RT Journal Article SR Electronic T1 Obesity induces gut microbiota alterations and augments acute graft-versus-host disease after allogeneic stem cell transplantation JF Science Translational Medicine FD American Association for the Advancement of Science SP eaay7713 DO 10.1126/scitranslmed.aay7713 VO 12 IS 571 A1 Khuat, Lam T. A1 Le, Catherine T. A1 Pai, Chien-Chun Steven A1 Shields-Cutler, Robin R. A1 Holtan, Shernan G. A1 Rashidi, Armin A1 Parker, Sarah L. A1 Knights, Dan A1 Luna, Jesus I. A1 Dunai, Cordelia A1 Wang, Ziming A1 Sturgill, Ian R. A1 Stoffel, Kevin M. A1 Merleev, Alexander A. A1 More, Shyam K. A1 Maverakis, Emanual A1 Raybould, Helen E. A1 Chen, Mingyi A1 Canter, Robert J. A1 Monjazeb, Arta M. A1 Dave, Maneesh A1 Ferrara, James L. M. A1 Levine, John E. A1 Longo, Dan L. A1 Abedi, Mehrdad A1 Blazar, Bruce R. A1 Murphy, William J. YR 2020 UL http://stm.sciencemag.org/content/12/571/eaay7713.abstract AB Khuat et al. demonstrate that obesity worsens acute graft-versus-host disease (GVHD) outcomes in both mice and humans after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Using a diet-induced obese (DIO) mouse model, the authors observed increased lethal GVHD targeting the gut. DIO mice had increased gut permeability, endotoxin translocation into the bloodstream, and proinflammatory cytokine production, which correlated with reduced gut microbiota diversity. Manipulating the gut microbiota by antibiotic treatment partially protected DIO mice from lethal GVHD after allo-HSCT. Clinically, the authors found that patients with a high body mass index showed decreased gut microbiota diversity and poorer overall survival after allo-HSCT.The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by acute and chronic graft-versus-host disease (GVHD). The impact of obesity on allo-HSCT outcomes is poorly understood. Here, we report that obesity had a negative and selective impact on acute gut GVHD after allo-HSCT in mice with diet-induced obesity (DIO). These animals exhibited increased gut permeability, endotoxin translocation across the gut, and radiation-induced gastrointestinal damage after allo-HSCT. After allo-HSCT, both male and female DIO mouse recipients showed increased proinflammatory cytokine production and expression of the GVHD marker ST2 (IL-33R) and MHC class II molecules; they also exhibited decreased survival associated with acute severe gut GVHD. This rapid-onset, obesity-associated gut GVHD depended on donor CD4+ T cells and occurred even with a minor MHC mismatch between donor and recipient animals. Retrospective analysis of clinical cohorts receiving allo-HSCT transplants from unrelated donors revealed that recipients with a high body mass index (BMI, >30) had reduced survival and higher serum ST2 concentrations compared with nonobese transplant recipients. Assessment of both DIO mice and allo-HSCT recipients with a high BMI revealed reduced gut microbiota diversity and decreased Clostridiaceae abundance. Prophylactic antibiotic treatment protected DIO mouse recipients from endotoxin translocation across the gut and increased inflammatory cytokine production, as well as gut pathology and mortality, but did not protect against later development of chronic skin GVHD. These results suggest that obesity-induced alterations of the gut microbiota may affect GVHD after allo-HSCT in DIO mice, which could be ameliorated by prophylactic antibiotic treatment.