This is an adaptive, parallel, double-blinded, randomized, placebo-controlled, stratified clinical study, comparing three study arms (two quantities of the probiotic active component and one placebo)with equal allocation ratio. Recruitment of subjects to the low quantity of the probiotic will be after fulfilling certain criteria at interim. After half of the subjects in the two study groups of high quantity and placebo have completed the study (40 subjects), an interim analysis will be performed. Depending on the observed effect size and the conditional power, the study may be stopped for futility, continued with the two groups or continued with inclusion of the third group of low dose probiotics.