Early life stress aggravates disease pathogenesis in mice with experimental autoimmune encephalomyelitis: Support for a two-hit hypothesis of multiple sclerosis etiology

Lactobacillus rhamnosus ameliorates experimental autoimmune neuritis via modulation of gut microbiota and metabolites

Background

Guillain-Barre syndrome (GBS), an autoimmune disease of the peripheral nervous system, is hallmarked by demyelination and immune cellular infiltration. Experimental autoimmune neuritis (EAN), considered a GBS prototype model, has been studied for its potential therapeutic benefits from lactobacilli. This study evaluated the protective role of Lactobacillus rhamnosus GG (GG) for treatment in EAN. T cell ratio, inflammation factors, sciatic nerve pathology, intestinal permeability, and gut inflammation were assessed on day 19 post-immunization to evaluate GG's effect on EAN. Fecal metabolomics and 16s rRNA microbiome analysis were conducted to elucidate its mechanism.

Results

GG dynamically balanced CD4+/CD8+T cell ratio, reduced serum IL-1β and TNF-α expression, improved sciatic nerve demyelination and inflammation, and enhanced neurological scores during peak disease period. Intestinal mucosal damage was evident in EAN rats, with downregulated Occludin and ZO-1 and upregulated IL-1β, TNF-α, and Reg3γ. GG treatment restored intestinal mucosal integrity, upregulated Occludin and ZO-1, and downregulated IL-1, TNF-α, and Reg3γ. GG partially rectified the gut microbiota and metabolite imbalance in EAN rats.

Conclusion

GG mitigates EAN through immune response modulation and inflammation reduction via the gut microbiota and metabolites.

Adverse Childhood Experiences and the Risk of Multiple Sclerosis Development: A Review of Potential Mechanisms

Adverse childhood experiences (ACEs), such as abuse, neglect, and household dysfunction, contribute to long-term systemic toxic stress and inflammation that may last well into adulthood. Such early-life stressors have been associated with increased susceptibility to multiple sclerosis (MS) in observational studies and with the development of experimental autoimmune encephalomyelitis in animal models. In this review, we summarize the evidence for an ACE-mediated increase in MS risk, as well as the potential mechanisms for this association. ACEs dysregulate neurodevelopment, stress responses, and immune reactivity; they also alter the interplay between the immune system and neural networks. All of this may be relevant for MS risk. We further discuss how ACEs induce epigenetic changes and how the toxic stress caused by ACEs may reactivate the Epstein-Barr Virus (EBV), a key risk factor for MS. We conclude by suggesting new initiatives to obtain further insights into this topic.