Belgian researchers find intestinal bacteria that can predict the possible development of MS | Sciences

Multiple sclerosis is a neurological disease whose exact cause is still unknown. Patients develop inflammation that causes damage to nerve pathways and their coverings. This can lead to symptoms such as fatigue, difficulty walking, cramping, double vision and more. An estimated 13,500 people live with MS in Belgium, and there are approximately 400 new diagnoses every year.

The course of the disease varies greatly from one patient to another. Therefore, predicting the long-term impact of the disease remains a challenge. Currently available methods, such as MRI, can only provide a limited prediction. So researchers have been looking for ways to improve predictions for some time.

It has been clear from previous research for some time that there is a link between MS and a disturbed microbiome, which is the sum of bacteria and other microorganisms in the body. However, those studies only focused on one moment in time. The new study followed MS patients for a long period of time to be able to draw long-term conclusions.

The research team, with scientists from the VIB-KU Leuven Center for Microbiology, the Department of Neuroscience at VUB/UZ Brussels and the National MS Center in Melsbruck, followed 111 MS patients for an average of 4.4 years. During that period, the team collected stool samples at regular intervals and performed neurological tests, such as walking tests and dexterity tests. This allowed the researchers to determine whether symptoms of the disease remained stable or worsened.

At the end of the study, 41% of patients showed a significant worsening of symptoms. Enterotype Bacteroide 2 (Bact2) was found in the stool samples of 43.6% of patients in that group. This is a specific composition of intestinal bacteria and is an indicator of a disturbed microbiome. In the group of MS patients whose symptoms remained stable, Bact2 was found in only 16.1%.

The study design could not determine whether there was a causal relationship and whether the presence of Bact2 was actually a cause of worsening MS symptoms. So far it has been shown that the two often occur together.

Because the presence of Bact2 in patients has remained relatively stable over the years, gut bacteria can help predict how a neurological disease will develop. “This makes the results very promising, although they still need to be validated in a larger group,” says Professor Jeroen Reiss (VIB-KU Leuven Center for Microbiology).

“The implications of this research are very important,” says Professor Marie Duhoges (VUB/UZ Brussels). “We now have new insights into the complex relationships between the immune system, the gut microbiome, and the central nervous system. If we know in advance which patients’ symptoms will worsen over the years, we can adapt our treatment accordingly at an early stage.”