Characterization of the human microbiome in the jejunum and comparison to the microbiome in the rectum and stool in order to see how the microbial communities change within the intestines.

Subjects to undergo surgery with opening of the jejunum will be sampled with sterile swabs from peritoneum and the inside of the jejunum. A swab will also be taken from the rectum.

The peritoneum is regarded as a sterile place until today. We try to either verify this, we also could find a scientific base for theories like leaky gut or other forms of bacterial migration through the intestinal wall.

Many of these patients undergo bariatric surgery. Many of them do have a dramatic change in glucose metabolism immediate after surgery. Therefore stool swabs will be taken before and 5 days after surgery.

Inclusion Criteria:

• abdominal surgery containing opening of jejunum
• singing of consent

Exclusion Criteria:

• inflammative condition (appendicitis, pancreatitis, Crohn, Colitis ulcerous, cholecystitis and similar)

Patients with obesity