This study investigates the effect of Lactobacillus reuteri probiotic strains (ATCC PTA 5289 and DSM 17938) on symptoms of viral upper-respiratory tract infections in children.

Lactobacillus reuteri probiotic strains (ATCC PTA 5289 and DSM 17938) have been shown to significantly reduce the number of febrile days and pain severity in upper respiratory tract infections in children aged six months to 5 years. The investigator's planned study complements this earlier publication by significantly increasing the number of cases and expanding the age range studied including children from 4 to 17 years of age diagnosed with viral upper respiratory-tract infection.

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