According to a report in Blood, fecal microbiome health may predict outcomes in patients with graft-versus-host disease (GVHD) after undergoing allogeneic hematopoietic stem cell transplantation (HSCT). The authors also found microbial dysbiosis was observable in samples from patients with gastrointestinal (GI) acute GVHD (aGVHD) during the period of GVHD onset.
The study reviewed 1303 stool samples from 266 recipients of allogeneic HSCT using 16s ribosomal gene sequencing. Patients were stratified according to aGVHD organ involvement and assessed for relationships between fecal microbiome features and aGVHD pathophysiology.
Butyrate Producer Abundance and Other Markers Predict GVHD Prognosis
Compared with HSCT recipients who did not develop GVHD, researchers found patients who developed GVHD had lower abundance of Clostridia class members, lower butyrate producer counts, and lower strict-to-facultative (S/F) anaerobic bacteria ratios in the 20 days prior to GVHD onset.
Authors also noted patients with GI GVHD had a significant reduction in microbiome diversity before disease onset, and patients with lower GI involvement showed lower S/F anaerobe ratios compared with patients with upper GI involvement. In addition, the authors observed that in the 20 days following GVHD onset, only patients with GI involvement exhibited microbial dysbiosis, particularly those with lower-tract disease.
Of note, abundance of Clostridial and butyrate producers and S/F anaerobe ratio were predictive factors for longer overall survival. Furthermore, a higher butyrate-producer abundance and S/F ratio were associated with reduced risk of GVHD-related mortality.
Ultimately, the study’s authors suggested that “the intestinal microbiome can serve as a biomarker for outcomes of [allogeneic HSCT] patients with GVHD,” with the potential to accurately stratify patients according to risk.
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