Study: The gut microbiome could influence the likelihood of MS
The exact causes of MS have not yet been clarified. However, a team of German and American researchers has now succeeded for the first time in proving that the intestinal microbiome could also be a determining factor in the development of MS - alongside other triggering factors such as genetic predisposition. Even if this has only been proven in mouse experiments so far, the study provides initial evidence that in the future we will be able to intervene in the course of complex diseases such as MS through diet.
Researchers investigate: Does the gut microbiome influence MS?
Do certain intestinal bacteria increase the risk of developing MS?
The researchers examined mice with a specific genetic predisposition that makes them particularly likely to develop MS. They compared these mice with mice that were less likely to develop MS, or not at all. The intestinal microbiome of the different mouse species was also compared, i.e. the totality of all bacteria living in the intestine. It was found that one type of bacteria, Lactobacillus reuteri, was particularly common in mice with a predisposition to MS. The scientists then investigated whether the increased occurrence of these bacteria is part of the mice's genetic predisposition or whether the bacteria themselves promote MS, i.e. whether there is a causality or just a correlation. To test this, they specifically inserted Lactobacillus reuteri into the intestines of mice. A comparison group of mice received samples without this bacterium. In fact, those mice whose microbiome now had a higher proportion of Lactobacillus reuteri developed MS in greater numbers than those in the comparison group. This was the first time that it was possible to demonstrate that the composition of intestinal bacteria has an influence on the severity of MS.
Nutrition influences the gut microbiome
What is also remarkable about this study is that it also focuses on the role of nutrition in a complex disease such as MS. Ultimately, it is nutrition that influences the composition of the intestinal microbiome. However, the researchers were also surprised by the culprit they found for the development of the disease. "Due to its positive influence on digestion, Lactobacillus reuteri is often used as a probiotic. Surprisingly, in our study, this bacterium is the 'bad guy'," says the study's lead bioinformatician, Dr. Axel Künstner, in a publication by the Cluster of Excellence "Precision Medicine in Chronic Inflammation" involved in the study. This showed what an important role nutrition could play: "Our observations make it clear how important it is to take into account other factors in addition to genetics, such as the intestinal microbiome and nutrition, for the development and progression of complex diseases such as MS," Künstner continues.
What does the study mean for those affected?
Results from laboratory tests with mice are generally not transferable to humans. And it was clear to all those affected that diet is an important factor in dealing with their disease on a daily basis. As with many current studies on the subject of MS, the same applies here: the path from study results to therapies that actually help people with MS is a long one. Nevertheless, the study has added another piece to the complex mosaic of research into the causes - and the overall picture is becoming increasingly clear for researchers.
External sources
- Genetics and gut microbiome determine susceptibility to multiple sclerosis (Precision Medicine in Chronic Inflammation)
- Interactions between host genetics and gut microbiota determine susceptibility to CNS autoimmunity (Proceedings of the National Academy of Sciences of the United States of America – English source)
