This study should reveal differences in composition of luminal and mucosa-associated microbiome of the human gastrointestinal tract.Therefore bacterial species of different intestinal location sites (small intestine and colon) isolated of biopsies were compared to bacterial composition of stool samples. Additionally the bacterial composition of healthy persons, patients with inflammatory bowel disease and with liver disease (liver cirrhosis) will be compared to detect influence of local and systemic inflammation on microbiome.

A dysbiosis of human gut microbiome is discussed in the pathogenesis of many disorders, also including gastrointestinal (e.g. inflammatory bowel disease, IBD) or liver diseases (e.g. liver cirrhosis) . A detailed analysis of intestinal bacterial patterns might reveal important findings for understanding disease pathogenesis. Thereby many studies only analysed the luminal microbiome of stool samples, whereas mucosa-associated bacteria have possibly a greater impact on human health and immune system .

To determine the differences of luminal and mucosa-associated bacteria, stool and mucosa samples (via biopsies) will be collected. Thereby biopsies are taken of different intestinal locations (small intestine and colon) to detect variations along intestinal tract. An additional comparison of bacterial patterns in patients with chronic, local (IBD) and systemic inflammation (with liver cirrhosis) or without intestinal inflammations (healthy controls) should reveal the influence of microbiome on or by inflammation processes.

Inclusion Criteria:

• healthy volunteers with indication for cancer screening without gastrointestinal symptoms
• patients with inflammatory bowel disease (Crohn's disease and ulcerative colitis)
• patients with indication for evaluation of liver transplantation (LTX)

Exclusion Criteria:

• other gastrointestinal disease, e.g. celiac disease, gastrointestinal tumors
• antibiotic treatment within 6 weeks before gastroscopy / colonoscopy

healthy controls patients with inflammatory bowel disease patients with liver disease (liver cirrhoses) and indication for LTX-evaluation