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.