Biodiversity screening of gut microbiome during autologous stem cell transplantation as a predictor of bloodstream infections in oncohematological patients

Abstract

Allogeneic HSCT is frequently associated with severe systemic infectious complications. Endogenous infections of intestinal origin are known to play a leading role in their occurence. Despite abundant data confirming the key role of gut microbiome in allogeneic HSCT, less is known about its role in autologous HSCT (ASCT). In this study, we aimed to investigate the characteristics of the gut microbiome that contribute to the development of bloodstream infections (BSI) in oncohematological patients during high-dose chemotherapy and AHSCT. We conducted a study on the microbial diversity of the gut microbiome during AHSCT in 30 patients with multiple myeloma (MM). The protocol involved stool sampling prior to AHSCT and during the post-transplant period. Our study revealed a significant decrease of the bacterial diversity index during AHSCT (p=0.02). The dominance of Proteobacteria in the intestinal microbiome proved to be an independent factor in the development of Gram-negative bloodstream infections in the patients. An increased ratio of Proteobacteria in the spectrum of gut microbiome over 30% is a reliable predictor of systemic Gram-negative bloodstream infections in patients undergoing high-dose chemotherapy and AHSCT. Therefore, monitoring biodiversity of intestinal microbiome is crucial in both allogeneic and autologous HSCT to identify high-risk groups for developing bloodstream infections. The stool samples for such monitoring should be evaluated both prior to HSCT, and post-transplant.