The role of the gut microbiota in infectious complications during immunochemotherapy for diffuse large B-cell lymphoma

Background Infections are common complications and causes of death during immunochemotherapy in diffuse large B-cell lymphoma (DLBCL). The gut microbiota plays a significant role in bacterial infection, but its relationship and predictive capacity with infectious complications in DLBCL are unknown. Methods We performed 16S rRNA gene sequencing of fecal samples collected from 41 patients with newly diagnosed DLBCL at baseline, after every two cycles of standard immunochemotherapy, during infection, and after infection recovery. Analysis of the diversity and species composition of these samples was used to evaluate the relationship between gut microbiota and bacterial infection. Results Our findings demonstrate the dynamic changes of Enterobacteriaceae in patients with DLBCL during immunochemotherapy. The abundance of Enterobacteriaceae was markedly higher at baseline in patients who subsequently developed bacterial infection during immunochemotherapy than in those who did not (P < 0.0001), and showed a further increase during infection (P < 0.01), after recovery from the infection, the Enterobacteriaceae was significantly decreased (P < 0.001). While there was no significant change in patients who did not develop bacterial infection. The univariate and multivariate analysis showed that baseline abundance of Enterobacteriaceae > 4.5% was independently associated with post-immunochemotherapy bacterial infection. Conclusions Our findings suggest that the gut microbiota signatures differ between patients with DLBCL who do and do not develop bacterial infection. The baseline abundance of Enterobacteriaceae is associated with the post-immunochemotherapy bacterial infection, and it has certain predictive value. Detecting the changes of gut microbiota can help predict the risk of bacterial infection after immunochemotherapy.