Randomized, placebo-controlled trial (RCT) to evaluate the coadjuvant effect of probiotic strains L. plantarum CECT30292, L.plantarum CECT7484 and CECT7485 together with P. acidilactici CECT7483, taken twice daily, in children 6 months to 5 years-old with upper respiratory tract infections with pharyngitis and/or tonsillitis, as diagnosed by a physician.~Main objective is to evaluate efficacy of this probiotic in reducing fever (as per infrared thermometer, same model for all recruited subjects) and pain (as per FLACC scale [Face, Legs, Activity, Cry and Consolability]), as well to evaluate its safety. Secondary objectives include effect on cough, rhinorrhea, nasal congestion, use of concomitant medication, emergency visits, hospitalizations, schooling absences and salivary immune markers.~Probiotic intervention will last 15 days, and patients will return for follow-up visits on the last day of probiotic intervention (day 15), and well as day 30 and 60.~The study aims at enrolling and randomizing 80 children fulfilling entry criteria and living in Mexico City area (2,200m over the sea level), after parents or legal guardians sign informed consent.
Randomized, placebo-controlled trial to evaluate the coadjuvant effect of a combination of L. plantarum and P. acidilactici probiotic strains, taken twice daily, in children 6 months to 5 years-old with upper respiratory tract infections with pharyngitis and/or tonsillitis. Main objective is to evaluate efficacy of this probiotic in reducing fever and pain, as well to evaluate its safety.