Do Gut Microbes Predict Multiple Sclerosis Severity?

In a study titled Gut microbial factors predict disease severity in a mouse model of multiple sclerosis, researchers use a preclinical mouse model of multiple sclerosis to pinpoint microbial factors in the pre-disease gut microbiome that could be linked to disease outcome. Finding microbial predictors of this disease is difficult in human cohort studies, as you cannot determine whether alterations in the microbiome are a result or cause of disease. Most of these types of studies include participants who are already diagnosed with the disease or do not have the disease. It’s rare for such studies to include individuals who develop disease during the course of the research.

In contrast, a mouse model of multiple sclerosis can capture pre-disease and post-disease states in individual mice. In this study, the researchers found that Akkermansia bacteria, which are commonly associated with multiple sclerosis, have variable associations with disease in their model. This association depended on what other microbes were the microbiome. Even in mice with the same microbial composition, they found variability in disease between individual mice. This study demonstrates that connections between microbiome and disease outcomes need to consider the bi-directional interaction between host and the microbiome. The researchers found that the immunoglobulin A (IgA) coating of certain bacteria before disease is the best predictor of disease development as opposed to the abundance of specific bacteria in the gut microbiota.

Citation:

Steimle, A., et al. Gut microbial factors predict disease severity in a mouse model of multiple sclerosis. Nature microbiology, 9, 2244-2261 (2024) https://doi.org/10.1038/s41564-024-01761-3