Streptococcus salivarius K12 in pharyngotonsillitis and acute otitis media – a meta-analysis


  • Alexander Bertuccioli et al.


BLIS K12, Streptococcus salivarius K12, pharyngotonsillitis, oral probiotics


The oral administration of Streptococcus salivarius K12 represents a valid solution for the prevention of pharyngitis or pharyngotonsillitis, of bacterial or viral origin, and/or acute otitis media. In particular, this could be an interesting alternative to antibiotic prophylaxis in patients with relapse or disease recurrence. In this regard, the studies published in the scientific literature are limited, and thus, it was of interest to provide a meta-analysis in order to analyze in more detail the results obtained in this research field. For the meta-analysis, clinical studies were selected, as identified through PubMed, which examined the relationship between the use of formulations based on Streptococcus salivarius K12 and the number of cases or episodes of pharyngitis or pharyngotonsillitis, of bacterial or viral origin, and acute otitis media in children and adults. The effect size (ES) was calculated according to Cohen using the fixed effects model (fixed effects). Seven studies met the predefined inclusion criteria and they were included in the meta-analysis. ES values equal to -1.40 [-1.67; -1.13] and -1.01 [-1.19; -0.83] were obtained for the effect of Streptococcus salivarius K12 on the prevention of pharyngitis and acute otitis media, respectively. Both values were translated into a "big effect" according to Cohen's scale. Treatment based on this strain is effective for both the prevention of pharyngitis and acute otitis media. In addition, it is further revealed that the strain is more effective in the prevention of pharyngitis. It is desirable that further clinical investigation continues to expand and update the meta-analysis work and to recommend the use of the strain as a useful prophylactic tool to reduce the events of pharyngotonsillitis and acute otitis media.