biostudies-literatureHayase EAmerican Society for Transplantation and Cellular TherapyNIDDK NIH HHSNational Marrow Donor ProgramNHLBI NIH HHSNCI NIH HHSNational Institutes of HealthDKMS Foundation UKCancer Prevention and Research Institute of Texas1621-1636.e6https://www.ebi.ac.uk/biostudies/studies/S-EPMC11441101biostudies-literatureUnknown32(9)Acute lower gastrointestinal GVHD (aLGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation. Although the intestinal microbiota is associated with the incidence of aLGI-GVHD, how the intestinal microbiota impacts treatment responses in aLGI-GVHD has not been thoroughly studied. In a cohort of patients with aLGI-GVHD (n = 37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and a disrupted fecal microbiome characterized by reduced abundances of Bacteroides ovatus. In a murine GVHD model aggravated by carbapenem antibiotics, introducing B. ovatus reduced GVHD severity and improved survival. These beneficial effects of Bacteroides ovatus were linked to its ability to metabolizCell host & microbeBacteroides ovatus alleviates dysbiotic microbiota-induced graft-versus-host disease.PMC11441101P01 HL170046P30 CA016672R01 HL158796P30 CA008748P30 DK056338R35 HL155672K08 HL143189R01 HL124112Wong MCMcDaniel LKPham DKatsamakis ZPrasad ROkhuysen PCMukherjee AWargo JASchmiester MChang CCFowler SWOrtega MRTan LBritton RAStinson SCGlover IKBurgos da Silva MKing KYJin YKarmouch JLJamal MAPonce DMMartens ECMohammed AHalsey TMMehta RSAlousi AMReddy PAjami NJHayase EEnkhbayar ALorenzi PLvan den Brink MRMPeterson CBRondon GAhmed SSBrown ANTsai WBMolldrem JJShpall EJTran BQFan CSanchez CAXiao YPeled JUJenq RRChapa VAConner MESmith NShelburne SLiu CFlores IIEl-Himri RKHayase TChamplin REfalseBacteroides ovatus alleviates dysbiotic microbiota-induced graft-versus-host disease.Acute lower gastrointestinal GVHD (aLGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation. Although the intestinal microbiota is associated with the incidence of aLGI-GVHD, how the intestinal microbiota impacts treatment responses in aLGI-GVHD has not been thoroughly studied. In a cohort of patients with aLGI-GVHD (n = 37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and a disrupted fecal microbiome characterized by reduced abundances of Bacteroides ovatus. In a murine GVHD model aggravated by carbapenem antibiotics, introducing B. ovatus reduced GVHD severity and improved survival. These beneficial effects of Bacteroides ovatus were linked to its ability to metaboliz2024-01-01T00:00:00Z2024 Sep2026-06-03T05:46:54.592Z2026-04-25T03:14:45.514ZS-EPMC114411013921408510.1016/j.chom.2024.08.004