{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T20:28:30Z","timestamp":1790022510759,"version":"4.0.1"},"posted":{"date-parts":[[2026,5,10]]},"group-title":"Microbiology","reference-count":50,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,5,10]],"date-time":"2026-05-10T00:00:00Z","timestamp":1778371200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.biorxiv.org\/about\/FAQ#license"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"crossref","award":["R01 CA266068"],"award-info":[{"award-number":["R01 CA266068"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"crossref","award":["R01 AI196346"],"award-info":[{"award-number":["R01 AI196346"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"crossref","award":["P01 AI179406"],"award-info":[{"award-number":["P01 AI179406"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"crossref","award":["R00AI175599"],"award-info":[{"award-number":["R00AI175599"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Ministerio de Ciencia, Innovaci\u00f3n y Universidades","award":["RYC2023-042654-I"],"award-info":[{"award-number":["RYC2023-042654-I"]}]},{"name":"Ministerio de Ciencia, Innovaci\u00f3n y Universidades","award":["PID2024-160934OA-I00"],"award-info":[{"award-number":["PID2024-160934OA-I00"]}]},{"DOI":"10.13039\/100009784","name":"Starr Foundation","doi-asserted-by":"crossref","award":["I13-0013"],"award-info":[{"award-number":["I13-0013"]}],"id":[{"id":"10.13039\/100009784","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,5,10]]},"abstract":"<jats:title>SUMMARY<\/jats:title>\n                <jats:p>\n                  The kynurenine pathway (KP) of tryptophan metabolism shapes host immunity and is implicated in inflammatory, malignant, and neurodegenerative diseases. Although it is well known that inflammation influences KP activity, whether and how gut microbiota regulates KP in the intestine remains unclear. Here, we find that in allogeneic hematopoietic cell transplant patients, the kynurenine-to-tryptophan ratio tracks plasma neopterin, whereas intestinal levels do not, suggesting that local KP regulation is not explained by inflammation alone. In mice, targeted microbiota perturbation downregulates intestinal expression of indoleamine 2,3-dioxygenase 1 (IDO1), the rate-limiting enzyme of the KP, while microbiota restoration reversed this effect. Computational analyses associate Lachnospiraceae and Oscillospiraceae with colonic IDO1 in mice and inflammatory bowel disease cohorts.\n                  <jats:italic>In vitro<\/jats:italic>\n                  experiments support a mechanism whereby microbiota perturbation alters host absorption of the vitamin E isoform, \u03b3-tocotrienol, which impacts IDO1 expression. Our findings support that the gut microbiota controls colonic KP through micronutrient absorption.\n                <\/jats:p>","DOI":"10.64898\/2026.05.08.723850","type":"posted-content","created":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T04:50:16Z","timestamp":1778475016000},"source":"Crossref","is-referenced-by-count":1,"title":["Gut Commensals Regulate the Intestinal Kynurenine Pathway"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8068-7188","authenticated-orcid":false,"given":"Ana","family":"Djukovic","sequence":"first","affiliation":[{"name":"Microbiome Mechanisms in Health and Disease Laboratory, Centro de Investigaci\u00f3n Pr\u00edncipe Felipe, Valencia, Spain"},{"name":"Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chen","family":"Liao","sequence":"additional","affiliation":[{"name":"Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA"},{"name":"Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth, Hanover, New Hampshire, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andras","family":"Bimbo-Szuhai","sequence":"additional","affiliation":[{"name":"Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA"},{"name":"Icahn School of Medicine at Mount Sinai, New York, New York, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chloe","family":"Lindberg","sequence":"additional","affiliation":[{"name":"Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA"},{"name":"Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui","family":"Liu","sequence":"additional","affiliation":[{"name":"Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hannah","family":"Lees","sequence":"additional","affiliation":[{"name":"Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruben J. F.","family":"Ramos","sequence":"additional","affiliation":[{"name":"Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Justin R.","family":"Cross","sequence":"additional","affiliation":[{"name":"Donald B. and Catherine C. 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