The Effects of Gut Micribiota Disruption on the Immune Response After Open Heart Surgery

Inclusion Criteria: * Age \> 18 years * Scheduled for elective on-pump cardiac surgery. * Written informed consent to participate in this trial prior to any study-mandated procedure Exclusion Criteria: * Use of any antibiotic or antifungal therapies within 30 days prior to surgery * History of inflammatory bowel disease * History of bowel resection and / or short bowel syndrome * Pre-operative creatinine clearance \< 50 ml/min * Severe hepatic impairment * Immune compromised * Solid organ transplantation * Known HIV * Pregnancy * Use of immunosuppressive drugs * Emergency surgery * Haematological disorders * Disorders from myeloid and / or lymphoid origin * Leucopenia * Known hypersensitivity to any of the investigational and/or non-investigational products or their excipients. * Treatment with investigational drugs or participation in any other intervention clinical trial within 30 days prior to study drug administration * Inability to personally provide written informed consent * Suspected of not being able to comply with the trial protocol * Use of vitamin K antagonists * Use of tricyclic antidepressants * Use of other drugs which have potential dangerous interactions with study treatment