Researchers published a study suggesting that gut bacteria at young age can contribute to Multiple sclerosis (MS) disease onset and progression.
In this study, published in the journal the Proceedings of the National Academy of Sciences, researchers tested mice that were engineered to have a pre-disposition for MS. Because mice would not normally develop MS, researchers used MS-associated risk genes from real patients to genetically engineer mice for this study.
At first, when the genetically modified mice were put in a sterile, germ-free environment, they did not develop MS. When exposed to a normal environment that would normally contain bacteria, the mice did develop MS-like disease and inflammation in their bowels, suggesting gut bacteria is a risk factor that triggers MS disease development.
The study showed a link between gut bacteria and MS-like disease incidence, which was more prominent at a younger age, when MS is also more prevalent. The younger mice were more prone to develop MS than the older mice. Hiwever, increase in immunological tolerance with aging suppresses disease onset after late young adulthood in mice Together, age, gut bacteria, and MS-risk genes collaboratively seem to trigger disease. This study is also the first to identify mechanisms by which gut bacteria triggers changes in the immune system that underlie MS progression.
Authors show that gut dysbiosis induces the expression of complement C3 and production of the anaphylatoxin C3a, and down-regulates the expression of the Foxp3 gene and anergy-related E3 ubiquitin ligase genes. Consequently, gut dysbiosis was able to trigger the development of encephalitogenic T cells and promote the induction of EAE during the age window of young adulthood.
"The findings could have therapeutic implications on slowing down MS progression by manipulating gut bacteria," says the author. Future research could lead to the elimination of harmful types of gut bacteria that were shown to cause MS progression, or conversely enhance beneficial bacteria that protects from disease progression. The investigators recently received NIH funding to examine their findings in MS patients.
Age and gut bacteria contribute to MS progression!
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