{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T23:24:29Z","timestamp":1792884269317,"version":"4.5.0"},"reference-count":37,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,4]],"date-time":"2026-04-04T00:00:00Z","timestamp":1775260800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["860329"],"award-info":[{"award-number":["860329"]}]},{"DOI":"10.13039\/501100003130","name":"Fonds Wetenschappelijk Onderzoek","doi-asserted-by":"crossref","award":["1800820N"],"award-info":[{"award-number":["1800820N"]}],"id":[{"id":"10.13039\/501100003130","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100004040","name":"KU Leuven","doi-asserted-by":"crossref","award":["3M190551"],"award-info":[{"award-number":["3M190551"]}],"id":[{"id":"10.13039\/501100004040","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100004040","name":"KU Leuven","doi-asserted-by":"crossref","award":["C14\/21\/103"],"award-info":[{"award-number":["C14\/21\/103"]}],"id":[{"id":"10.13039\/501100004040","id-type":"DOI","asserted-by":"crossref"}]},{"award":["3M190551"],"award-info":[{"award-number":["3M190551"]}],"id":[{"id":"https:\/\/ror.org\/05f950310","id-type":"ROR","asserted-by":"publisher"}]},{"award":["C14\/21\/103"],"award-info":[{"award-number":["C14\/21\/103"]}],"id":[{"id":"https:\/\/ror.org\/05f950310","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Growing evidence suggests that chronic kidney disease (CKD) profoundly disrupts gut microbiome and its activity. This study explores how CKD affects colon microbial metabolism, focusing on (1) the representativeness of fecal metabolomics, (2) saccharolytic and proteolytic fermentation metabolites, and (3) the gut microbiome\u2019s role in the partitioning of tryptophan in its metabolic pathways. Tryptophan\u2019s main metabolic pathways include the indolic and the kynurenine pathways, which lead, respectively, to the formation of indoxyl sulfate and kynurenine, both contributing to uremic toxicity. Using a rat model of CKD, we evaluated whether fecal concentrations of microbial compounds, on which most studies are based, reflect the colonic concentrations in contact with the gut mucosa. Thus, we quantified the concentration and content of amino acids, indole, p-cresol, and also short-chain fatty acids, in different colon sections. We demonstrated that CKD promotes increased proteolytic fermentation and an augmented tryptophan partitioning into both the indolic and kynurenine pathways. Depletion of the indolic pathway obtained upon antibiotic treatment leads to a further enhancement of the kynurenine pathway.<\/jats:p>","DOI":"10.3390\/toxins18040176","type":"journal-article","created":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T01:12:33Z","timestamp":1775437953000},"page":"176","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Kidney Function Modulates Gut Microbial Metabolism"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9563-7757","authenticated-orcid":false,"given":"Mara","family":"Lauriola","sequence":"first","affiliation":[{"name":"Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium"},{"name":"Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000 Leuven, Belgium"},{"name":"Department of Nephrology and Renal Transplantation, UZ Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3019-550X","authenticated-orcid":false,"given":"Sophie","family":"Valkenburg","sequence":"additional","affiliation":[{"name":"Nephrology Section, Department of Internal Medicine and Paediatrics, Ghent University Hospital, 9000 Ghent, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5359-3028","authenticated-orcid":false,"given":"Sander","family":"Dejongh","sequence":"additional","affiliation":[{"name":"Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium"},{"name":"Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000 Leuven, Belgium"},{"name":"Department of Nephrology and Renal Transplantation, UZ Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9958-3474","authenticated-orcid":false,"given":"Ward","family":"Zadora","sequence":"additional","affiliation":[{"name":"Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium"},{"name":"Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000 Leuven, Belgium"},{"name":"Department of Nephrology and Renal Transplantation, UZ Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hubert","family":"Krukowski","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Bacteriology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium"},{"name":"Laboratory of Bioinformatics and (Eco-) Systems Biology, VIB, Center for Microbiology, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pieter","family":"Evenepoel","sequence":"additional","affiliation":[{"name":"Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium"},{"name":"Department of Nephrology and Renal Transplantation, UZ Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeroen","family":"Raes","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Bacteriology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium"},{"name":"Laboratory of Bioinformatics and (Eco-) Systems Biology, VIB, Center for Microbiology, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7158-171X","authenticated-orcid":false,"given":"Ricard","family":"Farr\u00e9","sequence":"additional","affiliation":[{"name":"Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7641-4707","authenticated-orcid":false,"given":"Griet","family":"Glorieux","sequence":"additional","affiliation":[{"name":"Nephrology Section, Department of Internal Medicine and Paediatrics, Ghent University Hospital, 9000 Ghent, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2846-2026","authenticated-orcid":false,"given":"Bj\u00f6rn","family":"Meijers","sequence":"additional","affiliation":[{"name":"Nephrology and Renal Transplantation Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium"},{"name":"Department of Nephrology and Renal Transplantation, UZ Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1111\/sdi.13030","article-title":"Feeling gutted in chronic kidney disease (CKD): Gastrointestinal disorders and therapies to improve gastrointestinal health in individuals CKD, including those undergoing dialysis","volume":"37","author":"Biruete","year":"2024","journal-title":"Semin. 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