Langkamp-Henken B, Rowe CC, Ford AL, Christman MC, Nieves C Jr, Khouri L, Specht GJ, Girard SA, Spaiser SJ, Dahl WJ. 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. Epub 2015 Jan 21.