"57","author":"Y Benjamini","year":"1995","unstructured":"Benjamini, Y. & Hochberg, Y. Controlling the false discovery rate: A practical and powerful approach to multiple testing. J. R. Stat. Soc. Ser. B (Methodol.) 57(1), 289\u2013300 (1995).","journal-title":"J. R. Stat. Soc. Ser. B (Methodol.)"},{"key":"3833_CR27","doi-asserted-by":"publisher","DOI":"10.3389\/fpsyg.2017.00456","author":"JZ Bakdash","year":"2017","unstructured":"Bakdash, J. Z. & Marusich, L. R. Repeated measures correlation. Front. Psychol. https:\/\/doi.org\/10.3389\/fpsyg.2017.00456 (2017).","journal-title":"Front. Psychol."},{"issue":"6977","key":"3833_CR28","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1136\/bmj.310.6977.446","volume":"310","author":"JM Bland","year":"1995","unstructured":"Bland, J. M. & Altman, D. G. Statistics notes: Calculating correlation coefficients with repeated observations: Part 1\u2014Correlation within subjects. BMJ (Clin. Res. Ed.) 310(6977), 446 (1995).","journal-title":"BMJ (Clin. Res. Ed.)"},{"issue":"6980","key":"3833_CR29","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1136\/bmj.310.6980.633","volume":"310","author":"JM Bland","year":"1995","unstructured":"Bland, J. M. & Altman, D. G. Calculating correlation coefficients with repeated observations: Part 2\u2014Correlation between subjects. BMJ (Clin. Res. Ed.) 310(6980), 633 (1995).","journal-title":"BMJ (Clin. Res. Ed.)"},{"issue":"1","key":"3833_CR30","doi-asserted-by":"crossref","first-page":"17025","DOI":"10.1038\/s41598-020-74183-w","volume":"10","author":"S G\u00fcrc\u00fc","year":"2020","unstructured":"G\u00fcrc\u00fc, S. et al. Neopterin and biopterin levels and tryptophan degradation in patients with diabetes. Sci. Rep. 10(1), 17025 (2020).","journal-title":"Sci. Rep."},{"issue":"10","key":"3833_CR31","doi-asserted-by":"crossref","first-page":"2066","DOI":"10.1002\/oby.21199","volume":"23","author":"M Favennec","year":"2015","unstructured":"Favennec, M. et al. The kynurenine pathway is activated in human obesity and shifted toward kynurenine monooxygenase activation. Obesity (Silver Spring) 23(10), 2066\u20132074 (2015).","journal-title":"Obesity (Silver Spring)"},{"issue":"3","key":"3833_CR32","doi-asserted-by":"crossref","first-page":"321","DOI":"10.3181\/00379727-88-21576","volume":"88","author":"DA Rosen","year":"1955","unstructured":"Rosen, D. A., Maengwyn-Davies, G. D., Becker, B., Stone, H. H. & Friedenwald, J. S. Xanthurenic acid excretion studies in diabetics with and without retinopathy. Proc. Soc. Exp. Biol. Med. 88(3), 321\u2013323 (1955).","journal-title":"Proc. Soc. Exp. Biol. Med."},{"issue":"23","key":"3833_CR33","doi-asserted-by":"crossref","first-page":"5501","DOI":"10.1007\/s00216-017-0486-4","volume":"409","author":"JS Oh","year":"2017","unstructured":"Oh, J. S. et al. Urinary profiling of tryptophan and its related metabolites in patients with metabolic syndrome by liquid chromatography-electrospray ionization\/mass spectrometry. Anal. Bioanal. Chem. 409(23), 5501\u20135512 (2017).","journal-title":"Anal. Bioanal. Chem."},{"issue":"2","key":"3833_CR34","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1007\/s12035-015-9232-0","volume":"52","author":"GF Oxenkrug","year":"2015","unstructured":"Oxenkrug, G. F. Increased plasma levels of xanthurenic and kynurenic acids in type 2 diabetes. Mol. Neurobiol. 52(2), 805\u2013810 (2015).","journal-title":"Mol. Neurobiol."},{"issue":"6","key":"3833_CR35","doi-asserted-by":"crossref","first-page":"e0158051","DOI":"10.1371\/journal.pone.0158051","volume":"11","author":"M Favennec","year":"2016","unstructured":"Favennec, M. et al. Post-bariatric surgery changes in quinolinic and xanthurenic acid concentrations are associated with glucose homeostasis. PLoS ONE 11(6), e0158051 (2016).","journal-title":"PLoS ONE"},{"issue":"2","key":"3833_CR36","doi-asserted-by":"crossref","first-page":"73","DOI":"10.5925\/jnsv1954.1.2_73","volume":"1","author":"Y Kotake","year":"1955","unstructured":"Kotake, Y. Xanthurenic acid, an abnormal metabolite of tryptophan and the diabetic symptoms caused in albino rats by its production. J. Vitaminol. (Kyoto) 1(2), 73\u201387 (1955).","journal-title":"J. Vitaminol. (Kyoto)"},{"issue":"1\u20136","key":"3833_CR37","first-page":"236","volume":"29","author":"Y Kotake","year":"1975","unstructured":"Kotake, Y., Ueda, T., Mori, T., Igaki, S. & Hattori, M. Abnormal tryptophan metabolism and experimental diabetes by xanthurenic acid (XA). Acta Vitaminol. Enzymol. 29(1\u20136), 236\u2013239 (1975).","journal-title":"Acta Vitaminol. Enzymol."},{"issue":"6","key":"3833_CR38","doi-asserted-by":"crossref","first-page":"2682","DOI":"10.1016\/S0041-1345(98)00788-X","volume":"30","author":"G Meyramov","year":"1998","unstructured":"Meyramov, G., Korchin, V. & Kocheryzkina, N. Diabetogenic activity of xanturenic acid determined by its chelating properties? Transpl. Proc. 30(6), 2682\u20132684 (1998).","journal-title":"Transpl. Proc."},{"key":"3833_CR39","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1186\/1472-6793-1-7","volume":"1","author":"HZ Malina","year":"2001","unstructured":"Malina, H. Z., Richter, C., Mehl, M. & Hess, O. M. Pathological apoptosis by xanthurenic acid, a tryptophan metabolite: Activation of cell caspases but not cytoskeleton breakdown. BMC Physiol. 1, 7 (2001).","journal-title":"BMC Physiol."},{"issue":"2","key":"3833_CR40","doi-asserted-by":"crossref","first-page":"275","DOI":"10.3181\/00379727-178-42010","volume":"178","author":"KS Rogers","year":"1985","unstructured":"Rogers, K. S. & Evangelista, S. J. 3-Hydroxykynurenine, 3-hydroxyanthranilic acid, and o-aminophenol inhibit leucine-stimulated insulin release from rat pancreatic islets. Proc. Soc. Exp. Biol. Med. 178(2), 275\u2013278 (1985).","journal-title":"Proc. Soc. Exp. Biol. Med."},{"key":"3833_CR41","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.mam.2016.08.001","volume":"53","author":"PM Ueland","year":"2017","unstructured":"Ueland, P. M., McCann, A., Midttun, \u00d8. & Ulvik, A. Inflammation, vitamin B6 and related pathways. Mol. Aspects Med. 53, 10\u201327 (2017).","journal-title":"Mol. Aspects Med."},{"issue":"2","key":"3833_CR42","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1093\/ajcn\/87.2.362","volume":"87","author":"ET Aasheim","year":"2008","unstructured":"Aasheim, E. T., Hofs\u00f8, D., Hjelmesaeth, J., Birkeland, K. I. & B\u00f8hmer, T. Vitamin status in morbidly obese patients: A cross-sectional study. Am. J. Clin. Nutr. 87(2), 362\u2013369 (2008).","journal-title":"Am. J. Clin. Nutr."},{"issue":"10","key":"3833_CR43","doi-asserted-by":"crossref","first-page":"3669","DOI":"10.3390\/ijms21103669","volume":"21","author":"E Mascolo","year":"2020","unstructured":"Mascolo, E. & Vern\u00ec, F. Vitamin B6 and diabetes: Relationship and molecular mechanisms. Int. J. Mol. Sci. 21(10), 3669 (2020).","journal-title":"Int. J. Mol. Sci."},{"key":"3833_CR44","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.ijcard.2015.03.413","volume":"189","author":"SJ Eussen","year":"2015","unstructured":"Eussen, S. J. et al. Kynurenines as predictors of acute coronary events in the Hordaland Health Study. Int. J. Cardiol. 189, 18\u201324 (2015).","journal-title":"Int. J. Cardiol."},{"key":"3833_CR45","doi-asserted-by":"crossref","first-page":"117864691769460","DOI":"10.1177\/1178646917694600","volume":"10","author":"S Debnath","year":"2017","unstructured":"Debnath, S. et al. Tryptophan metabolism in patients with chronic kidney disease secondary to type 2 diabetes: Relationship to inflammatory markers. Int. J. Tryptophan. Res. 10, 1178646917694600 (2017).","journal-title":"Int. J. Tryptophan. Res."},{"key":"3833_CR46","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1038\/s41581-020-0323-4","volume":"16","author":"NG Docherty","year":"2020","unstructured":"Docherty, N. G. & Le Roux, C. W. Bariatric surgery for the treatment of chronic kidney disease in obesity and type 2 diabetes mellitus. Nat. Rev. Nephrol. 16, 709 (2020).","journal-title":"Nat. Rev. Nephrol."},{"issue":"6","key":"3833_CR47","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1016\/S2213-8587(15)00134-5","volume":"3","author":"CD Moulton","year":"2015","unstructured":"Moulton, C. D., Pickup, J. C. & Ismail, K. The link between depression and diabetes: The search for shared mechanisms. Lancet Diabetes Endocrinol. 3(6), 461\u2013471 (2015).","journal-title":"Lancet Diabetes Endocrinol."},{"issue":"Pt B","key":"3833_CR48","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1016\/j.neuropharm.2016.07.002","volume":"112","author":"PJ Kennedy","year":"2017","unstructured":"Kennedy, P. J., Cryan, J. F., Dinan, T. G. & Clarke, G. Kynurenine pathway metabolism and the microbiota-gut-brain axis. Neuropharmacology 112(Pt B), 399\u2013412 (2017).","journal-title":"Neuropharmacology"},{"key":"3833_CR49","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.bbr.2014.07.027","volume":"277","author":"SM O\u2019Mahony","year":"2015","unstructured":"O\u2019Mahony, S. M., Clarke, G., Borre, Y. E., Dinan, T. G. & Cryan, J. F. Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behav. Brain Res. 277, 32\u201348 (2015).","journal-title":"Behav. Brain Res."},{"issue":"1","key":"3833_CR50","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1007\/s13340-016-0282-y","volume":"8","author":"K Matsuoka","year":"2017","unstructured":"Matsuoka, K. et al. Concentrations of various tryptophan metabolites are higher in patients with diabetes mellitus than in healthy aged male adults. Diabetol. Int. 8(1), 69\u201375 (2017).","journal-title":"Diabetol. Int."},{"issue":"6","key":"3833_CR51","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.jpsychores.2013.01.008","volume":"74","author":"D Keszthelyi","year":"2013","unstructured":"Keszthelyi, D. et al. Decreased levels of kynurenic acid in the intestinal mucosa of IBS patients: Relation to serotonin and psychological state. J. Psychosom. Res. 74(6), 501\u2013504 (2013).","journal-title":"J. Psychosom. Res."},{"issue":"7","key":"3833_CR52","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1080\/07853890.2018.1511917","volume":"50","author":"CW Lu","year":"2018","unstructured":"Lu, C. W. et al. Increased risk for major depressive disorder in severely obese patients after bariatric surgery\u2014A 12-year nationwide cohort study. Ann. Med. 50(7), 605\u2013612 (2018).","journal-title":"Ann. Med."},{"issue":"32","key":"3833_CR53","doi-asserted-by":"crossref","first-page":"19376","DOI":"10.1073\/pnas.2000047117","volume":"117","author":"SA Scott","year":"2020","unstructured":"Scott, S. A., Fu, J. & Chang, P. V. Microbial tryptophan metabolites regulate gut barrier function via the aryl hydrocarbon receptor. Proc. Natl. Acad. Sci. 117(32), 19376 (2020).","journal-title":"Proc. Natl. Acad. Sci."},{"issue":"2","key":"3833_CR54","doi-asserted-by":"crossref","first-page":"e13178","DOI":"10.1111\/nmo.13178","volume":"30","author":"M Jennis","year":"2018","unstructured":"Jennis, M. et al. Microbiota-derived tryptophan indoles increase after gastric bypass surgery and reduce intestinal permeability in vitro and in vivo. Neurogastroenterol. Motil. 30(2), e13178 (2018).","journal-title":"Neurogastroenterol. Motil."},{"issue":"1","key":"3833_CR55","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1186\/s40168-021-01086-x","volume":"9","author":"JV Li","year":"2021","unstructured":"Li, J. V. et al. Roux-en-Y gastric bypass-induced bacterial perturbation contributes to altered host-bacterial co-metabolic phenotype. Microbiome 9(1), 139 (2021).","journal-title":"Microbiome"},{"key":"3833_CR56","unstructured":"Society B-BOMS. NBSR Third Registry Report (2020)."},{"issue":"8","key":"3833_CR57","doi-asserted-by":"crossref","first-page":"1022","DOI":"10.1016\/j.soard.2020.04.007","volume":"16","author":"SK Raatz","year":"2020","unstructured":"Raatz, S. K. et al. Reported nutrient intake over 7 years after Roux-en-Y gastric bypass in the longitudinal assessment of bariatric surgery-3 (LABS-3) psychosocial study. Surg. Obes. Relat. Dis. 16(8), 1022\u20131029 (2020).","journal-title":"Surg. Obes. Relat. Dis."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-03833-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-03833-4","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-03833-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,9,15]],"date-time":"2024-09-15T17:39:21Z","timestamp":1726421961000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-03833-4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,7]]},"references-count":57,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["3833"],"URL":"https:\/\/doi.org\/10.1038\/s41598-021-03833-4","relation":{"has-preprint":[{"id-type":"doi","id":"10.21203\/rs.3.rs-569546\/v1","asserted-by":"object"}]},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,7]]},"assertion":[{"value":"28 May 2021","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"3 December 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"7 January 2022","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing interests.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"294"}}