Intestinal microbiome diversity and clinical outcomes with multiple myeloma: A systematic review.

Abstract

e20542 Background: Human gastrointestinal microbiome (GM) plays a role in food digestion, drug metabolism and protection against infections. We systematically reviewed the outcomes for multiple myeloma (MM) patients (pts) and its changes in GM diversity (GMD) with regimen-related toxicities. Methods: After a systematic search of PubMed, Embase, Web of Science, Cochrane, and Clinicaltrials.gov (until 01/12/2020), 9 out of 135 studies met our inclusion criteria. Results: GM changes were studied in 1343 pts. 1070 pts received Autologous (Auto) and 119 pts received Allogeneic (Allo) hematopoietic cell transplantation (HCT). 1. Impact of Induction without HCT: Higher levels of Eubacterium hallii and Faecalibacterium prausnitzii in 16 (MM) minimal residual disease (MRD) –ive pts and lower levels in 18 (MM) MRD +ive pts were noted (Pianko 2019). 2. Impact of HCT and microbiome: 1142 pts (MM = 1011) were studied; day+15 samples showed reduction of Bacteroidetes in Auto-HCT compared with Allo-HCT pts. Pts with graft versus host disease (GVHD) harbored more Firmicutes, Proteobacteria and less Bacteroidetes than pts without GVHD (Chiusolo 2015). Day+30 fecal samples (FS) revealed increase in Proteobacteria, Clostridium difficile and decrease in Firmicutes, Fusarium in FS while oral samples (OrS) showed increase in Firmicutes and decrease in Proteobacteria and Glomerella. Increased gastrointestinal adverse effects (AEs) (40%) correlated with decreased GMD especially in pts with ulcerative oral mucositis (OM) (Alexa 2019, El-Jurdi 2019, Apewokin 2015). At 3 years, Allo-HCT pts with highest GMD manifested least treatment-related mortality (TRM) (9%) and vice versa (Taur 2014). 3. Impact of Post-HCT Lactobacillus Probiotics (LBP) or Antibiotics: Improvement in AEs with LBP was statistically insignificant (Gorshein 2017, Giammarco 2016). Pts showed better clinical outcomes with ciprofloxacin and metronidazole (Cp-M) (n = 68) than Ciprofloxacin (n = 66) alone; i.e. overall survival (49% vs 42%), increased number of FS without anaerobic bacteria (53% vs 23%), GVHD (25% vs 50%), OM (82% vs 92%) (Beelen 1999). Conclusions: Treatment for MM alters microbiome diversity. Increased diversity was associated with fewer gastrointestinal AEs. Improvement in AEs with LBP was statistically insignificant. Post-HCT use of Cp-M showed better overall survival.

The Role of the Gut Microbiome in Pathogenesis, Biology, and Treatment of Plasma Cell Dyscrasias

“…Their role is particularly visible in respect of possible infectious complications after treatment that are due to infection. It was recently confirmed that treatment of MM changes the composition of the gut microbiome in respect of diversity (70).…”