Possible Imbalance In Gut Bacteria Could Predict Multiple Sclerosis Severity

Multiple sclerosis (MS) affects about 2.9 million people worldwide, a chronic neurological condition in which the immune system attacks the central nervous system. The severity of MS varies among individuals, and the disease can worsen over time, known as MS exacerbations.

MS is influenced by various risk factors, including genetics, smoking, vitamin D deficiency, diet, and gut health. Recent studies have pointed to the role of gut microbiomes, the communities of bacteria living in the digestive system, as potential contributors to MS development and severity.

Ashutosh K. Mangalam, PhD, an associate professor of pathology at the University of Iowa, explained to Medical News Today that environmental factors, including viral infections, sunlight exposure, and gut bacteria, play a role in MS. His team, along with others, found differences in the gut bacteria of people with MS compared to healthy individuals, though the exact bacterial composition remains unclear. Further research is necessary to determine how changes in gut bacteria affect the disease.

In a new study published in the Proceedings of the National Academy of Sciences (PNAS), Mangalam and his colleagues identified that the balance of two types of gut bacteria might predict MS severity.

The first phase of the study involved analyzing the gut microbiomes of 45 MS patients. Researchers found higher levels of Blautia, a bacterium linked to maintaining gut health and reducing inflammation, in MS patients. Conversely, the levels of Prevotella, another bacterium, were lower. Previous studies have linked Prevotella imbalance to certain diseases.

Mangalam said, “The higher presence of Blautia and the lower levels of Prevotella suggest that specific bacterial populations could be tied to MS.” He added that Blautia was once classified under a different genus but has been linked to inflammatory diseases like lupus. The reduction of Prevotella may indicate the loss of beneficial bacteria essential for gut health, further supporting the theory that an imbalance in the microbiome, known as dysbiosis, might contribute to MS.

These findings indicate that the gut microbiome plays an important role in MS. The presence of Blautia could contribute to inflammation, while Prevotella might offer protective benefits.

In the second part of the study, the researchers used a mouse model to test the effects of Blautia and Prevotella. Mice that received Blautia showed worse MS-like symptoms and increased gut inflammation compared to those given Prevotella or a control bacterium, Phocaeicola.

Additionally, the mice with Blautia had low levels of Bifidobacterium and high levels of Akkermansia, suggesting that an imbalance between these bacteria could help predict MS severity.

Mangalam explained, “Both Blautia and Akkermansia feed on the gut lining, but Blautia creates a pro-inflammatory environment, which may trigger inflammation in the brain, similar to what we see in MS.” In contrast, Bifidobacterium thrives in a non-inflammatory environment, and its reduction in MS mice suggests it may not survive well in an inflamed gut.

The team hypothesizes that the ratio of Bifidobacterium to Akkermansia might serve as a potential marker for MS and its severity.

Following the study’s findings, Medical News Today asked Mangalam whether probiotics, such as those containing Bifidobacterium, might help slow MS progression or manage symptoms. He responded cautiously, noting that while probiotics are linked to gut health, the effect on MS remains unclear.

“At this point, we haven’t tested whether introducing Bifidobacterium could reduce disease severity,” Mangalam said. However, his team found that Prevotella seemed to improve MS symptoms in their study. He suggested that rather than focusing on probiotics, a healthy, plant-based diet could better shape the gut microbiome and support overall health.

“Small dietary changes, like increasing fiber-rich fruits and vegetables, may support a more balanced microbiome,” Mangalam advised, adding that combining such a diet with probiotics could be beneficial, although evidence for this is still limited.

Barbara Giesser, MD, a neurologist and MS specialist, reviewed the study and emphasized the need for more human studies. “This research builds on previous studies about the gut microbiome’s role in MS,” she said. “However, most of the work was done in animal models, and larger studies in humans are necessary.”

Giesser also noted that the gut microbiome is highly responsive to external factors like diet and exercise, and future research could provide new recommendations for MS patients’ lifestyle choices.