Oral microbiome dynamics in head and neck cancer patients undergoing oral healthcare: implications for prognosis and early diagnosis

Postoperative head and neck cancer (HNC) patients frequently experience oral microbiome dysbiosis and bad prognosis outcomes due to surgical trauma and reduced oral function, which may exacerbate symptoms and impair recovery. This study investigates how two oral mouthwash interventions—normal saline (N) and Yikou gargle (Y)—influence the oral microbiome at critical postoperative time points and explores their prognostic implications. Eighty HNC patients scheduled for surgery (30 requiring tracheostomy) were randomized into Group N or Group Y. Saliva samples were collected at baseline, post-operation, and pre-discharge. Using 16 S rRNA sequencing, we analyzed microbiome composition, compared community diversity, identified intervention-enriched taxa, and evaluated the clinical prognostic effects, such as dental issues. While both groups initially exhibited comparable microbiome diversity, Group Y demonstrated pronounced clustering distinct from the Group N. Streptococcus dominated both cohorts, but the Group Y exhibited reduced abundance of pathobionts, such as Haemophilus (LDA > 2, p < 0.05 ). Clinically, tracheostomy patients in Group Y reported reduced severity of dental complications (p = 0.019) and higher abundance of Abiotrophia (p = 0.003) compared to Group N counterparts. Our study provides insights into the impact of oral mouthwash interventions on the oral microbiome dynamics of HNC patients and their potential implications for prognosis. Understanding the role of the oral microbiome in HNC may pave the way for innovative therapeutic strategies that target the oral microbiota to improve treatment outcomes.