Fecal Microbial Signatures Are Associated With Engraftment Failure Following Umbilical Cord Blood Transplantation in Pediatric Crohn's Disease Patients With Deficiency

Objectives: Umbilical cord blood transplantation (UCBT) is associated with a relatively high rate of engraftment failure. This study aimed at exploring whether any fecal microbiota could be associated with engraftment failure following UCBT in Crohn's disease patients with deficiency.

Methods: Thirteen patients were recruited and their 230 fecal samples were collected longitudinally from immediately before conditioning chemotherapy to 8 weeks post the UCBT. The V3-V4 regions of the bacterial 16S rRNA gene were amplified by PCR and sequenced, followed by bioinformatics analyses.

Results: Following the UCBT, 7 out of 13 patients achieved neutrophil and platelet engraftment with a median of 21 and 28 days, respectively (S group), while 6 patients failed to achieve engraftment (F group). In comparison with that in the S group, significantly lower Shannon diversity values on the UCBT day ( = 0.0176) and less abundance of , , , and one taxon of family was detected in the F group, accompanied by significantly higher abundances of four taxa including , , and species during the chemotherapy period as well as UCBT. The abundances of thirty OTUs were correlated significantly with clinical indices.

Conclusions: Microbial indicators of reduced diversity of microbiota and signatures of specific bacterial abundances, such as a lower abundance of , for engraftment failure would require validation. These indicators may help for the risk stratification in patients with deficiency undergoing UCBT.