220P - Correlation research between oral flora diversity and radiation-induced stomatitis after postoperative radiotherapy for oral squamous cell carcinoma

Background

Radiation oral mucositis (radiotherapy-induced oral mucositis, RIOM), as one of the common complications during radiotherapy, is difficult to avoid and predict. Severe RIOM will reduce the quality of life of patients and affect the normal progress of diagnosis and treatment. Early detection and early intervention is very important to reduce the incidence of RIOM, but at present, the sensitivity and specificity of clinical indicators for the occurrence and development of radiation stomatitis are poor, so it is necessary to study further the treatment factors and predictive indicators of radiation stomatitis. It has been found that oral flora are closely related to the progression of radiation oral mucositis.

Methods

27 postoperative patients with oral squamous cell carcinoma were enrolled in the study. The cotton swab samples of oral buccal mucosa before and after radiotherapy were collected. The diversity, species differences and marker species of the oral microbial community were determined by 16 S rRNA sequencing and metagenome sequencing.

Results

Compared with the pre-radiotherapy group, the composition of oral flora in the radiotherapy group and the post-radiotherapy group changed, and the community diversity decreased significantly. The richness of different flora was different. In terms of genera, there was a difference in the richness of Haemophilus during radiotherapy, after radiotherapy and before radiotherapy, and the number of different bacteria was positively correlated with the time of radiotherapy. At the species level, the diversity of Streptococcus pneumoniae and Haemophilus haemolyticus increased significantly after radiotherapy. In terms of functional distribution, based on KEGG and CAZymes database, there were differences in functional distribution between the two groups of oral flora.

Conclusions

Radiotherapy can change the species structure and composition of oral flora and reduce community diversity. Streptococcus pneumoniae and Haemophilus haemolyticus may be related to the occurrence and development of radiation oral mucositis.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.