Registered dietitian Tracey J. Smith, an adjunct professor at the University of Medicine and Dentistry of New Jersey--School of Health Related Professions, randomized 198 college students ages 18-25 living on-campus in residence halls at Framingham State University in Massachusetts.
One group received a placebo and the other group got a powder blend containing Hansen's probiotic strains Bifidobacterium animalis lactis, or BB-12, and Lactobacillus rhamnosus GG, or LGG, for 12 weeks. Each day, students completed a survey to assess the effect of the probiotic supplementation.
The study, published in the British Journal of Nutrition, found the rate of colds was similar between the two groups, but those who took the probiotics had colds two days shorter, symptoms that were 34 percent less severe and a higher quality-of-life resulted in fewer missed school days -- 15 vs. 34 missed by students taking the placebo.
"The study supports the combination of LGG and BB12 -- two very specific strains of probiotics. These two strains also are in a number of supplement-type products that are available over the counter," Smith said in a statement. "But consumers need to read the label to be sure that the product contains LGG and BB12. There also are some yogurts that contain LGG and/or BB12 but check the labels, since companies change the probiotics strains often."