Researchers have found that more than a dozen species of bacteria that causes gum disease can result in a 50% increased chance of neck and head cancer. The JAMA Oncology study collected saliva samples of of 160,000 Americans and tracked them for 10 to 15 years. The research team found that 236 participants had been diagnosed with head or neck cancer, and compared their mouth microbes to participants who hadn't. The comparison revealed that 13 bacterial species increased cancer risk by 30%, while five bacterial species associated with gum disease increased risks by 50%. "Our results offer yet another reason to keep up good oral hygiene habits…Brushing your teeth and flossing may not only help prevent periodontal disease, but also may protect against head and neck cance,” said co-senior author Dr. Richard Hayes. The microbes have been linked to serious gum infections that can erode the jawbone or the tissue surrounding the teeth. Lead researcher Soyoung Kwak said that the research has allowed the bacteria “ to serve as biomarkers for experts to flag those at high risk”. Naturally occurring mouth fungi did not pose any increased or decreased risk, according to researchers.