Bacteriotherapy with Streptococcus salivarius 24SMB and Streptococcus oralis 89a nasal spray for treatment of upper respiratory tract infections in children: A pilot study on short-term efficacy

Background: Recurrent respiratory infections (RRIs) are defined by the presence of at least one of the following criteria: (i) > 6 annual respiratory infections (RIs); (ii) > 1 monthly RIs involving the upper airways from September to April; (iii) > 3 annual RIs involving the lower airways represent a very common health problem in the first years of life. We conducted a multi-centre, prospective, single-open study to assess the efficacy and the safety of Streptococcus salivarius 24SMBc and Streptococcus oralis 89a in the prevention of upper respiratory tract infections (URTIs) in children. Methods: Ninety-one children (M:F = 47:44, mean age 7.4 ± 2.3 years) with RRIs were enrolled in the study between September and November 2018. At baseline, children received Streptococcus salivarius 24SMBc and Streptococcus oralis 89a as 2 puffs for nostril twice/day for 7 days/months. The treatment lasted for 3 consecutive months. Efficacy was expressed in terms of absence or presence of fever, cough, bronchospasm, rhinorrhea and otalgia, at 1 month (T1), and 3 (T3) months. Safety and tolerability of the probiotic were evaluated on the basis of the number and type of adverse events (AEs) recorded during the treatment. Results: Children treated with Streptococcus salivarius 24SMBc and Streptococcus oralis 89a showed a significant decrease of symptoms including episodes of fever, cough, bronchospasm, rhinorrhea, and otalgia (p 0.05). Conducting a subgroup analysis according to the age, it has been reported that children aged 1-3 years old showed an improvement in all symptoms, however, they become statistically significant only at the end of the 3 months of treatment (p < 0.05). Conversely, in children aged 3-6 and 6-12 years old, the therapeutic efficacy was progressive and significant already from the first month of therapy (p < 0.05). None of the children were withdrawn from the study because of AEs, although 9 children experienced burning nose leading to interruption of therapy. Conclusions: Our findings suggest that Streptococcus salivarius 24SMBc and Streptococcus oralis 89a treatment is safe and seems to be effective on short-term in the treatment of RRIs. Studies involving a longer observation period are necessary to establish the real efficacy of the product for the treatment of pediatric patients affected by RRIs