The aim of the study is to verify the hypothesis that the microbial colonisation of the gut is changed in patients after stroke and that the gut microbiome of severely affected stroke patients differs from that of patients with only a short disruption of blood circulation in the brain (transient ischemic attack, TIA). For this, the composition of gut microbiota in stool samples will be analyzed by 454 pyrosequencing. Further, the correlation of stroke-associated changes in the microbiome with immunological parameters will be analyzed.

Inclusion Criteria:

• age: 18 and older
• ischemic cerebral infarction within the last 40 hours, anterior circulation infarct (ACA, MCA) and/or posterior circulation infarct (PCA, BA) of any severity
• patient consent or consent by a legal representative
• NIHSS > or =9 (stroke patients)
• NIHSS < 1 (for TIA patients)

Exclusion Criteria:

• intracranial hemorrhage
• preexisting dysphagia
• signs of infection upon admission (clinical/paraclinical)
• existing antibiotic therapy upon admission or within the last 2 weeks before admission
• mechanical ventilation upon admission
• participation in an interventional therapy study

patients at the rescue center, the Stroke Unit and the neurological intensive care unit of the Charité University hospital