Microbiome Research – Stool as Indicator for Diseases

The Technische Universität München, or TUM, regularly publishes its research goals and outcomes in the magazine “Faszination Forschung” (fascination research). Starting from the front page, the highlights of the most recent edition (February 2020, edition 24) make our hears beat faster, as they go: “Nutrition and Health. Dietary fiber – Why it’s essential for staying healthy. Microbiome – The ecosystem in our gut. Innovative genetics – How AI is revolutionizing plant breeding”. That’s two out of three main topics that are directly or indirectly linked to our mission. And we feel quite re-assured about that. We would especially highlight one article about Prof. Dr. Dirk Haller and his work on the human microbiome.

About Prof. Haller and his Research Focus

The article starts off explaining in detail what the human microbiome is all about. Assuming that the target group on the magazine is above all scientists, alumni, students, and employees of TUM, we can derive that even in this presumingly educated readership of academics, general awareness on the microbiome is still lacking. One tends to forget that when daily working with the matter, but the important message here is: spreading information is still essential.

Prof. Dr. Dirk Haller is head of the Chair for Nutrition and Immunology at TUM’s Weihenstephan School of Life Science. He is also spokesman for the separate field of research (SFB 1371) that the German Research Foundation (DFG) has set up: „1371 Microbiome Signatures - Funktionelle Relevanz des Mikrobioms im Verdauungstrakt“ (functional relevance of the microbiome in the gastrointestinal tract). His scientific interest in the microbiome occurred over the detour of nutritional science, as he puts it in the interview. During his research he came across the question, in how far prebiotics interact with us over our guts. At this point, the dogma of intestinal cells receiving only infectious pathogens was challenged. On the contrary, it’s mostly the harmless and even useful bacteria that influence us over our gut. What was a little revolution back then, can be sequenced by new technologies since 2005 (and that is only 15 years).

The fascinating cosmos within us, Haller is enthusiastically talking about in the interview, is probably well-known by now to our long-term readers: hundreds of species peacefully coexisting within us and interacting with us. From then on, Haller focused on finding causal links between impaired microbiome and diseases. His overall goal is to use these findings for diagnoses, prognoses, and possible therapeutic measures.

>>> Read more about "Impacts of a damage to the microbiome"

It’s in our poop – but how can we read it?

It is apparent that a person’s lifestyle is mirroring in the gut microbiome. Nevertheless, statements on the microbiome are still only general. The respective microbiome of a person is as individual as a fingerprint (meaning that a person can be clearly identified by his or her stool). Today and for 20 years now, scientists like Prof. Haller try to identify how diseases explicitly manifest in the microbiome. For that purpose, Haller has established a stock of sterile mice. That means the animals are brought up totally free of germs and are therefore especially suited for testing the gut microbiome without distorting the outcome by their individual gut composition.

For example, if a sterile mouse is transplanted the stool of an ill mouse and also falls ill, this is an important indicator for a causal link between microbial composition and disease, as genetic predispositions can be ruled out. Also, therapies in humans with fecal transplants show great success. The infection Clostridium difficile, for example, can be cured in over 90% of cases by transplanting an intact microbiome.

What diseases are we specifically talking about?

Haller and other researchers worldwide are working on understanding the interaction of microbiome and illness. What is cause, what is effect? We are talking about illnesses as dementia, autism, cirrhosis of the liver, colon cancer, Crohn’s disease, ulcerative colitis, and diabetes. That’s quite a number of diseases that occur in various parts of our body and can possibly all be changed for the better by changing our microbiome for the better.

For instance, patients suffering from type 2 diabetes were diagnosed a certain impaired circadian rhythmicity in their guts. The long-term goal of the research is to identify markers in the microbiome that are clearly linked to diabetes, in order to use these findings for prognoses. Ideally, even this is still a bit up in the air, we could end up in changing the microbiome in a way that takes away the factor that makes one prone for illnesses.

Research shows a clear correlation between Western lifestyle and increasing vulnerability for diseases as Crohn’s disease, ulcerative colitis, and diabetes. Also, obesity shows similar inflammation values that are reported with the above-mentioned diseases. Haller compares the matter with a kind of fuse that is making the whole system collapse. In some people, the collapse results in Crohn’s diseases, other suffer from obesity. The assumption is that the way of life that industrialization brings with it, is impairing the microbiome and makes the immune system more prone for several diseases.

>>> Read more about "Disorders in the digestive tract"

The weight of your “daily output” says a lot about your health

A worldwide survey on the weight of daily poop reveals that industrialized nations with nutrition poor in fiber “produce” less daily weight then nations with a traditionally fiber-rich diet. Comparing Europe with Africa, we see, for instance, a tremendously 6.5 times higher weight in Uganda (470g/d) compared to a meagre 72g/d Scotland.

This sounds very simplified and that’s what it is, indeed. A lot of research has to be done to fully understand the functionality of the microbiome and causal links to illnesses. Also, individual factors have to be drawn into account. But still, is it pretty obvious that an impaired microbiome results in dramatic illnesses up to cancer.

Haller puts his goals as follows: “After this special field of research (SFB 1371, DFG) has finished in twelve years’ time, we want to be able to answer the following question. In which diseases does the microbiome play a role, and in which not, and if it does, what precisely is that role”?