Effect of administration of Streptococcus salivarius K12 on the occurrence of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media in 3 years old children.

Streptococcus salivarius K12 (BLIS K12) is a probiotic strain strongly antagonistic to the growth of Streptococcus pyogenes, the most important bacterial cause of pharyngeal infections in humans. Shown to colonize the oral cavity and to be safe for human use, BLIS K12 has previously been reported to reduce pharyngo-tonsillitis episodes in children or adults known to have experienced recurrent streptococcal infection. The present study was focussed upon evaluating the role of BLIS K12 in the control of streptococcal disease and acute otitis media in children attending the first year of kindergarten.

By randomization, 222 enrolled children attending the first year of kindergarten were divided into a treated group (N = 111) receiving for 6 months a daily treatment with BLIS K12 (Bactoblis®) and a control group (N = 111) who were monitored as untreated controls. During the 6 months of treatment and 3 months of follow-up, the children were evaluated for treatment tolerance, and for episodes of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media.

During the 6-month trial (N = 111 per group) the incidence of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media was approximately 16%, 9% and 44% respectively in the treated group and 48%, 4% and 80% in the control group. During the 3-months follow-up (N = 29 per group) the corresponding rates of infection were 15%, 0% and 12% in the treated group and 26%, 6% and 36% in the controls. No apparent side effects were detected in the treated group either during treatment or follow-up. All of the enrolled children completed the study.

The daily administration of BLIS K12 to children attending their first year of kindergarten was associated with a significant reduction in episodes of streptococcal pharyngitis and acute otitis media. No protection against scarlet fever was detected.