In the mouth, smoking zaps healthy bacteria, welcomes pathogens
According to a new study, smoking causes the body to turn against its own helpful bacteria, leaving smokers more vulnerable to disease.
Despite the daily disturbance of brushing and flossing, the mouth of a healthy person contains a stable ecosystem of healthy bacteria. New research shows that the mouth of a smoker is a much more chaotic, diverse ecosystemand is much more susceptible to invasion by harmful bacteria.
As a group, smokers suffer from higher rates of oral diseases -- especially gum disease -- than do nonsmokers, which is a challenge for dentists, according to PurnimaKumar, assistant professor of periodontology at Ohio State University. She and her colleagues are involved in a multi-study investigation of the role the body's microbial communities play in preventing oral disease.
"The smoker's mouth kicks out the good bacteria, and the pathogens are called in," said Kumar. "So they're allowed to proliferate much more quickly than they would in a non-smoking environment."
The results suggest that dentists may have to offer more aggressive treatment for smokers and would have good reason to suggest quitting smoking, Kumar said.
"A few hours after you're born, bacteria start forming communities called biofilms in your mouth," said Kumar. "Your body learns to live with them, because for most people, healthy biofilms keep the bad bacteria away."
She likens a healthy biofilm to a lush, green lawn of grass. "When you change the dynamics of what goes into the lawn, like too much water or too little fertilizer," she said, "you get some of the grass dying, and weeds moving in." For smokers, the "weeds" are problem bacteria known to cause disease.
In a new study, Kumar's team looked at how these bacterial ecosystems regrow after being wiped away. For 15 healthy nonsmokers and 15 healthy smokers, the researchers took samples of oral biofilms one, two, four and seven days after professional cleaning.
The researchers were looking for two things when they swabbed subjects' gums. First, they wanted to see which bacteria were present by analyzing DNA signatures found in dental plaque. They also monitored whether the subjects' bodies were treating the bacteria as a threat. If so, the swab would show higher levels of cytokines, compounds the body produces to fight infection.
The results of the study were published in the journal Infection and Immunity.
"When you compare a smoker and nonsmoker, there's a distinct difference," said Kumar. "The first thing you notice is that the basic 'lawn,' which would normally contain thriving populations made of a just few types of helpful bacteria, is absent in smokers."
The team found that for nonsmokers, bacterial communities regain a similar balance of species to the communities that were scraped away during cleaning. Disease-associated bacteria are largely absent, and low levels of cytokines show that the body is not treating the helpful biofilms as a threat.
"By contrast," said Kumar, "smokers start getting colonized by pathogensbacteria that we know are harmfulwithin 24 hours. It takes longer for smokers to form a stable microbial community, and when they do, it's a pathogen-rich community."
Smokers also have higher levels of cytokines, indicating that the body is mounting defenses against infection. Clinically, this immune response takes the form of red, swollen gumscalled gingivitisthat can lead to the irreversible bone loss of periodontitis.
In smokers, however, the body is not just trying to fight off harmful bacteria. The types of cytokines in smokers' gum swabs showed the researchers that smokers' bodies were treating even healthy bacteria as threatening.
Although they do not yet understand the mechanisms behind these results, Kumar and her team suspect that smoking is confusing the normal communication that goes on between healthy bacterial communities and their human hosts.
Practically speaking, these findings have clear implications for patient care, according to Kumar.
"It has to drive how we treat the smoking population," she said. "They need a more aggressive form of treatment, because even after a professional cleaning, they're still at a very high risk for getting these pathogens back in their mouths right away.
"Dentists don't often talk to their patients about smoking cessation," she continued. "These results show that dentists should take a really active role in helping patients to get the support they need to quit."
For Kumar, who is a practicing periodontist as well as a teaching professor, doing research has changed how she treats her patients. "I tell them about our studies, about the bacteria and the host response, and I say, 'HeyI'm really scared for you.' Patients have been more willing to listen, and two actually quit."
Journal reference: Infection and Immunity
Provided by The Ohio State University
- Preventing bacteria from falling in with the wrong crowd could help stop gum disease Feb 08, 2012 | not rated yet | 0
- CDC: Fewer smokers go to the dentist Feb 07, 2012 | not rated yet | 0
- Smoking is a major cause of gum disease: study Apr 30, 2008 | not rated yet | 0
- Closer to an effective treatment for gum disease in smokers May 11, 2009 | not rated yet | 0
- Heart attack risk from smoking due to genetics Dec 19, 2007 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Bed sharing with parents is linked to a fivefold increased risk of sudden infant death syndrome (SIDS), even when the parents are non-smokers and the mother has not been drinking alcohol and does not use illegal drugs, according ...
Health 8 hours ago | 1.3 / 5 (3) | 0
Doctors tell people with a heart-zapping device in their chests to give up intense sports like basketball and soccer in favor of golf or bowling. But lots of patients ignore that advice—and now new research is challenging ...
Health 9 hours ago | not rated yet | 0
Little is known about the effect of physical education (PE) on child weight, but a new study from Cornell University finds that increasing the amount of time that elementary schoolchildren spent in gym class reduces the probability ...
Health 11 hours ago | not rated yet | 0
Living near a major roadway during the prenatal period is associated with an increased risk of respiratory infection developing in children by the age of 3, according to a new study from researchers in Boston.
Health 13 hours ago | not rated yet | 0
People who are consistently exposed to both wood smoke and tobacco smoke are at a greater risk for developing chronic obstructive pulmonary disease (COPD) and for experiencing more frequent and severe symptoms of the disease, ...
Health 13 hours ago | not rated yet | 0
Early-life exposure to traffic-related air pollution was significantly associated with higher hyperactivity scores at age 7, according to new research from the University of Cincinnati (UC) and Cincinnati Children's Hospital ...
3 hours ago | not rated yet | 0 |
(Medical Xpress)—A research team, led by Jeremy Barr, a biology post-doctoral fellow, unveils a new immune system that protects humans and animals from infection.
8 hours ago | 4.6 / 5 (12) | 4 |
New research suggests that a compound abundant in the Mediterranean diet takes away cancer cells' "superpower" to escape death. By altering a very specific step in gene regulation, this compound essentially re-educates cancer ...
11 hours ago | 4.8 / 5 (11) | 2 |
Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have ...
12 hours ago | 4.8 / 5 (6) | 2 |
Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons ...
12 hours ago | 5 / 5 (3) | 0 |
Bacteria resistant to the antibiotic colistin are also commonly resistant to antimicrobial substances made by the human body, according to a study in mBio, the online open-access journal of the American Society for Microb ...
3 hours ago | 5 / 5 (1) | 0