Children with multiple sclerosis (MS) may show a disruption in the balance of bacteria in the gut as early as two years into the disease course, suggests new findings from Dr. Helen Tremlett and Dr. Emmanuelle Waubant (University of California, San Francisco) as part of an ongoing investigation into the link between the gut microbiome and MS.

These new findings, published in BMC Neurology, provide some insight into the way that the composition of gut microbiota may influence the body’s immune response.

“Research has observed relationships between bacteria in the gut and other autoimmune diseases,” says Dr. Tremlett, “but we know very little about the gut microbiota’s relationship with immune processes in MS.”

In this study, researchers compared children who had experienced MS onset within the previous two years and a control group of children without the disease. What they found was that there were notable differences in the relationship between gut microbiota and blood immune markers in children with MS versus controls, and that this difference was measurable even early in the disease.

In children without MS, a higher gut microbiota diversity (a marker of ‘better’ health and immune tolerance) was associated with a more balanced, non-polarized immune system, with lower pro- and anti-inflammatory markers. In the children with MS, this relationship was either not observed or was reversed.

“Why these relationships were absent or reversed in MS is intriguing and requires further investigation,” says Dr. Tremlett.

Previous research from Dr. Tremlett’s collaboration with Dr. Emmanuelle Waubant’s team has demonstrated a link between gut bacteria and relapse risk in kids with MS, and builds on their earlier work demonstrating a difference in the microbiomes of children with and without the disease.

“Our hope is that a better understanding of what could be a disruption of the microbiota-immune balance may open up new avenues of inquiry, perhaps leading to the identification of a therapeutic target within the gut to benefit outcomes in those with MS,” says Dr. Tremlett.

The current study was in collaboration with colleagues at the University of California, San Francisco, led by Dr Emmanuelle Waubant. The study was funded in part by the National MS Society (USA, PI Waubant), National Institutes of Health (USA, PI Waubant) and The Race to Erase MS (PI Waubant) and the Canada Research Chair program (PI Tremlett).


Tremlett H, Fadrosh DW, Faruqi AA, Hart J, Roalstad S, Graves J, Spencer CM, Lynch S, Zamvil SS, Waubant E, on behalf of the US Network of Pediatric MS Centers. Associations between the gut microbiota and host immune markers in pediatric multiple sclerosis and controls. BMC Neurology 2016;  16:182.