5 Clinical 4/19 Scientists find link between mouthwash use and raised blood pressure by Dental Tribune International good signaling molecule HOUSTON, U.S.: A balanced oral microbiome can contribute to cardiovascular health by converting dietary nitrate into nitric oxide (NO), a that helps maintain normal blood pressure. Now, a new study has suggested that chlorhexidine, an antiseptic substance found in mouthwash, may kill NO- producing bacteria and raise systolic blood pressure. The researchers used 16S rRNA gene sequencing and analysis to examine whether using chlorhexidine antiseptic mouthwash twice a day for one week would change the oral bacterial communities and blood pressure levels in 26 healthy They individuals. collected samples of the participants’ saliva and tongue scrapings and measured their blood pressure at baseline as well as seven, ten and 14 days later. in systolic The results indicated that using chlorhexidine twice a day was associated with a significant increase blood pressure and that recovery from use resulted in an enhancement in nitrate-reducing bacteria on the tongue. Individuals with relatively high levels of bacterial nitrite reductases had lower resting systolic blood pressure. “The demonstration that the presence of NO-producing bacteria in the oral cavity can help maintain normal blood pressure gives us another target to help the more than 100 million Americans living with high blood pressure,” said lead researcher Dr. Nathan S. Bryan, an adjunct professor the Department in of Molecular and Human Genetics at the Baylor College of Medicine in Houston. “Two out of three patients prescribed high blood pressure medication do not have their blood pressure adequately managed,” he added. “None of the [current] drugs for management of hypertension are targeted towards these NO- producing bacteria.” According to Bryan, owing to the widespread nature of the molecule, oral bacteria may have other profound effects on human health besides regulating blood pressure. “We know one cannot be well without an adequate amount of NO circulating throughout the body. Yet, the very first thing over 200 million Americans do each day is use an antiseptic mouthwash, which destroys the ‘good bacteria’ that help to create the NO. These A recent study has suggested that proper management of the tongue microbiome might improve resting systolic blood pressure. (Photograph: Gecko Studio/Shutterstock) published online on March 1, 2019, in Frontiers in Cellular and Infection Microbiology. once thought good habits may be doing more harm than good,” he said. The study, titled “Frequency of tongue cleaning impacts the human tongue microbiome composition and enterosalivary circulation of nitrate,” was New study shows cancer-linked genetic changes in electronic cigarette users those found in e-cigarette users were identical to in smokers. Some deregulated genes found in e-cigarette users, but not in smokers, are associated with lung cancer, esophageal cancer, bladder cancer, ovarian cancer and leukemia. A recent study has suggested that molecular changes seen in e-cigarette users may serve as an early warning of a process that may eventually lead to cancer. (Photograph: Andrey_Popov/Shutterstock) by Dental Tribune International LOS ANGELES, U.S.: Despite their thriving market, electronic cigarettes may not be a harmless alternative to smoking after all. A recent study has shown that e-cigarette users develop some of the same cancer-related molecular changes in their oral tissue as cigarette smokers, adding to growing public health concern. In the study, researchers at the University of Southern California (USC) analyzed gene expression in the oral epithelial cells of 42 e-cigarette users, 24 cigarette smokers and 27 nonsmokers to test for gene alteration, as certain alterations in gene expression can lead to cancer. Both smokers and vapers displayed abnormal expression, or deregulation, in a large number of genes linked to cancer development. About 26 percent of the deregulated genes “The existing data show that e-cig vapor is not merely ‘water vapor’ as some people believe,” said senior author Dr. Ahmad Besaratinia, Associate Professor of Research Preventive Medicine at the Keck School of Medicine of USC. “Although the concentrations of most carcinogenic compounds in e-cig products are much lower than those in cigarette smoke, there is no safe level of exposure to carcinogens.” Besaratinia noted that the molecular changes seen in the study are not cancer, or even pre-cancer, but rather an early warning of a process that could potentially lead to cancer if left untreated. The scientists are planning to replicate the study with a larger group of subjects and explore the mechanisms that cause gene deregulation. They are also launching another study in which smokers will switch to e-cigarettes to see whether any changes occur in gene regulation after the switch. “For the most part, the participants are as curious as we are to know whether these products are safe,” said Besaratinia. The study, titled “Deregulation of biologically significant genes and associated molecular pathways in the oral epithelium of electronic cigarette users,” was published online in the first February 2019 issue of the International Journal of Molecular Sciences.