It all started when Patrice Cani, FNRS researcher at the University of Leuven (UCLouvain) and his team repeatedly observed that a bacterium (called a subdoligranulum) is almost absent in overweight and diabetic people, while it is systematically present in healthy people. So they decided to take a closer look at this “family” of bacteria.
There is only one cultivated tribe of this family in the world (the only known member of a large family), and it is unfortunate that it is not the tribe that has been reduced in sick people. This is not uncommon: almost 70% of the bacteria in the intestine have not yet been identified (this is called the dark matter of the intestine).
In 2015, the team set about isolating the bacterium themselves in order to find out more about its effect on the human body, knowing full well that it only occurs in healthy people. For two years, the scientists searched, isolated and cultivated nearly 600 bacteria from the intestine in order to find a second family member. All in vain.
Instead, the UCLouvain team discovered a hitherto unknown bacterium of a new species. This achievement is extraordinary in itself: Very few scientists have the opportunity to discover and name a new species of bacteria in their careers. The name you chose?
Dysosmobacter welbionis. Dysosmo (“that smells bad”, in Greek), Bakter (bacterium) is the bacterium that stinks (!), “Because it has a slight smell when it is grown”. Welbionis for WELBIO, the organization in the Walloon region that funded this research.
What is special about this bacterium? It initially produces butyrate. Nothing unusual so far, many other bacteria produce this molecule, which is known to reduce the risk of colon cancer by, for example, strengthening the intestinal barrier and increasing immunity. However, the team also observed that Dysosmobacter welbionis was less present in people with type 2 diabetes.
By analyzing 12,000 fecal (microbiota) samples from around the world (ie a very representative sample of the population), UCLouvain scientists found that the bacteria are present in 70% of the population (which is very large). A surprising discovery. How is it that with such a presence it has never been discovered before? Part of the answer probably lies in the improved growing techniques developed by the UCLouvain team.
The UCLouvain team with Emilie Moens de Hase (PhD student) and Tiphaine Le Roy (postdoc) then tested the effects of Dysosmobacter welbionis on mice. The results? The bacteria increased the number of mitochondria (a kind of powerhouse in the cells that burns fat), which lowers sugar levels and weight, and they also have strong anti-inflammatory effects.
All of these effects are very promising for type 2 diabetics and obese patients and are similar to those of Akkermansia, a beneficial bacterium that is the focus of research in Patrice Canis’ laboratory.
Another observation? The effect of the bacteria is not limited to the intestines: Scientists have found that certain molecules produced by Dysosmobacter migrate through the body and also have remote effects. This is promising and probably explains the effect the bacteria have on adipose tissue, but it also opens the doors to possible influence on other diseases such as inflammation and cancer. This is currently being investigated by the team.
The next step? To test the effects of Dysosmobacter welbionis in conjunction with that of Akkermansia to see if their association can cumulate their health effects, always keeping an eye on the fight against type 2 diabetes, inflammatory diseases, obesity and cancer .
This is how research is fun: You dig for dinosaur bones and in the end you find treasure. “
Patrice Cani, FNRS researcher, University of Leuven
The originality of these discoveries? Identify a new bacterium and give it a name that will then be used worldwide: How often this has succeeded in Belgium can be counted on both fingers. But that’s not all, the same team of researchers also identified the effects of this bacterium on the body and its potential interest in fighting certain diseases.
Source:
Catholic University of Leuven
Journal reference:
Roy, TL, et al. (2021) Dysosmobacter welbionis is a newly isolated human commensal bacterium that prevents diet-related obesity and metabolic disorders in mice. Intestines. doi.org/10.1136/GUTJNL-2020-323778.
