Probiotics Prevent Common Cold


A meta-analysis of randomized controlled trials on the preventive benefits of probiotics revealed a modest effect in common cold reduction. Published in the January 2013 issue of the Korean Journal of Family Medicine, the systematic review looked at the results of 10 different studies comparing the incidence of cold symptoms between a people taking probiotics to a control group. Study participants who were administered probiotics for a period of less than three months had an 18% decrease in the occurrence of the common cold.

Research into the preventive benefits of probiotics has increased following a Cochrane review which concluded that prophylactic use of probiotics reduced the risk of antibiotic-associated diarrhea and the incidence of necrotic enterocolitis (NEC) in children.

Probiotics represent a large class of organisms that constitute the human gut microbiome that provide beneficial services to our overall health. In addition to aiding with the digestion of food and extraction of nutrients, probiotics interface with neuroendocrine and immune cells in digestive tissue, and can directly inhibit the growth of harmful microbes in the intestinal ecosystem.

While the review confirmed only a modest reduction in the risk of contracting a cold, the authors noted that the wide array of probiotic species and dosing strengths makes it difficult to draw broad conclusions about the preventive benefits of probiotics. Other factors, such as vitamin and mineral use, could have also impacted the overall results.

One of the most interesting aspects of the study was that the risk reduction dropped off in the participants who took probiotics for a period of longer than three months. This might suggest that there is a time-limit to preventive benefits of probiotics, or simply imply that the more time that passes by, the more likely one will contract a cold, even despite preventive measures.

Probiotics continue to accrue scientific evidence for prevention of multiple conditions, including necrotic enterocolitis, diarrhea, and the common cold. But the wide variety of formulations available can make it difficult to know which one to choose. Always inform your naturopathic doctor or other qualified health practitioner with the specific details about any probiotic products you are using, so they can advise you if a change is necessary or advisable.

Journal References

AlFaleh, K., Anabrees, J., Bassler, D. and Al-Kharfi, T. (2012), Cochrane Review: Probiotics for prevention of necrotizing enterocolitis in preterm infants. Evid.-Based Child Health, 7: 1807-1854. doi: 10.1002/ebch.1881

Allen SJ, Martinez EG, Gregorio GV, Dans LF. Probiotics for treating acute infectious diarrhoea. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD003048. doi: 10.1002/14651858.CD003048.pub3

Kang EJ, Kim SY, Hwang IH, Ji YJ. The Effect of Probiotics on Prevention of Common Cold: A Meta-Analysis of Randomized Controlled Trial Studies. Korean J Fam Med. 2013 Jan; 34(1):2-10. doi: 10.4082/kjfm.2013.34.1.2

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