Prophylactic Effect of Probiotic Streptococcus Salivarius eK12 Against Recurrent Streptococcus Pyogenes Pharyngotonsillitis Infection in Pediatrics

Inclusion Criteria: * Children aged 3-11 years. * Recent history of documented recurrent episodes of Streptococcus pyogenes pharyngo- tonsillitis infection in the last 6 months, or 4 or more episodes in the last 12 months (S. pyogenes infection being defined as: McIsaac score with clinical score ≥ 2 plus confirmation of S. pyogenes presence with rapid throat swab (RAD) method or McIsaac score =5. * Willingness to comply with the study protocol and attend scheduled follow-up visits. * Written informed consent obtained from the parent or legal guardian. Exclusion Criteria: * Children with known allergies or hypersensitivity to probiotics or any components of the study product. * Current use of antibiotics or within the past 30 days. * Used oral colonizing probiotics in the last 6 months. * Presence of severe underlying medical conditions affecting the immune system or gastrointestinal tract. * Participation in other clinical trials involving investigational drugs or interventions. * Inability to adhere to the study requirements due to logistical or social reasons. * History of rheumatic disorders, bronchospasm, severe asthma, or allergy requiring corticosteroids. * Past tonsillectomy or an indication for adeno-tonsillectomy; or severe respiratory or systemic disorders * Individuals immunocompromised or had a condition favouring recurrent Acute Otitis Media (AOM), including severe atopy, acquired or congenital immunodeficiency, cleft palate, craniofacial abnormalities, obstructive adenoids, a chronically ruptured eardrum, sleep apnoea, or tympanostomy tubes * Children undergoing current pharmacological therapies to prevent recurrent respiratory infections. * Any other medical condition or circumstance that, in the investigator's judgment, would compromise the safety of the participant or the integrity of the study.