Disruption of the intestinal microbiota caused by intensive chemotherapy, irradiation and antibiotics can result in development of severe gut graft-versus-host disease and infectious complications, leading to poorer outcomes among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Although the oral cavity is also densely colonized by indigenous microorganisms, the bacterial composition in allo-HSCT recipients remains unclear. We determined the tongue microbiota composition of 45 patients with hematological disorders on the day of transplantation and compared them to 164 community-dwelling adults. The V1–V2 regions of the 16S rRNA gene sequences demonstrated that the allo-HSCT recipients had less diverse and distinct microbiota from that of community-dwelling adults. The full-length 16S rRNA gene sequences identified 146 bacterial taxa in the microbiota of allo-HSCT recipients, of which 34 bacterial taxa did not correspond to bacteria primarily inhabiting the oral cavity deposited in the expanded Human Oral Microbiome Database. Notably, the detection of Staphylococcus haemolyticus and/or Ralstonia pickettii was significantly associated with a higher risk of mortality during the follow-up period. These results demonstrate that the oral cavity of allo-HSCT recipients is colonized by a disrupted microbiota on the day of transplantation and suggest that detection of specific nonindigenous taxa could be a predictor of transplant outcome.

强化化疗，放疗和抗生素引起的肠道菌群破坏可能导致严重的肠道移植物抗宿主病和感染性并发症的发生，导致同种异体造血干细胞移植（allo-HSCT）接受者的预后较差。尽管口腔也被本地微生物密集地定殖，但是异源-HSCT接受者中的细菌组成仍然不清楚。我们确定了移植当天45例血液学疾病患者的舌菌群组成，并将其与164位社区居民进行了比较。16S rRNA基因序列的V1-V2区域表明，异源-HSCT受体的微生物群不同于社区居民的微生物群。全长16S rRNA基因序列在异源HSCT受体的微生物群中鉴定出146个细菌分类群，其中34个细菌分类群与主要居住在扩展的人类口腔微生物组数据库中的口腔细菌不符。值得注意的是，在随访期间，溶血性葡萄球菌和/或Ralstonia pickettii与较高的死亡风险显着相关。这些结果表明，异体-HSCT受体的口腔在移植当天就被微生物群破坏了，并表明检测到特定的非本地分类群可能是移植结果的预测指标。