Gum Disease Bacteria Cause Cancer

Researchers from Case Western Reserve University have discovered how byproducts in the form of small fatty acids from two bacteria prevalent in gum disease incite the growth of deadly Kaposi's sarcoma-related (KS) lesions and tumors in the mouth. The discovery could lead to early saliva testing for the bacteria, which, if found, could be treated and monitored for signs of cancer and before it develops into a malignancy, researchers say. "These new findings provide one of the first looks at how the periodontal bacteria create a unique microenvironment in the oral cavity that contributes to the replication the Kaposi's sarcoma Herpesvirus (KSHV) and development of KS," said Fengchun Ye, the study's lead investigator from Case Western Reserve School of Dental Medicine's Department of Biological Sciences. The discovery is described in The Journal of Virology article, "Short Chain Fatty Acids from Periodontal Pathogens Suppress HDACs, EZH2, and SUV39H1 to Promote Kaposi's Sarcoma-Associated Herpesvirus Replication." The research focuses on how the bacteria, Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn), which are associated with gum disease, contribute to cancer formation. Ye said high levels of these bacteria are found in the saliva of people with periodontal disease, and at lower levels in those with good oral health - further evidence of the link between oral and overall physical health. KS impacts a significant number of people with HIV, whose immune systems lack the ability to fight off the herpesvirus and other infections, he said. "These individual are susceptible to the cancer," Ye said. KS first appears as lesions on the surface of the mouth that, if not removed, can grow into malignant tumors. Survival rates are higher when detected and treated early in the lesion state than when a malignancy develops. Also at risk are people with compromised immune systems: people on medications to suppress rejection of transplants, cancer patients on chemotherapies and the elderly population whose immune systems naturally weaken with age. The researchers wanted to learn why most people never develop this form of cancer and what it is that protects them. The researchers recruited 21 patients, dividing them into two groups. All participants were given standard gum-disease tests. The first group of 11 participants had an average age of 50 and had severe chronic gum disease. The second group of 10 participants, whose average age was about 26, had healthy gums, practiced good oral health and showed no signs of bleeding or tooth loss from periodontal disease. The researchers also studied a saliva sample from each. Part of the saliva sample was separated into its components using a spinning centrifuge. The remaining saliva was used for DNA testing to track and identify bacteria present, and at what levels. The researchers were interested in Pg's and Fn's byproducts of lipopolysaccharide, fimbriae, proteinases and at least five different short-chain fatty acids (SCFA): butyric acid, isobutryic acid, isovaleric acid, propionic acid and acetic acid. After initially testing the byproducts, the researchers suspected that the fatty acids were involved in replicating KSHV. The researchers cleansed the fatty acids and then introduced them to cells with quiescent KSHV virus in a petri dish for monitoring the virus' reaction. After introducing SCFA, the virus began to replicate. But the researchers saw that, while the fatty acids allowed the virus to multiple, the process also set in motion a cascade of actions that also inhibited molecules in the body's immune system from stopping the growth of KSHV. "The most important thing to come out of this study is that we believe periodontal disease is a risk factor for Kaposi sarcoma tumor in HIV patients," Ye said. With that knowledge, Ye said those with HIV must be informed about the importance of good oral health and the possible consequences of overlooking that area .

New Candy Reduces Cavities

Our mouths are a delicate balance of good and bad bacteria. When we clean our teeth, the aim is to knock out cavity-causing bacteria, while allowing beneficial oral bacteria to thrive. Now, researchers have developed a sugar-free candy, which contains dead bacteria that bind to bad bacteria, potentially reducing cavities. The importance of good oral health has been emphasized by doctors for years. Poor oral health has been linked to many conditions, from Alzheimer's disease to pancreatic cancer, not to mention cardiovascular disease. To promote better oral health, a team from the Berlin-based firm Organobalance GmbH, Germany, created a new candy, which they claim reduced levels of 'bad' bacteria in study subjects' mouths. Their research was published in Probiotics and Antimicrobial Proteins. They note that after we eat, bacteria on the surface of the teeth release acid, which can dissolve the tooth enamel, leading to cavities. The most common strain of this "bad" bacteria is called Mutans streptococci. However, the researchers say that in previous studies with rats, another bacteria called Lactobacillus paracasei has been shown to reduce levels of the cavity-causing bacteria, decreasing the number of cavities in the rodents. The team, led by Christine Lang, believe that by binding with M. streptococci, the L. paracasei bacteria prevent this bad bacteria from reattaching to the teeth, causing it to get washed away by saliva. Dentists normally suggest staying away from sweets, but a newly created sugar-free bacteria-containing candy reduced levels of bad oral bacteria. In a pilot trial involving 60 subjects, Lang and her team tested whether their sugar-free candy, which contained heat-killed samples of L. paracasei DSMZ16671, reduced levels of bad oral bacteria. One-third of the subjects ate candies with 1 mg of L. paracasei, while another third ate candies with twice this amount (2 mg). The final third served as a control group and ate candies that were similar in taste but that contained no bacteria. In total, all subjects ate five candies during the 1.5-day study. They were not allowed to perform any oral hygiene activities during this time, and they were also not allowed to consume coffee, tea, wine or probiotic foods. Results showed that nearly 75% of the participants who ate candies with the good bacteria had "significantly lower" levels of Mutans streptococci in their saliva than before, compared with the control group. Additionally, the subjects who ate candy with 2 mg of L. paracasei had a reduction in bad bacteria levels after eating only one piece of candy. The researchers write: "We think it remarkable that this effect was observed after exposure to only five pieces of candy containing 1 or 2 mg of dead L. paracasei DSMZ16671 consumed in 1.5 days." They say that by using dead bacteria, they avoided problems that live bacteria might have caused. They also note that the L. paracasei does not bind with beneficial oral bacteria, which is why this is a better cavity prevention method than other probiotics. "Additionally," they add, "sugar-free candies stimulate saliva flow, a benefit to oral health."