Streptococcus Salivarius K12 for Prevention and Treatment of Oral Mucositis in Patients Undergoing Radiotherapy

Streptococcus Salivarius K12 for Prevention and Treatment of Oral Mucositis in Patients Undergoing Radiotherapy for Head and Neck Tumor: A Randomized, Placebo-Controlled, Double-Blind Trial

To evaluate the efficacy and safety of Streptococcus salivarius K12 for prevention and treatment of oral mucositis in patients undergoing radiotherapy for malignant head and neck tumors.

The goal of this clinical trial is to evaluate the efficacy and safety of Streptococcus salivarius K12 in reducing the incidence, duration, and severity of severe oral mucositis (SOM). The main questions it aims to answer are whether Streptococcus salivarius K12 can effectively prevent and treat radiation-induced oral mucositis and whether it will cause adverse events in patients undergoing radiotherapy.

Participants will be instructed to suck a Streptococcus salivarius K12 or placebo lozenge three times daily from the beginning to the end of RT. After using the lozenges, the patients should avoid eating, drinking and conducting any oral hygiene activities for at least 1 hour.

Researchers will compare Streptococcus salivarius K12 group and placebo group to see if oral probiotic are beneficial in preventing and treating oral mucositis in patients undergoing radiotherapy.

Inclusion Criteria:

• Patients with non-metastatic head and neck malignant tumor diagnosed by histopathology;
• Aged 18 to 80 years;
• Systemic functional status Eastern Cooperative Oncology Group (ECOG) (Appendix 1) rating ≤2;
• Receiving definitive RT or postoperative adjuvant RT at a dose of 60-72Gy with/without concurrent chemotherapy;
• Sign the informed consent

Exclusion Criteria:

• Patients with known allergy to probiotic or severe allergic constitution;
• Using antibiotics/antifungal drugs within 1 month or using antimicrobial mouthwash within 1 week before the study;
• Poor oral hygiene and/or severe periodontal diseases;
• Any previous RT to the head and neck region;
• Deemed unsuitable for the study by the investigators (concomitant with any other severe diseases).