Purpose: Acute graft versus host disease (aGVHD) is a major cause of non-relapse morbidity and mortality post-allogenic hematopoietic stem cell transplant (HSCT). Using conventional literature search and computational approaches, our objective was to identify oral and gut bacterial species associated with aGVHD, potentially affecting drug treatment via lipopolysaccharide (LPS) pathways.
Methods: Medline, PubMed, PubMed Central, and Google Scholar were searched using MeSH terms. The top 100 hits per database were curated, and 25 research articles were selected to examine oral and gut microbiomes associated with health, HSCT, and aGVHD. Literature search validation, aGVHD drug targets, and microbial metabolic pathway identification were completed using BioReader, MACADAM, KEGG, and STRING programs.
Results: Our review determined that (1) oral genera Rothia, Solobacterium, and Veillonella were identified in HSCT patients' stool and associated with aGVHD; (2) shifts in gut enterococci profiles were determined in HSCT-associated aGVHD; (3) gut microbiome dysbiosis prior or during HSCT and lower Shannon diversity index at time of HSCT were also associated with increased risk of aGVHD and transplant related death; and (4) Coriobacteriaceae family was negatively correlated with gut aGVHD, whereas Eubacterium limosum was associated with decreased risk of chronic GVHD relapse. Additionally, we identified molecular pathways related to TLR4/ LPS, including candidate aGVHD drug targets, impacted by oral and gut bacterial taxa.
Conclusion: Reduced microbial diversity reflects higher severity and mortality rate in HSCT patients with aGVHD. Multi-omics approaches to decipher oral and gut microbiome associations will be critical for developing aGVHD preventive therapies.
Keywords: Acute graft versus host disease; Computational drug discovery; Gut microbiome; Hematopoietic stem cell transplant; Oral microbiome; Text mining.