**Probiotics Study for Respiratory Infections in Kids** This study is looking at how certain probiotics, Lactobacillus reuteri (two types: *ATCC PTA 5289* and *DSM 17938*), help children with symptoms like coughing, fever, or a runny nose from viral upper respiratory tract infections. Probiotics are helpful bacteria that can support the body's health, especially in the gut. Researchers want to see if these probiotics can reduce symptoms and make kids feel better faster. **Key Points:** - The study includes children aged 4 to 17 years with symptoms like coughing or sneezing. - Kids who have taken antibiotics or other probiotics recently cannot participate. - Participants must have a negative test for strep throat, and at least one parent or guardian must consent. The study aims to help kids with viral infections by using probiotics, but not if they have used antibiotics or have certain health conditions like frequent ear infections or allergies. If you're considering this study, think about these conditions and requirements. *Note: Always consult with your child's doctor before joining any study.*