The effectiveness of probiotics in prevention and treatment of cancer therapy-induced oral mucositis: A systematic review and meta-analysis.

Oral mucositis (OM) is a common and troublesome adverse side effect of many cancer therapy modalities (chemotherapy, radiotherapy, and chemo-radiotherapy), which can cause pain, ulceration, dysphagia, malnutrition, even treatment interruption. Probiotics may be effective in preventing and treating of cancer therapy-induced OM. We performed a systematic review and meta-analysis of the effectiveness of probiotics in prevention and treatment of cancer therapy-induced OM. Four databases and one trial registry were searched as of the 12th of May 2019 to identify all eligible randomized controlled trials (RCT). Five studies involving 435 patients were included in this study. Methodological quality and outcomes were evaluated in every study included. Pooled results showed a moderate heterogeneity (P = 0.15, I2 = 44%). The pooled RRs indicated that the use of probiotics decreased the risk of OM for grade ≥3 (RR = 0.66, 95%CI = 0.54-0.81, P < 0.0001) as well as all grades (RR = 0.83, 95% CI = 0.72-0.97, P = 0.02). There was no significant difference between probiotics and placebo for cancer therapy completion rate (RR = 1.14, 95%CI = 0.65-2.00, P = 0.64). The subgroup analysis indicated that the use of probiotics was not statistically significant for patients receiving chemo-radiotherapy (RR = 0.52, 95% CI = 0.26-1.04, P = 0.07). In conclusion, probiotics may reduce the incidence and mitigate the severity of cancer therapy-induced OM. Further trials with a randomized, double-blind and multicentric study design are needed to confirm this effect. The PROSPERO registration number of this systematic review and meta-analysis is CRD42019130414.