RESUMO
BACKGROUND: In the pediatric oncology population, oral mucositis as a consequence of chemotherapy is a highly prevalent complication which strongly affects both the quality of life and treatment possibilities of the patients. Still, the etiopathological mechanisms carrying to its development are not fully understood, although a possible role of oral dysbiosis has been previously investigated with unclear conclusions. The aim of this systematic review was to assess the available evidence on the role of microbiota in the development of oral mucositis. METHODS: A systematic literature search was performed following PRISMA guidelines. Three electronic databases were searched up until April 2023 and a following manual search included the reference lists of the included studies and reviews. Studies reporting microbiological and clinical data of pediatric patients treated by antineoplastic drugs were included. RESULTS: Thirteen studies met the inclusion criteria, reporting an average mucositis prevalence of 57,6%. Candida albicans infections were frequently observed in studies performing microbiological analysis on oral lesions, in contrast with the low rate detection of the Herpes simplex viruses. Bacterial species such as coagulase-negative Staphylococci and Streptococcus viridans were detected more frequently on lesion sites. Studies reporting a quantitative analysis of the general flora did not show comparable results. Risk of bias assessment among studies was generally considered high or very high. CONCLUSIONS: While the specific role of certain microbiological agents, such as Candida albicans, was frequently reported among studies, data regarding the general dynamics of oral microbiota in the development of oral mucositis are lacking in the current literature. Thus, more studies are needed to provide the knowledge required in order to improve protocols for the prevention and treatment of this threatening complication.