Intestinal flora plays an essential role in regulating immune responses. Changes in the gut flora are associated with poor prognosis after allogeneic hematopoietic stem cell transplantation (HSCT). We aimed to investigate the impact of diverse intestinal flora on survival after allogeneic HSCT. Using next-generation sequencing of the bacterial 16S ribosomal RNA (rRNA) gene, we found that the intestinal microbiota of patients undergoing allogeneic HSCT differed significantly from that of healthy controls. Furthermore, dysbiosis persisted for at least 1 year after transplantation. Interestingly, increased abundance of the genus Enterococcus detected by 16S rRNA sequencing as early as 1 month after transplantation was correlated with poor survival (overall survival at 2 years post-HSCT, 83.9% for patients with <1% relative abundance of Enterococcus and 47.6% for those with ≥1% relative abundance of Enterococcus), which was undetectable by conventional standard stool culture. These findings suggest that detection of Enterococcus by 16S rRNA analysis reflects compromised intestinal flora and may be a promising prognostic indicator.

中文翻译：

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肠球菌：异基因造血干细胞移植后微生物群破坏和预后不良的预测因子。

肠道菌群在调节免疫反应中起着至关重要的作用。异基因造血干细胞移植（HSCT）后肠道菌群的变化与预后不良有关。我们旨在调查异基因HSCT后不同肠道菌群对存活的影响。使用细菌16S核糖体RNA（rRNA）基因的下一代测序，我们发现同种异体HSCT患者的肠道菌群与健康对照者显着不同。此外，移植后营养不良持续至少一年。有趣的是，最早在移植后1个月通过16S rRNA测序检测到的肠球菌属丰度增加与存活率差有关（HSCT后2年的总存活率为83.9％，< 肠球菌的相对丰度为1％，肠球菌的相对丰度≥1％的那些为47.6％），这是常规标准粪便培养法无法检测到的。这些发现表明，通过16S rRNA分析检测肠球菌反映了肠道菌群受损，可能是有希望的预后指标。