Probiotics labels, slapped onto gut-appeasing goods from yogurt to kefir, already line our grocery dairies. But they could soon materialize in the dental care aisle, too. “Good” bacteria may prevent cavities from forming, a new paper in the journal Applied and Environmental Microbiology reports, and getting them into our bodies could be as easy as swallowing a pill.
The human mouth is a bacterial battlefield, where individual strains are locked in a war for supremacy. Under healthy conditions, these bacteria observe a tentative truce. The “bad” strains — those that clump together to form cavity-causing plaques — thrive in acidic conditions, which they create themselves by secreting acid when given the chance. What the researchers from the University of Florida figured out is a way to keep mouth pH neutral so the cavity-causing bacteria, namely Streptococcus mutans, can’t get a foothold.
Their secret weapon? Another Streptococcus bacteria. The researchers wanted to fight fire with fire, and after screening 2,000 strains that could keep the mouth’s acidity down to normal levels, they finally found one that did the trick. The previously unidentified strain, known cryptically as “A12,” is especially good at breaking down arginine and urea, two compounds naturally found in the mouth, into ammonia, a chemical that neutralizes acid.
The added bonus is that A12 appears to be programmed to occasionally seek out and kill its cavity-causing Streptococcus cousin, without provocation.
The strategy of populating the body with good bacteria to fight less desirable ones has already been adopted by gastroenterologists, who have looked to use strains found in our poop, rather than our mouths, to set our stomachs straight.
It’ll be a while before we’ll be swallowing A12 pills after our morning floss — the researchers want to find out whether bacteria with similar properties already live in the mouth — but they’re already thinking about using the bacteria’s genome as an assessment tool for figuring out who among us are naturally the most cavity prone.