Oral microbiome and risk of incident head and neck cancer: A nested case-control study

•The oral microbiome may play a role in the etiology of head and neck cancer.•The oral microbial alpha and beta diversity did not significantly differ between head and neck cancer cases and controls.•The presence of oral fungi was associated with reduced risk of head and neck cancer.•The presence and relative abundance of multiple microbial species, including the red- and orange-complex periodontal pathogens, were associated with reduced risk of head and neck cancer.•Future studies with larger sample sizes are needed to evaluate these associations.