Patients with multiple sclerosis (MS) have a distinct gut microbial profile compared to healthy controls, suggesting that microbial dysbiosis may play a role in the etiology of MS.
The study, published in Scientific Reports, compared fecal microbiota from 31 patients with relapsing-remitting MS (RRMS) to 36 age- and sex-matched healthy controls.
It has been hypothesized that gastrointestinal microbiota may be a key environmental factor associated with predisposition for MS. To further examine this possibility, Jun Chen, PhD, of Mayo Clinic in Rochester, MN, and colleagues sequenced and analyzed fecal samples from 21 RRMS patients using IM_TORNADO tag sequencing of the V3-V5 region of the 16S ribosomal RNA gene.
Overall, the species richness of the RRMS gut microbiota was not significantly different than that of healthy controls, consisting of a typical Western diet diversity profile. However, upon dividing the RRMS group into active and remission groups, lower species richness was observed in patients with active disease compared to controls (P=.1). Those in remission had a similar microbiota as healthy controls. Notably, the researchers did not observe any effect of treatment status, vitamin D supplementation, or smoking on microbiota composition.
Among patients with RRMS, an abundance of Psuedomonas, Mycoplana, Haemophilus, Blautia, and Dorea genera were present, while controls showed an abundance of Parabacteroides, Adlercreutzia and Prevotella genera. Using a prediction model, the researchers found that certain genera, particularly Adlercreutzia, Pedobacter, Pseudomonas, Coprobacillus, Dorea, Flavobacterium, Parabacteroides, Mycoplana, Haemophilus, Blautia, and Collinsella, were predictive of MS disease state.
“Decreased species richness in MS patients with a recent attack compared to those in remission, and modulation of microbes associated with the induction of anti-inflammatory pathways, highlight the importance of the gut microbiome in the etiology of MS,” the authors wrote. “Based on our observations, gut microbiota may be one of the missing environmental factors responsible for the precipitation of disease in genetically susceptible individuals.”
The authors suggested that larger studies need to be conducted in order to examine the functional changes in intestinal microbiota in order to better elucidate the role of gut microbiota in modulation of the immune system.