The bacteria that live in your intestines (called your gut microbiome) do more than digest your food; they also play a pivotal role in your immune system health.
With regards to multiple sclerosis (MS)—a disease that results from a misguided immune system attack on the brain and spinal cord—experts have found that, compared to healthy individuals, those with MS have distinct gut microbiomes. Even more, researchers have found a link between the gut bacteria in patients with MS and an increased frequency of TH17 cells, which is a type of immune system cell that plays a key role in MS pathogenesis.
The gut bacteria/immune system link suggests that the organisms thriving in your gut may play a role in your MS disease activity.
With that, many understandably wonder whether influencing their gut microbiome, through the use of probiotics, for example, could subsequently improve their MS symptoms and perhaps, even, reduce relapses and disease progression.
While the jury is still out, the results so far are promising.
In one study in the Annals of Neurology, nine participants with relapsing-remitting MS and 13 controls (healthy participants without MS) were given a probiotic twice daily by mouth for two months.
The probiotic contained the following bacteria:
Blood and stool samples from all of the participants were collected prior to starting the probiotic, after completion of the two-month probiotic treatment course, and then three months after the probiotic was discontinued.
The stool sample was used to collect evidence about the types of bacterial species that were living within the guts of the participants. The blood samples were used to determine the degree of immune system activation in the participants.
The investigators found that with probiotic administration, there was an increase in certain species of bacteria found to be depleted in patients with MS, such as Lactobacillus and Collinsela. In addition, there was a decrease in the bacteria (e.g., Akkermansia, Blautia, and Dorea) that have been found to be elevated in the guts of MS patients.
When accessing the functional abilities of the gut bacteria in the participants, investigators found a decrease in key metabolic pathways that have been reported to be increased in people with MS.
Besides the change in the composition and function of gut bacteria, the investigators found that probiotic use was associated with a decrease in the number of monocytes (an immune system cell) in the MS patients. More specifically, there was an increased expression of anti-inflammatory genes and a decreased expression of pro-inflammatory genes within these monocytes.
These findings suggest that probiotic supplementation may alter the gut microbiome and as a result, calm down the immune system—possibly even thwarting its attack on the nervous system of patients with MS, although this latter point is still speculation.
It's important to keep in mind that this is an extremely small study. Larger studies are needed to grasp the true potential benefit of probiotic use in managing MS.
Besides being a small study, keep in mind that we still do not know whether gut microbiome changes influence MS disease activity or are a consequence of having MS (think of the chicken versus egg theory). Regardless, this study gives us hope that the gut microbiome can be altered, potentially for our benefit.
In a study in Clinical Nutrition, 60 patients with MS were randomly assigned to take either a placebo capsule containing starch or a probiotic capsule containing three Lactobacillus species and one Bifidobacterium species for 12 weeks.
The participants and the investigators were both blind to who received what capsule (called a double-blind study).
To assess for disability and depression changes with probiotic supplementation, expanded disability status scale (EDSS) scores and Beck Depression Inventory (BDI) scores, respectively, were evaluated at the start of the study and 12 weeks after the placebo/probiotic capsule was started.
Compared to the placebo participants, the participants who took the probiotic had an improvement in their EDSS and depression scores.
These results suggest that, for a person living with MS, probiotics may improve their physical abilities, like walking, as well as their mental health.
This study is also small and only lasted three months. Larger and longer studies that incorporate more objective measures of MS disease activity, like magnetic resonance imaging (MRI) of the brain, are needed.
In the end, the two above studies give MS patients and their loved ones hope that altering your gut bacteria may help treat your MS, whether that's through probiotic supplementations, diet, or even vaccination.
While probiotics are generally well-tolerated and safe, it's important to only take a probiotic under the guidance of your doctor. Moreover, be sure to not substitute a probiotic for your current disease-modifying medication; rather, consider taking a probiotic as a complementary therapy.