On Tuesday, February 25th, the latest publication from the Kaspar Lab was published in Applied and Environmental Microbiology, an ASM Journal. The title of the publication is “A strain of Streptococcus mitis inhibits biofilm formation of caries pathogens via abundant hydrogen peroxide production”.
The study was led by Isabella Williams, a current Ohio State senior, and Jacob Tuckerman, a current D3 student within the College of Dentistry.
Other authors included Dan Peters, former lab technician, Madisen Bangs, a D1 student, Emily Williams, also a D1 student, Iris Shin, a D2 student, and Justin Kaspar.
The study originated from the finding that a strain of Streptococcus mitis, ATCC 49456, was observed to effectively inhibit the biofilm formation of caries pathogen Streptococcus mutans. The research uncovers that the source of the biofilm inhibition is due to high hydrogen peroxide production by S. mitis ATCC 49456, which was found to produce 4-5x more hydrogen peroxide than other strains tested in the study.
The study reinforces prior work from other groups that shows hydrogen peroxide production in oral commensal streptococci to be a main antagonistic factor against caries pathogens like S. mutans. In addition, select strains such as ATCC 49456 have the propensity to produce higher amounts of hydrogen peroxide than other strains, which can be a beneficial property used to combat odontopathogens. High hydrogen peroxide production may be a desirable trait in strains considered to be oral probiotic candidates, but further research is needed to determine why strains like ATCC 49456 produce higher amounts of hydrogen peroxide compared to other strains, and its potential effects on the broader microbiome.
A strain of Streptococcus mitis inhibits Streptococcus mutans biofilm formation. Figure 1 from Williams et al 2025.