More than a dozen bacterial species among the hundreds that live in people’s mouths have been linked to a collective 50 percent increased chance of developing head and neck squamous cell carcinoma (HNSCC), a new study shows.

Experts have long observed that those with poor oral health are statistically more vulnerable than those with healthier mouths to HNSCC, a group that includes the most common cancers of the mouth and throat.

Led by researchers at NYU Langone Health and its Perlmutter Cancer Center, the new analyses looked at the genetic makeup of oral microbes collected from healthy men and women. Of the hundreds of different bacteria that are routinely found in the mouth, 13 species were shown to either raise or lower risk of HNSCC. Overall, this group was linked to a 30 percent greater likelihood of developing the cancers. In combination with five other species that are often seen in gum disease, the overall risk was increased by 50 percent.

“Our findings offer new insight into the relationship between the oral microbiome and head and neck cancers,” said study lead author Soyoung Kwak, PhD. “These bacteria may serve as biomarkers for experts to flag those at high risk,” added Dr. Kwak, a postdoctoral fellow in the Department of Population Health and its Division of Epidemiologia at NYU Grossman School of Medicine.

“Our results offer yet another reason to keep up good oral-hygiene habits,” said study co-senior author Richard B. Hayes, DDS, MPH, PhD. “Brushing your teeth and flossing may not only help prevent periodontal disease, but also may protect against head and neck cancer,” added Dr. Hayes, a professor in the Department of Population Health and a member of Perlmutter Cancer Center.

Source: https://jamanetwork.com/journals/jamaoncology/fullarticle/2824198