Gut Microbiota in Young MS Patients Is Higher in Pro-Inflammatory Bacteria Than Usual, Study Finds

Children and adolescents with multiple sclerosis (MS) differ from others in the composition of their gut flora, with higher levels of inflammation-causing bacteria and lower levels of anti-inflammatory bacteria, according to a study from  the University of British Columbia, Canada.

The findings, supporting previous hypotheses that the composition of the gut microbial community could influence the development of neurological and autoimmune diseases, were published in the European Journal of Neurology, in a study titled “Gut microbiota in early pediatric multiple sclerosis: a case-control study.”

MS is an autoimmune disease known to be caused by both genetic and early life environmental exposures. Previous studies, particularly in animal models, suggested a role for the gut microbiota in MS, leading the authors to further explore this association.

Because adults are exposed to many external environments and to narrow its search for disease triggers, the research team analyzed the gut flora of MS patients under 18 years of age, and within two years of disease onset. In total, 18 young people were invited to participate, half of which were naive for immunomodulatory drugs (IMD).  Their gut microbiota was compared to that of 17 healthy controls of similar ages.

Results revealed that although the general diversity of the gut microbiota did not correlate with MS status, IMD exposure modified the overall diversity of the gut bacteria. The investigators found that MS patients had an enrichment in the relative abundance of the bacterial strain Desulfovibrionaceae, and a depletion in Lachnospiraceae and Ruminococcaceae bacteria, suggesting that MS involves an increase in pro-inflammatory and a decrease in anti-inflammatory gut microbiota.

Despite these findings, it remains to be addressed whether changes in gut microbiota composition play a role in the onset of the disease, or facilitate a persistent state of immune dysregulation in MS. A better understanding of how the gut bacteria composition affects MS may be helpful in identifying new drug targets.

“While these findings are preliminary, they are intriguing. We also observed some similarities between our findings and other emerging gut microbiota studies in multiple sclerosis; whether these indicate a ‘gut signature’ of multiple sclerosis or of broader autoimmune disease remains to be determined,” Professor Helen Tremlett, the study’s lead author, said in a press release. “We also found differences in the gut microbiota composition between those children taking a disease-modifying drug for their disease compared with those who were not. This finding warrants further study.”