MICROBIOTA IN ORGAN TRANSPLANTATION: THERAPEUTIC PERSPECTIVES AND MECHANISTIC INSIGHTS: Edited by Jerzy W. Kupiec-WeglinskiEffects of obesity and weight-loss surgery shift the microbiome and impact alloimmune responsesZhou, Hao; Tullius, Stefan G.Author Information Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA Correspondence to Hao Zhou, MD, PhD, Division of Transplant Surgery & Transplant Surgery Research Laboratory, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, EBRC309, Boston, MA 02115, USA. Tel: +1 617 732 5659; e-mail: [email protected] Current Opinion in Organ Transplantation: December 2021 - Volume 26 - Issue 6 - p 603-608 doi: 10.1097/MOT.0000000000000920 Buy Metrics Abstract Purpose of review Obesity is a worldwide health problem with increasing rates in both children and adults. Bariatric surgery (BS) represents the only effective long-term treatment. Beneficial effects of BS may be mediated through shifts of the gut microbiome. Here, we introduce data linking the microbiome to alloimmune responses. Recent findings The rapid development of microbiome sequencing technologies in addition to the availability of gnotobiotic facilities have enabled mechanistic investigations on modulations of alloimmune responses through microbiomes. BS has been shown to improve comorbidities and chronic inflammation caused by obesity. Changes in microbiota and microbiota-related metabolites may play a role. Patients either listed or having received a transplant have undergone weight loss surgery, thus allowing to dissect mechanisms of microbial shifts to alloimmunity. Summary Weight loss and BS have the potential to improve transplant outcomes by ameliorating alloimmune responses. Those effects may be carried out through alterations of the gut microbiome. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.