Association of Salivary Microbes with Oral Mucositis Among Patients Undergoing Chemoradiotherapy in Head and Neck Cancer: A Hospital-Based Prospective Study

Aim: To evaluate oral salivary microbes and associate them with chemoradiotherapy-induced oral mucositis in HNC patients. Materials and Method: This was a prospective cohort study on 21 head and neck cancer patients using simple random sampling; those undergoing chemoradiotherapy were evaluated for oral mucositis based on WHO criteria. Controls were healthy volunteers n = 8. Salivary samples were collected at the following 3 time points in patients undergoing chemoradiotherapy: day 1 (before chemoradiotherapy), day 7, and day 30 and from controls. Progression of oral mucositis according to grades on days 1, 7, and 30 was analyzed using Friedman tests. Clinical and microbiological profiles, the variations in the microbiota with increase in grades of OM as the day progresses were analyzed. Data were analyzed using SPSS. Association of grading of oral mucositis according to progress in days with different microbial colonization were analyzed using chi-squared test. Level of significance was set at P < 0.05. Results: Predominance of Streptococci species followed by Candida and other Gram-negative bacteria were observed on day 1 before chemoradiotherapy. Gradual increase in the Candida and Gram-negative species was observed after chemoradiotherapy progressing to gradual rise from Day 7 toward day 30 and is associated with moderate to severe OM (Grade > 2). There was a statistically significant difference in grading of oral mucositis between Day 1 and Day 30 (P < 0.01), Day 7 and Day 30 (P < 0.01). The overall microbial profile was as follows: Candida albicans (71.4%, n = 15), Candida tropicalis (57.14%, n = 12), Enterococcus faecalis (42.85%, n = 9), Klebsiella pneumoniae (61.09%, n = 13), Pseudomonas aeruginosa (76.19%, n = 16), Streptococcus pneumoniae (19.04%, n = 4), and Viridans streptococci (14.28%, n = 3) were observed on day 30.The results were statistically significant with a P value 0.048, P < 0.05. Conclusion: There was a change in oral microbiota in head and neck cancer patients during chemoradiotherapy over a time period. Salivary microbes were associated with the severity of OM thus reflecting the disease status. Novel drugs with antimicrobial properties with fewer side effects are recommended that prevent and treat OM in head and neck cancer patients.

Automated summary

This study evaluated salivary microbes in head and neck cancer patients and their association with chemoradiotherapy-induced oral mucositis. The results showed that there were changes in oral microbiota during chemoradiotherapy, and these changes were associated with the severity of mucositis, reflecting the disease status.