Efficacy and safety of synbiotics in patients undergoing autologous hematopoietic stem cell transplantation: A prospective, randomized, double-blind, placebo-controlled pilot study

Abstract We aimed to assess the efficacy and safety of synbiotics, including live microorganisms and non-digestible food ingredients, in patients undergoing high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT). This prospective, randomized, double-blind study, included patients with malignant lymphoma eligible for auto-HSCT. The patients were randomized to either a synbiotic group receiving Bifidobacterium longum (BB536) and guar gum or a placebo group receiving a placebo including dextrin. The supplements were administered twice daily from the start of conditioning chemotherapy up to 28 days after auto-HSCT. The primary endpoint was the duration of total parenteral nutrition (TPN). The secondary endpoint was safety. A total of 12 patients were included and randomized. The median duration of TPN was 15 days (range, 12–33 days) in the synbiotic group and 17.5 days (range, 0–32 days) in the placebo group, with no clear difference between the two groups. The median duration of grade 3 or higher diarrhea was shorter in the synbiotic group (2.5 vs. 6.5 days), as was the duration of hospital stay (31.5 vs. 43 days). Oral intake and quality of life regarding diarrhea and anorexia improved in the synbiotic group after engraftment. Synbiotic infections, including bacteremia, were not observed. Synbiotics may reduce gastrointestinal toxicity leading to nutritional problems and improve the quality of life of patients undergoing auto-HSCT, without severe adverse events. (The Japan Registry of Clinical Trials, No. jRCTs051180026.)