Streptococcus salivarius K12

Safety profile

Across 4 clinical studies, no specific adverse events were reported at an increased rate compared to control. Streptococcus salivarius K12 was described as well tolerated in 3 studies, and no significant differences in safety markers or adverse event rates were observed in 4 quantitative findings. Additionally, incidences of upper respiratory infections and acute otitis media were reduced in one study, suggesting potential benefits rather than risks.

Caveats: Limited evidence base (4 studies); absence of reports does not establish safety. Most studies were likely short-term and powered for efficacy rather than safety, so rare adverse events may not have been detected.