The study patients are randomized before surgery to receive either synbiotics (Synbiotics group) or placebo (Control group). Equal randomization is accomplished using a computer-generated random allocation schedule. The method of allocation concealment is sequentially numbered sealed opaque envelopes technique. Both synbiotics and placebo preparations are in foil-sealed sachets stored in identical numbered containers. Both study products are white powders, identical in weight, smell, and taste. Thus, the identity of the specific product is blind to participants, support staff and investigators for the entire duration of the study period.
