Randomization, intervention, and evaluations
After the assessment for eligibility, randomization was conducted using random permuted blocks of the participants after they were stratified by sex (male vs female) and CSS score (≥9 vs <9) to ensure a balanced allocation of the participants in the probiotic (BB536) and placebo groups. Sachets containing lyophilized powder of The patients were assessed by 2 questionnaires: the CSS (