The Oral Microbiome and Upper Aerodigestive Squamous Cell Cancer

The human oral cavity is a diverse habitat that contains approximately 700 prokaryotic species. The oral microbiome is comprised of 44% named species, 12% isolates representing unnamed species, and 44% phylotypes known only from 16S rRNA based cloning studies (http://www.homd.org/). Species from 11 phyla have been identified: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Spirochaetes, Fusobacteria, TM7, Synergistetes, Chlamydiae, Chloroflexi and SR1 (http://www.homd.org/). Because these observations have been mainly based on data generated from traditional Sanger sequencing, the diversity of oral microbiome is highly likely underestimated. Application of high throughput sequencing to the oral microbiome similar to the scale of the microbiome studies of other body sites (GI tract, skin, and vagina) under the Human Microbiome Project is necessary to obtain data essential for understanding the diversity and community structure of the oral microbiome in health and disease.