Oral microbiota in head and neck cancer patients during radiotherapy: a systematic review.

Purpose: Radiotherapy (RT) in the head and neck (HN) area causes a series of oral complications and the oral microbiota may play an important role in these complications. The aim of this systematic review was to explore alterations in the oral microbiota among individuals undergoing RT in the HN region.

Methods: A comprehensive search across six databases and grey literature was made. No limitations were imposed on language or publication year. Studies meeting the inclusion and exclusion criteria were considered for inclusion.

Results: Twenty-six articles met the criteria for inclusion in this systematic review. These studies varied in terms of radiation doses administered (ranging from 40 Gy to 82.60 Gy), microorganisms analyzed, locations within the oral cavity examined, and timing of assessments. Additionally, different methods of analysis were employed by the studies. Regarding oral microbiota changes, post-RT, there was significant increase in Candida species. Bacterial microbiota experienced increases, notably including Streptococcus mutans (S.mutans) and Lactobacillus, with dynamic fluctuations.

Conclusion: RT in the HN region induces significant changes in oral microbiota, including increases in S. mutans, Lactobacillus and Candida species colonization, and decreases in beneficial bacteria such as Neisseria and Fusobacteria. These microbiota changes may contribute to oral complications post-RT, emphasizing the need for preventive measures and targeted therapies to manage oral health in HN cancer patients undergoing RT.