Smoking Appears to Eliminate Good Bacteria

Updated: 2/13/2020

Most people know the common dangers of smoking: lung cancer and oral cancer. But did you know that smoking can cause your body to attack your own good bacteria and, in turn, increase your risk for other oral diseases? The Ohio State University recently researched this issue and released its studies to the public. In doing this, researchers hope to bring to light yet another health reason for smokers to quit their habit.

Testing Bacteria Levels

Purnima Kumar, an assistant professor of periodontology at Ohio State, headed up the study. Her studies show that healthy mouths have a stable amount of the beneficial bacteria that protect you from many oral diseases. She also studied the mouths of people who smoke and saw that they have lower rates of the helpful bacteria. This has been shown to increase susceptibility to harmful bacteria. Research News at Ohio State quoted Kumar as saying:

“The smoker’s mouth kicks out the good bacteria, and the pathogens are called in. So they’re allowed to proliferate much more quickly than they would in a non-smoking environment.”

This typically means more work for the dentist to overcome the bacteria and treat any more serious issues that may yet occur.

To begin the experiments, they gathered groups of 15 smoking and 15 non-smoking healthy people. After giving each of them a thorough, professional teeth cleaning, researchers took swab samples from their gums at specified times during the week to look for several indicators. The first was differences in dental plaque makeup to see which bacteria were present in the two different groups, paying close attention to the body’s reaction to the bacteria. Researchers also wanted to know if the body was handling the bacteria as a threat, in which case they would find elevated amounts of cytokines (the body’s infection-fighters).

Smoking and Pathogens

Results showed that the non-smoking subjects had about the same proportion of bacteria at the end of the study as they did when they first had the cleaning with little to no cytokine presence. However, regarding the smoking subjects, Kumar said:

“By contrast, smokers start getting colonized by pathogens—bacteria that we know are harmful—within 24 hours. It takes longer for smokers to form a stable microbial community, and when they do, it’s a pathogen-rich community.”

This simply means that due to their smoking habits, their body quickly begins to kill off their own good bacteria, leaving them susceptible to disease. The smokers in the study also showed increased amounts of cytokines, which proves that the subjects’ bodies had been on the defense to prevent attacks from adverse bacteria. Kumar and her team do not know why exactly the smoking habit connects to these issues, but they have a theory: that the smoke interferes with regular communication between bacteria and the human body. They released the studies upon completion and reported their findings in the Infection and Immunity Journal.

According to the article, Kumar hopes that this study will encourage dentists to address these problems with their patients. As a practicing periodontist and professor, she personally talks to her smoking patients about this study and the dangers their habit can bring to their teeth. She believes the study indicates that dentists should take a more active role in encouraging their patients to quit smoking and providing access to resources that may help.