Inclusion Criteria:  Diagnosis of ischemic stroke with onset in past 7 days Treatment received in the Stroke Unit of the LMU University Hospital, location Großhadern  Exclusion Criteria:  Chronic immunological disease Severe gastrointestinal disease Colectomy Artificial intestinal outlet (ostomy) Liver cirrhosis, pancreatitis, gastritis, cholecystitis (or other acute gastrointestinal diseases) Chronic alcohol abuse Terminal prognosis