Gut colonization by multidrug resistant organisms(MDROs) is a risk factor for bloodstream infections(BSI) in the early phase of Hematopoietic Stem Cell Transplantation(HSCT). We evaluated, in an exploratory study, the impact of Lactobacillus plantarum on modulation of the gut microbiome in HSCT patients colonized by MDROs. Participants were allocated to an intervention group(IG=22) who received capsules of L. plantarum(5x109 CFU) twice a day until the onset of neutropenia and a control group(CG=20). The V4 region of the 16S bacterial rRNA gene in 93 stool samples from a subset of 33 patients was sequenced(IG=20 and CG=13). Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) (PICRUSt2) program was used for prediction of metagenome functions. L. plantarum had an average 86%(±11%) drug-target engagement at 43(±29) days of consumption and it was safe, tolerable and associated with an increase in the abundance of the Lactobacillales(p=0.004). A significant increase of Lactococcus and reduction of Turicibacter(p<0.05) were identified on the second-week of L. plantarum use. Although Enterococcus abundance had a greater rise in the CG (p=0,07), there were no significant differences concerning the gram-negative MDROs. No serious adverse effects was reported in the IG. . We observed greater non-significant pyruvate fermentation to propanoate I (p=0.193) relative abundance in the IG comparing with CG.
L. plantarum use was safe and tolerable by HSCT patients. Although it may have impact on Enterococcus abundance and reduction of Turicibacter, it has not showed impact on Gram-Negative MDRO abundance in MDRO gram-negative colonized HSCT patients.