Cigarette smoking alters the mouth microbiota

Smoking significantly changes the mouth's microbiome, with potential implications for tooth decay and the ability to break down toxins, according to results published in the ISME (International Society for Microbial Ecology) Journal.

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Smokers' mouths have lower levels of the bacteria that break down smoking-related toxins.

Cigarette smoking is the number one cause of preventable disease and mortality in the US, leading to 480,000 deaths annually, or 20% of all deaths.

Over 16 million people live with a smoking-related illness in the US, according to figures from the Centers for Disease Control and Prevention (CDC).

In 2014, the CDC estimated that 16.8% of Americans aged 18 years and over were cigarette smokers, or around 40 million adults.

Much recent research has focused on imbalances in the gut microbiota and how they relate to immune disorders such as Crohn's disease and gastrointestinal cancers.

There are around 600 species of bacteria in the human mouth. Over 75% of oral cancers are thought to be linked to smoking, but it remains unclear whether microbial differences in the mouth affect the risk for cancer.

Higher levels of Streptococcus in smokers' mouths

Researchers from New York University Langone Medical Center and its Laura and Isaac Perlmutter Cancer Center have been using precise genetic tests to investigate the impact of smoking on the composition and action of oral microbiota.

Fast facts about quitting smoking

  • In the US, there are more former smokers than current smokers, according to the CDC
  • In 2010, 68.8% of American smokers wanted to quit
  • In 2013, 48% of smokers in high school had tried to quit in the past year.

Learn more about quitting smoking

The team used mouthwash samples from 1,204 American adults who are registered in a large, ongoing study into cancer risk, funded by the National Institutes of Health (NIH) and the American Cancer Society (ACS).

Participants were all aged 50 years or over. Among them were 112 smokers and 521 individuals with no history of smoking. There were also 571 people who had quit smoking, 17% of them having stopped within the past 10 years.

Using genetic tests and statistical data, the researchers analyzed the thousands of bacteria residing in the mouths of volunteers.

Results suggest that the oral microbiome of smokers is significantly different from that of people who have never smoked or are no longer smoking. In the mouths of smokers, the levels of 150 bacterial species were significantly higher, while levels of 70 other species were distinctly lower.

Proteobacteria made up 4.6% of overall bacteria in the mouths of smokers, compared with 11.7% in nonsmokers. Proteobacteria are thought to play a part in breaking down the toxic chemicals introduced by smoking.

By contrast, 10% more species of Streptococcus were found in the mouths of smokers, compared with nonsmokers. Streptococcus is known to promote tooth decay.

Recovery comes after quitting smoking

On quitting smoking, however, the oral microbiome appears to return to its previous state. In people who had smoked previously, but not in the last 10 years, the microbial balance was the same as in the mouths of nonsmokers.

Senior investigator and epidemiologist Jiyoung Ahn, PhD, says:

"Further experiments will be needed, however, to prove that these changes weaken the body's defenses against cancer-causing chemicals in tobacco smoke, or trigger other diseases in the mouth, lungs or gut."

Co-lead investigator Brandilyn Peters, PhD, points out that the results do not reveal how long it takes former smokers' microbiome to find its balance after quitting.

The authors are planning further studies to establish the precise timeline for recovery of the bacterial community in the mouth.

They also hope to understand the biological changes that occur in the oral microbiome as a result of smoking, and how these changes might affect the risk for various cancers of the mouth and elsewhere in the body.

Medical News Today recently reported on research suggesting that the effect of some smoking cessation therapies may be limited.

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Evidence-practice gap for sealant application: Results from a dental PBRN

At the 45th Annual Meeting & Exhibition of the American Association for Dental Research, researcher Naoki Kakudate, Kyushu Dental University, Kyushu Dental University, Japan, presented a study titled "Evidence-Practice Gap for Sealant Application: Results from a Dental PBRN." The AADR Annual Meeting was held in conjunction with the 40th Annual Meeting of the Canadian Association for Dental Research.

In this study, the researchers aimed to examine dentist practice patterns regarding treatment recommendation of dental sealants and identify characteristics associated with this recommendation. The study was conducted using a cross-sectional questionnaire survey in Japan. Participants were Japanese dentists (N=282) recruited from the Japanese Dental Practice Based Research Network (JDPBRN) who indicated that they do at least some restorative dentistry. Scenarios, images and questionnaire items were the same as those used in a previous U.S. DPBRN study. A series of three clinical photographs of the occlusal surface of a mandibular first molar, together with a description, were presented portraying increasing depths of cavitation. The researchers inquired about the treatment decision for each case, which had a 12-year-old patient with high caries risk. Chi-square tests were performed to assess the association between belief about the effectiveness of caries risk assessment and sealant recommendation. Multiple logistic regression analysis were conducted to evaluate the association between the decision to recommend sealants and dentist, practice and patient characteristics.

Responses were obtained from 189 dentists (67 percent). In the hypothetical scenarios, dentists' recommendations of sealants for the 12-year old patient varied from 16 percent to 26 percent. Nineteen percent of dentists recommended sealants in the absence of dark brown pigmentation. Forty-eight percent of dentists (n=91) recommended sealants to more than 25 percent of patients ages 6-18 years. Multiple logistic regression analysis suggested that the dentist's belief in the effectiveness of caries risk assessment was significantly associated with the percentage of patients who would receive sealants. Dentist practice patterns for sealant treatment recommendation vary widely. Recommending a sealant was significantly related to the dentist having a higher belief about the effectiveness of caries risk assessment.

Recognizing Depression among Health Care Practitioners

Stress is a common occurrence in everyday lives. Whether it is running late for work because of unforeseen circumstances, trying to find time to practice healthy habits, or not being able to take a break from your hectic schedule, stressors are difficult to avoid. While some form of stress is healthy and even necessary to help us perform and react during times of crisis, prolonged and excessive stress can have damaging effects, leading to burnout or depression.

Those within the health care industry often joined their profession to find compassion and satisfaction from helping others. While that is frequently the case, it’s no surprise that at one time or another, health care professionals find themselves working under significant stress. While all health care practitioners can be at risk for burnout as a result of work, those who care for seriously ill patients face a higher risk for diminished personal wellbeing, burnout, moral distress and compassion fatigue. In addition, those caring for terminally ill patients often don’t recognize the personal emotional toll it takes, and these unexamined emotions could lead to professional loneliness, loss of professional sense of meaning, loss of clarity about the goals of medicine, cynicism, hopelessness, helplessness, frustration, anger about the health care system, loss of sense of patients as human beings, increased risk of burnout, and depression.

The problem is that depression doesn’t show up on an X-Ray or an MRI and can oftentimes be difficult to detect. So how do we know where healthy stress ends and overload begins? Every person experiences moments of sadness or struggle, however depression is more than just sadness. People with depression may experience a lack of interest and pleasure in daily activities, significant weight loss or gain, insomnia or excessive sleeping, lack of energy, inability to concentrate, feelings of worthlessness or excessive guilt and recurrent thoughts of death or suicide. As health care professionals it is critical to recognize and be aware of these symptoms, both in our personal and professional settings. Failure to recognize these symptoms could not only adversely affect your patients’ lives, but your own as well.

Fortunately, there are ways to manage stress to prevent burnout through self-care strategies. Self-care strategies begin with the recognition that people have multiple personal dimensions to attend to in order to live a good or happy life. These dimensions include family, work, community and spirituality. Strategies for personal self-care include prioritizing close relationships such as those with family; maintaining a healthy lifestyle by ensuring adequate sleep, regular exercise, and time for vacations; fostering recreational activities and hobbies; practicing mindfulness and meditation; and pursuing spiritual development. Another strategy is that of positive psychology. Positive psychology focuses on utilizing traits such as kindness, optimism, generosity, gratitude and humor. Not only will utilizing these traits lead to a happier self, they also help to build personal resilience and buffer stress.

While self-care strategies serve as important tools, it may also be helpful to meet with your primary care provider who can determine whether you can benefit from a referral to mental health specialist.