A Study to Investigate the Effect of Probiotics (Limosilactobacillus Reuteri DSM 17938 and Limosilactobacillus Reuteri DSM 33633) on Symptoms of Viral Upper Respiratory Tract Infections in Children

Inclusion Criteria: * Children with symptoms of upper respiratory tract infection (coughing/fever/sneezing/runny or congested nose/pharynx pain) * Any gender * Age from 4 years to 17 years * Signing a informed consent form by at least one parent, foster parent or guardian after patient information and by children aged over 6 years * Negative Strep test Exclusion Criteria: * Use of antibiotics or probiotics in the 10 days prior to study enrolment * Use of a probiotic other than the test sample during the study * Eight or more otitis media within 12 months * Two or more bacterial sinusitis within 12 months * Two or more pneumonia episodes within 12 months * History of two or more invasive infections (meningitis, cellulitis, osteomyelitis, septicaemia) * Chronic diarrhea * Recurrent deep skin or organ abscesses * Persistent superficial candidiasis * Use of antibiotics for two months or more to treat respiratory infections within 12 months * Gastroesophageal reflux * Perennial (e.g., dust mite or mold) or current seasonal hay fever allergy * Primary or secondary ciliary dyskinesia * Congenital malformations of the respiratory tract