- About 2.9 million people worldwide live with multiple sclerosis (MS).
- MS disease severity can worsen over time.
- There are several risk factors for MS, including diet and gut health.
- A new study conducted in mice suggests that the ratio of two types of bacteria in the gut microbiome may be able to predict disease severity.
Around 2.9 million people globally live with multiple sclerosis (MS), a chronic neurological disorder where the body’s immune system attacks the central nervous system.
People with MS can experience different levels of disease severity. MS symptoms can also flare up, worsen, or expand over time, a phenomenon known as MS exacerbations.
There are a number of risk factors for MS, including nonmodifiable factors such as genetics, and modifiable factors like smoking, vitamin D deficiency, diet, and gut Health. The latter includes having an imbalanced gut microbiome.
Ashutosh K. Mangalam, PhD, an associate professor of pathology at the Carver College of Medicine at the University of Iowa, and clinician scientist at Iowa City VA health Care System, explained for Medical News Today that:
“There are several environmental factors that could contribute to MS, including viral infections, sunlight exposure (and vitamin D), and the bacteria in our gut, which [have] gained a lot of attention in recent years. Studies from our group, as well as others, have shown that the bacteria found in people with MS differ from those in Healthy individuals. However, the exact composition of these bacteria varies across different studies, indicating that more research is needed to understand how changes in gut bacteria might influence the disease.”
Mangalam is the lead author of a new study recently published in the journal PNAS, which found that the ratio of two types of bacteria in the gut microbiome may be able to predict disease severity in people with MS.
During the first portion of this study, researchers analyzed the gut microbiomes of 45 people with MS.
Scientists discovered that a type of bacterium called Blautia was more commonly found in study participants with MS. Previous research shows that Blautia helps to maintain
They also found that participants with MS had lower levels of the bacterial species Prevotella. Past studies have linked an
“The finding that Blautia is more common in multiple sclerosis (MS) patients, while Prevotella is found in lower amounts, is significant because it suggests that specific bacterial populations may be linked to the disease,” Mangalam explained.
“In our study of MS patients from the Midwest region of the U.S., we observed an enrichment of Blautia genera. This is interesting because Blautia genera was previously classified under the genus Ruminococcus, and one of its members, R. gnavus, has been associated with various inflammatory diseases like lupus,” he added.
“On the other hand, the reduction of Prevotella in MS patients might indicate a loss of beneficial bacteria that help maintain a healthy gut microbiome, further supporting the idea that dysbiosis — an imbalance in the microbiome — could play a role in MS.”
– Ashutosh K. Mangalam, PhD
“Overall, these findings suggest that the gut microbiome plays an important role in MS, with the enrichment of Blautia potentially contributing to the inflammatory processes associated with the disease, while Prevotella may offer protective benefits. Further research is needed to confirm these associations and to understand the mechanisms behind this imbalance in the microbiome,” said Mangalam.
Mangalam and his team then took their research one step further by using a mouse model where mice received either Blautia, Prevotella or, in the case of the control group, a bacterium called
Researchers observed that mice given Blautia developed more gut inflammation and worse MS-like symptoms than those that received the other types of bacteria.
Additionally, the scientists found that the Blautia mice had low levels of the bacterium Bifidobacterium and high levels of Akkermansia before their MS symptoms appeared.
Researchers believe this suggests that an imbalance between these two types of bacteria might help predict the severity of MS.
“The finding that mice given Blautia had low levels of Bifidobacterium and high levels of Akkermansia, which we also observed in MS patients, is significant because it provides further insight into how the gut microbiome may contribute to MS and inflammation,” Mangalam told us.
“Both Blautia and Akkermansia share the ability to feed on gut lining (mucin) as a food source, but they target different parts of the mucin sugar chain,” he explained. ”Blautia creates a pro-inflammatory environment by consuming one part of the mucin, leaving other parts of the mucin exposed, which can then be utilized by Akkermansia. This results in the expansion of Akkermansia and may contribute to inflammation in the gut and potentially in the brain, as seen in MS.”
“In contrast, our data also indicate that Bifidobacterium thrives in a healthy, noninflammatory environment,” continued Mangalam.
“In mice with MS-like disease, Bifidobacterium levels were reduced, suggesting that it may not survive well in an inflammatory environment. Interestingly, we found that the increase in Akkermansia levels in these mice was associated with disease. This led us to hypothesize that the ratio of Bifidobacterium to Akkermansia could serve as a potential marker for MS and its severity.”
– Ashutosh K. Mangalam, PhD
Based on this study’s findings, MNT asked Mangalam if taking probiotics and/or consuming probiotic yogurt or kefir — containing Bifidobacterium — could possibly help manage MS symptoms, or help slow down disease progression.
“While probiotics, including those containing Bifidobacterium, are often associated with gut health, we should be cautious in assuming they can help manage MS symptoms or slow disease progression,” he told us.
“At this point, we have not directly tested whether colonizing mice with Bifidobacterium reduces disease severity or alters disease progression. However, we have tested Prevotella, which appeared to ameliorate disease in our studies,” Mangalam said.
He further noted that: “It’s important to remember that autoimmune diseases like MS are akin to a civil war — where the environment within the body is not necessarily conducive to the survival of beneficial bacteria. So, even if Bifidobacterium is introduced, will it survive and exert beneficial effects in such a harsh environment? That remains an open question.”
“Rather than focusing solely on probiotics, I would recommend incorporating a healthy, plant-based diet into daily meals, as diet plays a crucial role in shaping the gut microbiome,” Mangalam advised. “I recognize that maintaining a healthy lifestyle can be particularly challenging for MS patients, but even small dietary changes — such as increasing the intake of fiber-rich fruits and vegetables — may support a more balanced microbiome.“
“Combining such a diet with probiotics might provide benefits, but at this point, we do not have direct evidence to support that claim,” he cautioned.
MNT also had the opportunity to speak with Barbara Giesser, MD, a board-certified neurologist and MS specialist at Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA, about this study.
“This study expands previous work highlighting the importance of the gut microbiome in persons with MS,” Giesser, who was not involved in the research, said. “This study suggests that the kind of bacteria and ratios of different bacteria to one another in the gut may serve as markers of disease severity.”
“Most of this work was done in the animal model and larger and longitudinal studies need to be done on humans,” she continued. “The gut microbiome is very responsive to external factors such as diet and exercise. Further work in this area may lead to more recommendations for lifestyle choices in persons with MS.”
