Winter infections - common cold, nasopharyngitis, bronchitis, and bronchiolitis in infants - are most often viral in origin (rhinovirus, adenovirus, syncytial virus).
Transmitted through the air (sneezing, coughing, contact, air), the viruses spread quickly from one individual to another.1 These infections are associated with comorbid symptoms (pain, physical and mental fatigue, etc.) that negatively impact the patient’s quality of life. They are a major cause for doctor’s visits and missed school for young patients, and also lead to the inappropriate prescription of antibiotics that have no effect on viruses.2,3 The economic cost of winter respiratory infections is colossal: a study conducted in the United States estimated a loss of 20 billion dollars per year.4
Probiotics as a preventive measure...
Preventive measures (hand washing, use of disposable tissues, ventilation) ares crucial to avoid winter respiratory infections from spreading. The use of synbiotics also seems to have potential: for this application, a combination of Lactobacillus plantarum, Lactobacillus rhamnosus, and Bifidobacterium animalis subsp. lactis with prebiotics (short-chain fructooligosaccharides or galactooligosaccharides) have shown encouraging results.5 In newborns, probiotics (notably L. rhamnosus and B. lactis) may prevent winter infections in the first months of life.6
...and also to reduce infectious episodes
Once an infection is present, treatment is usually symptomatic. Some recent studies7-9 conducted with college students, however, have shown that using probiotics (L. rhamnosus and B. lactis, and B. bifidum) may significantly reduce the symptoms of winter respiratory infections and shorten their duration. Some potential probiotic mechanisms have already been observed: a barrier effect, an immunomodulating effect, an anti-inflammatory action (modulating the expression of interleukins, such as IL-1β , IL-8, IL-10), and an antimicrobial effect.9
1. Eccles R. An explanation for the seasonality of acute upper respiratory tract viral infections. Acta Otolaryngol 2002, 122(2) : 183-191. https://www.ncbi.nlm.nih.gov/pubmed/11936911
2. Linder JA & Singer DE. Health-related quality of life of adults with upper respiratory tract infections. J Gen Intern Med, 2003; 18, 802–807.
3. Nicholson KG et al. Rates of hospitalisation for influenza, respiratory syncytial virus and human metapneumovirus among infants and young children. Vaccine. 2006 Jan 9; 24(1):102-8.
4. Fendrick AM. Et al. The economic burden of non-influenza-related viral respiratory tract infection in the United States. Archives of Internal Medicine, 2003;163:487-94. http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/215118
5. Pregliasco F. et al. A new chance of preventing winter diseases by the administration of synbiotic formulations. J Clin Gastroenterol. 2008 Sep;42 Suppl 3 Pt 2:S224-33. https://www.ncbi.nlm.nih.gov/pubmed/18685511
6. Rautava S. et al. Specific probiotics in reducing the risk of acute infections in infancy--a randomised, double-blind, placebo-controlled study. Br J Nutr. 2009 Jun;101(11):1722-6. https://www.ncbi.nlm.nih.gov/pubmed/18986600
7. Smith TJ et al. Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections. Br J Nutr. 2013 Jun;109(11):1999-2007. https://www.ncbi.nlm.nih.gov/pubmed/23020819
8. Langkamp-Henken B. et al. Bifidobacterium bifidum R0071 results in a greater proportion of healthy days and a lower percentage of academically stressed students reporting a day of cold/flu: a randomised, double-blind, placebo-controlled study. Br J Nutr. 2015 Feb 14;113(3):426-34. https://www.ncbi.nlm.nih.gov/pubmed/25604727
9. Wang Y. et al. “Probiotics for Prevention and Treatment of Respiratory Tract Infections in Children: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” Ed. Sayed S. Daoud. Medicine 95.31 (2016): e4509. PMC. Web. 7 July 2017.