A recent study reported significant reductions in the rate of respiratory infections in preschool children taking a combined supplement of four specific strains of probiotics with vitamin C.
Upper respiratory tract infections (URTIs) are common in children. The ProChild study is a double-blinded, randomised, placebo-controlled pilot involving 69 healthy pre-schoolers in Slovakia. For 6 months, they were given 12.5 billion colony-forming units of the Lab4 probiotic mix, containing Lactobacillus acidophilus (CUL 21 and CUL 60), Bifidobacterium bifidum (CUL 20) and Bifidobacterium animalis subsp. lactis (CUL 34), each day along with 50mg of vitamin C, or a placebo.
The treatment group had significantly reduced URTI incidences of 33% and duration of around 21 days, compared to placebo. Of the supplemented children, 35.7% suffered from 3 or more different symptoms during each infection compared to 51.7% in the placebo group. Additionally, the active group had a 30% lower preschool absence rate, fewer unscheduled visits to the paediatrician and less reliance on medications, such as antibiotics, painkillers, cough medicine or nasal spray.
The researchers concluded that this combination may be beneficial for prevention but also for reducing the severity and management of URTI symptoms.
As an individual therapy, probiotics have been shown to be better than placebo for reducing URTIs. A 2015 Cochrane review analysed 13 randomised controlled trials, looking at the use of probiotics for URTIs in all ages. Probiotics, in mixtures and single compounds, reduced the number of participants experiencing acute episodes by 47% compared to placebo, the duration of the episodes by about 1.89 days, antibiotic use and cold-related work or school absences.
This data was supported by another systematic review focusing on the effect of probiotic supplementation in preventing URTIs in a paediatric population. The summary of 14 randomised, controlled trials with high-quality methodology showed the probiotics to have benefits prophylactically with a good safety profile.
Vitamin C has also been included in many studies related to immune health and URTIs. In a 2013 Cochrane review, the authors stated that this antioxidant reduced the severity and duration of the common cold. In children, the duration was reduced by 14%, increasing to 18% when the dose was set at 1-2g.
Both probiotics and vitamin C act on the immune system, through either local immunity and/or innate and adaptive processes.
URTIs have a direct burden on the health system. For families this can mean increased medical costs, reduced access to education and parental absence from work. As URTIs are often viral, alternative strategies to antibiotics are required.
- Garaiova I, Muchova J, Nagyova Z, et al. Probiotics and vitamin C for the prevention of respiratory tract infections in children attending preschool: a randomised controlled pilot study. Eur J Clin Nutr 2015;69(3):373-379. [Full Text]
- Hao Q, Dong BR, Wu T. Probiotics for preventing acute upper respiratory tract infections. Cochrane Database Syst Rev 2015;2:CD006895. [Full Text]
- Ozen M, Kocabas Sandal G, Dinleyici EC. Probiotics for the prevention of pediatric upper respiratory tract infections: A systematic review. Expert Opin Biol Ther 2015;15(1):9-20. [Full Text]
- Hemila H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2013;1:CD000980. [Full Text]