The fascinating microbiome: “We are planet Earth for micro-organisms”
New institute at Universitätsklinikum Erlangen: the Department of Microbiome Research
When you hear the word microbiome, the chances are you will think of the gut. But the microbiome is so much more, namely the total of all microorganisms living on and in the human body. Skin, lungs or the digestive system, the mouth, throat, nose or the genital tract: they are all home to tiny living organisms such as bacteria, viruses or fungi. When the balance is correct, they are beneficial to human health. But what does the ideal microbiome look like? And what influence do quintillions of invisible organisms have on human health and disease? This is to be the focus of a new institute at Universitätsklinikum Erlangen: the Department of Microbiome Research led by Prof. Dr. Stephan P. Rosshart.
“The human body is like planet Earth for countless microorgansims. They live on and in it and need it as their host,” explains Stephan Rosshart. Conversely, the microorganisms are extremely beneficial for humans: they protect us from pathogens, support our immune system, digest what we cannot digest or produce important nutrients. “The microbiome is involved in nearly all physiological processes, meaning that it is basically also involved in virtually all diseases,” says Prof. Rosshart. “There is already proof of the impact it has on a number of diseases, for example inflammatory or degenerative diseases of the central nervous system such as multiple sclerosis and Alzheimer’s. We know that the gut-brain axis exists and that microbial substances that reduce inflammation, metabolites for example, are produced in the gut. Microorganisms also have a decisive role to play in cancer, allergies, autoimmune diseases and infectious diseases such as influenza or sepsis.” In a nutshell, whenever inflammation occurs and the immune system is triggered to respond, the microbiome is involved in one way or another.
Research into the microbiome still at the early stages
Research into the microbiome is still at the early stages. We are only just starting to understand the interactions and the optimal balance between microorganisms and the host. For example, until now there has been no conclusive scientific proof for the popular hygiene hypothesis that can be summed up as follows: the risk for allergies or autoimmune diseases increases the “cleaner” (more sterile) a society is and decreases the more “dirt” children are exposed to. Prof. Rosshart is convinced that is not as clear-cut as we are led to believe. “It is much more likely that many different aspects contribute to the situation, and we must take a much more open approach and consider any number of environmental factors, for example our processed food, the materials in our homes, the composition of the air we breathe, the climate, the microorganisms we are in contact with and much more besides. And then the question remains of how all of that interacts with our own microbiome.”
At the current time, there are only a few instances where findings in the field of microbiomics are used in treatments. One example is stool transplants. Stool from a healthy donor is transferred into the gut of a person with a severe infection with the clostridium difficile bacterium who does not respond to traditional medicines. In this instance, the healthy bacteria from the donor should help heal the damaged gut. The aim of the new department in Erlangen is therefore to gain a deeper understanding of the microbiome and its optimal properties and to derive potential treatments from their findings.
Stephan Rosshart, who moved to Erlangen from Universitätsklinikum Freiburg in January 2023, intends to base his new research department on collaboration, working closely with the departments of microbiology, virology and immunology, rheumatology, tumor research, gastroenterology and molecular neurology. “I would like to make a contribution to basic research at Friedrich-Alexander-Universität Erlangen-Nürnberg, but following the translational “from bench to bedside” approach, I would also like to carry out clinical studies with patients at Universitätsklinikum Erlangen, for example with people suffering from persistent, recurring bacterial or fungal infections,” he explains.
Prof. Rosshart works with “wildlings”, laboratory mice that have been given the natural microorganisms of wild mice. “We need a suitable model organism if we are to transfer our research results to humans. For some of our highly complex questions, neither the petri dish nor conventional laboratory mice are suitable, as laboratory mice live under extremely clean conditions, scarcely come into contact with microorganisms at all, and as a result have a fairly immature immune system. We humans, however, live in a non-sterile world, come into contact with microorganisms on a daily basis and therefore have a mature immune system,” the researcher explains. “If we want to investigate what impact the microbiome has on the immune response, inflammation, cancer, allergies and other disease processes, we need a model with microbial experience and a mature immune system, mirroring that of humans and wild mice. We can achieve this by transferring microorganisms from wild mice to laboratory mice.” Findings in the initial studies conducted by Prof. Rosshart indicate that wildlings really are closer to humans in this respect than laboratory mice. This means that they can give a more accurate prediction of human physiological processes for a number of questions.
Stephan Rosshart’s career to date
Stephan Rosshart studied biology and medicine at Albert-Ludwigs-Universität Freiburg and completed his doctoral degree in medicine there in 2010 at the Institute for Immunology. After his medical training at the Clinic for Internal Medicine II (gastroenterology, hepatology, endocrinology and infectiology) at Universitätsklinikum Freiburg, he spent six years conducting research at the National Institutes of Health (NIH) in Bethesda, USA. During this time, he developed the “Theory of natural microbiota” and came up with the idea for translational models for researching human diseases, in other words the wildlings. In 2019, he returned to Universitätsklinikum Freiburg, where he became the head of the gnotobiotic (sterile and microbially-controlled) animal facilities at the Clinic for Internal Medicine II and, within the context of the Emmy Noether program from the German Research Foundation, the Translational Microbiome Research Laboratory. Since January 2023, he has been the Head of the Department of Microbiome Research at Universitätsklinikum Erlangen.
Prof. Dr. Stephan P. Rosshart
Phone: +49 9131 85 35204