Multiple sclerosis (MS) is not a killer.
But this chronic inflammatory autoimmune disease of the central nervous system severely damages the communication between nerve cells in the brain and the spinal cord– leading to pain and debilitation. In essence, a protective sheath called myelin is attacked by the body’s own immune system, triggering an inflammatory response.
As with many autoimmune diseases, MS is a bit of a mystery. The cause is unknown though more than 2.3 million people worldwide live with MS. Women are three times as likely to suffer and it is most common in North America and Europe, according to the data.
Genetics increase likelihood as do environmental factors such as smoking, low vitamin D levels and diet.
Gut Microbiota in Multiple Sclerosis
MS is much more prevalent in developed countries. This fact adds credence to the hygiene hypothesis, where little exposure to oral and fecal microbes at an early age predisposes to autoimmune diseases. Hygienic practices, such as the chlorination of water, overuse of antibiotics, limited green space, small family size, and delivery by cesarean section, have resulted in changes in the microbiota.
And yes, those with MS have altered microbiomes or dysbiosis and increased intestinal permeability as well as other changes. Gut microbiota may contribute to MS pathogenesis by modulating host immunity through the regulation of multiple metabolic pathways.
The “Gut Feeling”: Breaking Down the Role of Gut Microbiome in Multiple Sclerosis published in Neurotherapeutics gives an excellent overview of the body of knowledge being explored on these pathways. In the article, the authors also discuss:
- Gut microbial differences between healthy controls and patients with MS
- Autoimmunity in MS affected by depletion or enrichment of specific gut microbes
- Reversal of dysbiosis as a therapeutic model in MS
- Roles for short chain fatty acids, bile acids, phytoestrogens, tryptophan, choline and mucin degradation
And for those readers interested in data listing microbes whose abundance is often higher or lower in patients with multiple sclerosis (MS) versus healthy controls– an excellent table is included.
Microbial Therapies in Multiple Sclerosis
A better understanding of how gut bacteria modify immune response will aid in developing therapies for treating MS. Modification of the microbiome, the use of probiotics, fecal microbiota transplantation, supplementation with bile acids and intestinal barrier enhancers are all promising candidates.
Focus on the gut-brain axis: Multiple sclerosis, the intestinal barrier and the microbiome published in World Journal of Gastroenterology in 2018 explores the trials using probiotics targeting MS in animal models and a few clinical trials. Results have shown some modest benefits but the authors concluded that study designs should be improved for more meaningful direction.
Researchers are hopeful that these promising leads will play out in tackling the scourge of MS for the millions who suffer.