Effect of a dietary supplement containing probiotic bacteria plus vitamins and minerals on common cold infections and cellular immune parameters.

Objective: A randomized, double-blind, placebo-controlled intervention study was carried out in order to investigate whether consumption of a dietary supplement containing probiotic bacteria plus vitamins and minerals over a period of at least three months in winter/spring affects the duration, frequency, and severity of symptoms of naturally acquired common cold infections as well as cellular immune parameters.

Methods: 477 healthy men and women (aged 36 +/- 13, mean +/- SD) who had not been vaccinated against influenza were randomly assigned to a group who received daily the probiotic multivitamin and mineral supplement (verum) or a placebo, for three (n = 239) or for 5.5 months (n = 238).