The human mouth hosts hundreds of bacterial species that usually maintain a healthy balance and interact closely with the immune system. In people with multiple sclerosis (MS), this equilibrium is noticeably disrupted.
Studies analyzing saliva samples have revealed that beneficial bacteria are often reduced, while certain pro-inflammatory microbes become more abundant.
These shifts change the chemical environment in the mouth and can send altered signals to nearby immune cells.In addition, saliva from individuals with MS tends to contain lower levels of key protective molecules that help regulate oxidative stress.
When oxidative stress rises due to reduced protection, it can damage cells and heighten immune responses.
Since immune cells regularly sample the oral microbiome, ongoing exposure to this imbalanced microbial community may promote persistent immune activation.
These observations indicate that the oral cavity could play a more significant role in MS than previously recognized.
Alterations in mouth bacteria might mirror processes occurring in the central nervous system, or they could actively contribute to sustained inflammation.
Because saliva is simple and non-invasive to collect, these microbial signatures may eventually serve as biomarkers to monitor disease activity, progression, or treatment response.
While the gut microbiome has attracted far more research in MS, the oral microbiome appears to be another important and underexplored factor in the disease puzzle.
