Treatment with antibiotics can easily lead to a shift in the species composition of intestinal bacteria towards pathogens. In an emergency, treatment-resistant germs are promoted, which means that the patient's symptoms such as diarrhoea and abdominal pain manifest themselves.

Normally, the epithelial cells of the intestinal wall form a dense barrier against bacteria and toxins. Under certain circumstances, e.g. when taking certain drugs or even exposed to permanent stress, the barrier can become permeable to pathogens, bacterial components and their toxins. These can enter the blood stream activating the immune system and can trigger inflammatory reactions in other organs.

Sepsis leads to the activation of immune cells such as monocytes or neutrophil granulocytes. Immune messenger substances such as cytokines and chemokines (especially IL-1, IL-6, IL-8, TNF) are released and lead to reactions in the surrounding organs. People with ulcerative colitis can suffer from the worst case: Under certain circumstances, a septic shock can occur with the following multiorgan failure. There is currently no therapy for this, often a piece of intestine will be removed. Research for successful therapies is urgently needed.

The exact mechanisms that ultimately lead to all these developments have not yet been sufficiently researched. Therefore, meaningful models are demanded. Animal models are only partially suitable because their "construction" is usually associated with a reduction of its immune system. However, precisely these influences of the immune system are of interest for Dr. Alexander Mosig`s is investigations.

Together with his team from the University Hospital in Jena, he has developed a so-called gut-liver-sepsis model on the microchip. The model consists of human intestinal tissue and liver tissue and is surrounded by immune cells. However, it is precisely these influences of the immune system that Dr Alexander Mosig is investigating.

Together with his team from the University Hospital in Jena, he has therefore developed a so-called intestinal liver sepsis model on the microchip. The model consists of human intestinal and liver tissue and is surrounded by immune cells. Due to different flow pressure ratios of two flow circuits (endothelial and epithelial), the artificial intestine is able to make peristaltic movements. The epithelial cells produce all necessary proteins in the model. Macrophages and dendritic cells were integrated whose "work" can be well studied by adding lipopolysaccharides that trigger the immune system.
In addition to cell biological investigations, oxygen, glucose content and pH can also be measured using sensors. In addition to the reactions, the permeability of the intestinal barrier, the infiltration into the liver as one of the organs and its regeneration ability can also be studied.

One of the goals is to provide a meaningful model with which drugs can be tested.