Has the influence of intestinal microbiota on human health been underestimated?

Three FAU working groups participate in new Germany-wide research priority

How do enterobacteria and epithelial cells, which prevent intestinal bacteria from entering the body unchecked, interact with each other? What is the influence of certain neurotransmitters on the immune system? And what role does the molecule CD101 play in controlling inflammatory immune responses? Three FAU working groups have been formed to answer these questions within a new DFG priority programme (SPP 1656) and investigate the connection between intestinal microbiota and human health.

According to new insights, intestinal microbiota play a much greater role in human health than previously known, and also protect the body from disease: using modern laboratory methods, scientists have succeeded in characterising the complex ecosystem of enterobacteria and verifying their findings using clinical patient data. Studies show that changes in intestinal microbiota are connected with the development of many widespread diseases such as obesity, depression and autoimmunity – an overreaction of the immune system, which attacks healthy tissue as part of a reaction to inflammation. Recently it was even shown that the transfer of intestinal microbiota from healthy to ill people can have a therapeutic effect.

In order to deepen these insights, the German Research Foundation (DFG) has announced a Germany-wide programme for the research of the effect of the intestinal microbiota on health called ‘Intestinal Microbiota – a Microbial Ecosystem at the Edge between Immune Homeostatis and Inflammation’. As many as three working groups from Erlangen were accepted in the highly competitive selection process for the first three-year funding period. This means that FAU will receive 1.2 million euros in funding.

Scientists led by Dr. Claudia Günther and Prof. Christoph Becker (Department of Medicine 1) examine how enterobacteria and epithelial cells interact in the intestine. Epithelial cells form a barrier for preventing bacteria from entering the body unchecked. First insights by the working groups prove that epithelial cells in the intestine also decide which bacteria species may live near them and which are resisted.

Dr. Stefan Wirtz and Prof. Markus Neurath (Department of Medicine 1) and their teams examine what influence certain neurotransmitters of the immune system, the interleukins, have on the interaction of the body with the intestinal microbiota. According to the researchers’ initial findings, they play a crucial role in defending the intestines from infection – for instance against salmonella;however, they are also likely to be involved significantly in the development of inflammatory bowel disease.

The project of the working group led by Prof. Jochen Mattner (Institute of Microbiology) examines the influence of T lymphocytes – a certain type of human immune cells – on the development of inflammations that attack the body’s own intestinal tissue. The researchers are especially focused on identifying types of bacteria that control the activation of these T lymphocytes via cell surface molecules. First results point towards a molecule named CD101 playing an important role in this: certain bacteria can change this molecule on the surface of the T cells – and thus influence the severity of the inflammation. The working group hopes to identify clinical markers in their research that allow for quick detection of disease activity in patients with inflammatory bowel disease.

The Germany-wide programme is co-ordinated by Prof. Dirk Haller of Technische Universität München (TUM) and Prof. Ingo Autenrieth of the University of Tübingen.

Background information: Inflammatory bowel disease

The human intestine is home to approximately 100 billion bacteria – ten times more than humans have body cells. Their diversity is tremendous: about 500 different species live in various niches in the small intestine and especially in the large intestine. The researchers differentiate between bacteria which cause disease and bacteria which are conducive to healthy intestinal microbiota. Then there are the cells of the immune system that monitor the bacteria. The peaceful co-existence of the two groups is essential to many processes in the human body: if the intestinal bacteria get out of control, this can result in inflammations in various body parts which harm the tissue. Frequently the intestine itself is affected and chronic inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis occur. More than four million people worldwide are affected, and this number is rising. In order to develop new, more effective therapies against these diseases, an exact understanding of the underlying molecular processes is needed.

Further information:

Prof. Dr. Christoph Becker
Department of Medicine 1
+49 (0)9131 85 35886

Dr. Stefan Wirtz
Department of Medicine 1
+49 (0) 9131 85 35882

Prof. Dr. Jochen Mattner
Institute of Microbiology, Immunology and Hygiene
+49 (0)9131 85 23640



Addition information