Recently, a collaborative research effort between Professor Xingchen Peng's team from the Department of Biological Therapy at West China Hospital of Sichuan University and Professor Xin Xu's team from the Department of Endodontics at West China School of Stomatology has yielded promising results in the clinical management of radiation-induced oral mucositis. Their findings have been published online in the Journal of Clinical Oncology. This study, approached from the perspective of oral microbiota, marks the first discovery of the unique therapeutic efficacy of Streptococcus salivarius K12 in treating radiation-induced oral mucositis.
Radiotherapy plays a crucial role in the treatment of head and neck malignancies. However, oral mucositis is a common acute radiation-induced toxicity, affecting approximately 50% to 70% of patients undergoing head and neck radiotherapy, with a significant proportion experiencing severe oral mucositis (SOM). SOM leads to intense pain, difficulty in eating, a substantial impact on quality of life, treatment tolerance, and may even compromise the effectiveness of cancer therapy. Current clinical management options for radiation-induced oral mucositis are limited, with their efficacy and safety requiring further clinical validation.
Oral dysbiosis is recognized as a significant pathological factor in the development of radiation-induced oral mucositis. Streptococcus salivarius K12, a commensal bacterium isolated from the oral cavity of infants, exhibits strong oral colonization, low pathogenic potential, and beneficial effects on microbiota and host immunity. It has been utilized clinically in the management of oral candidiasis, pharyngitis, tonsillitis, halitosis, and otitis media.
Building upon years of research in radiation protection, the clinical trial conducted by the teams randomized patients into Streptococcus salivarius K12 intervention group and placebo group, administering either Streptococcus salivarius K12 or placebo during radiotherapy. The study dynamically monitored the occurrence and progression of radiation-induced oral mucositis and other oral complications (such as xerostomia and taste alterations), with a total of 143 patients completing the trial (ClinicalTrials.gov Identifier: NCT05918224).
Results revealed a significant reduction in the incidence and delayed onset of SOM in the Streptococcus salivarius K12 group compared to the placebo group, along with a notably shorter duration of symptoms. Only two patients in the Streptococcus salivarius K12 group experienced mild to moderate gastrointestinal adverse reactions (indigestion and bloating), and no severe drug-related adverse events were reported among all enrolled patients.
Microbiome analysis confirmed that local application of Streptococcus salivarius K12 during radiotherapy preserved the abundance of Streptococcus and other commensal bacterial genera in the oral cavity while inhibiting the growth of potentially pathogenic organisms. Streptococcus salivarius K12, recognized for its efficacy as an oral probiotic strain, offers advantages such as low toxicity and cost-effectiveness. This study challenges traditional concepts in the clinical diagnosis and management of radiation-induced oral mucositis and opens new avenues for further research in this field.
For more information, please refer to the related paper: https://ascopubs.org/doi/10.1200/JCO.23.00837.
