Effects of Probiotics on Respiratory Tract Infections and Quality of Life in Children: A Large, Prospective, Community-Based Study.

BACKGROUND

Respiratory tract infections (RTIs) are common in children and contribute substantially to healthcare burden. Although randomized controlled trials (RCTs) have shown probiotic benefits, evidence from large-scale, real-world community settings remains limited.

OBJECTIVE

This prospective, multicenter, community-based study evaluated the effects of combined Lactobacillus rhamnosus CRL1505 and Bifidobacterium breve M-16V supplementation on respiratory and general health outcomes in children.

METHODS

In this prospective, multicenter, single-arm, community-based study without a placebo control group, 236 children aged 0-14 years with a recent history of RTIs received a 4-week probiotic course and were included in the per-protocol analysis. Symptom frequency, medical visits, and caregiver-reported quality of life (QoL) were assessed through structured questionnaires.

RESULTS

At baseline, rhinorrhea (51.7%), cough (43.2%), and allergic manifestations (47.0%) were common. After four weeks of probiotic intake, 95.34% of guardians reported that probiotic use was associated with reduced cold frequency (p < 0.001 vs null), and 94.49% observed fewer medical visits (p < 0.001). Complete symptom disappearance occurred in 22.88% of children, while 57.63% showed marked improvement. Symptom relief occurred within 1-3 days in 58.47% of cases. Quality of life improved in 97.88% of children, including better appetite/digestion (32.63%), greater energy (31.78%), and improved sleep quality (30.93%). Gastrointestinal comfort improvement was significantly higher in children <3 years (p = 0.039). No discontinuations due to adverse events were reported. Product palatability was rated "Excellent" or "Good" by 83.05% of respondents, and 99.15% of caregivers were willing to recommend it.

CONCLUSION

In this large, real-world pediatric population, probiotic supplementation was associated with caregiver-reported reductions in RTI burden and improvements in daily well-being. These findings complement prior RCTs and support probiotic use in community settings as a preventive strategy.

TRIAL REGISTRATION: ChiCTR2500102509.