A randomized, double-blind, placebo-controlled trial of probiotics to reduce the severity of oral mucositis induced by chemoradiotherapy for patients with nasopharyngeal carcinoma

Background The objective of this study was to evaluate the effect of a probiotic combination on the severity of oral mucositis (OM), which is a common, unpreventable complication induced by radiochemotherapy in patients with nasopharyngeal carcinoma who undergo concurrent radiochemotherapy (CCRT). Methods Eligible patients (n = 99) with locally advanced nasopharyngeal carcinoma who were undergoing CCRT were randomly assigned (2:1) to receive a probiotic combination or placebo during radiochemotherapy, and the incidence of severe OM (grade 3 or higher) was the primary endpoint. Results Patients taking the probiotic combination showed a significant reduction in the severity of OM. The incidences of grade 0, 1, 2, and 3 OM in the placebo group and the probiotic combination group were 0% and 12.07%, 0% and 55.17%, 54.29% and 17.24%, and 45.71% and 15.52%, respectively. Furthermore, CCRT greatly lowered the number of immune cells, whereas the probiotic combination markedly lowered the reduction rates of CD4(+) T cells (76.59% vs 52.85%; P < .05), CD8(+) T cells (62.94% vs 29.76%; P < .05), and CD3(+) T cells (69.72% vs 45.49%; P < .05) in an A-CCRT-P (after treatment with radiotherapy plus chemotherapy plus the probiotic combination) group. High-throughput sequencing results indicated that CCRT had obviously disturbed the intestinal diversity of patients in an A-CCRT (after treatment with radiotherapy plus chemotherapy plus a placebo) group, whereas the probiotic combination distinctly restored the microbial diversity in the A-CCRT-P group toward that of healthy people and a B-CCRT-P (before the treatment of radiotherapy plus chemotherapy plus the probiotic combination) group. Conclusions A probiotic combination significantly enhances the immune response of patients and reduces the severity of OM through modification of gut microbiota.