Frenemies

The long-held belief that bacteria work together within the body to ensure survival may be a myth, according to researchers at the Georgia Institute of Technology.

Researchers at GIT have found that there instead of working together, many bacteria are, in fact, fairly selfish when it comes to their survival.

During a large-scale study of microbial interactions, GIT researchers found that one of the most common mouth bacteria responsible for causing acute periodontitis, Aggregatibacter actinnmycetemcomitans (Aa), had a higher survival rate when partnered with bacteria found in other places in the body, such as the colon.

This is in contrast to what happened when Aa paired with other bacteria commonly found in the mouth. When Aa and other mouth bacteria were paired together, researchers found that their behavior changed. Instead of sharing food and helping, they became more selfish and unwilling to share.

Researchers also found that many bacteria often exist peacefully in the mouth without issue, but under certain conditions and among other types of bacteria they develop into infectors.

The GIT researchers believe their research into bacteria behavior can help determine new treatments to help fight off periodontitis and other infections.

That’s a goal that has significant benefits.

‘Periodontitis is serious; it is a widespread condition, and if left untreated it can result in serious health conditions including heart disease, diabetes and Alzheimer’s disease,’ said Dr. Sean Endsley of Legends Dental in Waco, Texas.

According to the U.S. Centers for Disease Control and Prevention, about 47.2 percent of American adults have a form of periodontitis.

In adults 65 and older, the rate of periodontitis is higher.

‘It’s about 75 percent for seniors,’ Endsley said.

During the GIT study, researchers manipulated and analyzed the behavior of all of Aa’s nearly 2,100 genes through gene-tagging technology after pairing Aa with 25 other microbes. The partner bacteria came from the mouth, other body areas and the environment.

They found that the Aa bacteria, when by itself, needed a particular set of genes to survive. When Aa was exposed to other bacteria, different genes were activated.

The project also took into consideration other factors, including smoking, poor hygiene or diabetes, and how these factors can affect bacteria in the mouth, causing microbes to become defensive and attack your gum tissue.

The risk of developing periodontitis can be reduced by brushing and flossing regularly.

‘Brushing and flossing help break up the sticky plaque that houses bacteria and causes infections,’ Endsley said.

Source: Georgia Institute of Technology. ‘Acute periodontal disease bacteria love colon and dirt microbes.’ ScienceDaily. ScienceDaily, 9 September 2019.