Multiple Sclerosis-Induced Neuroinflammation and Microbiome Dysbiosis Impair Intestinal Stemness and Regeneration
The gut-brain axis theory established itself as a crucial link between the environment and the central nervous system (CNS). This highlights concern in its participation of neurological disease onset, such as multiple sclerosis (MS). The widely used experimental autoimmune encephalomyelitis (EAE) model mimic MS inflammation in mice but requires emulsification in complete Freund's adjuvant (CFA), which induces immune systemic inflammation. Our study investigates how EAE and CFA affect intestinal stemness. Both EAE and CFA groups demonstrated a pro-inflammatory immune shift. Despite this, microbiome data revealed increase in Akkermansiaceae and Turicibacteraceae in EAE mice, displaying IBD-like dysbiosis. Surprisingly, CFA presented distinct microbial changes, such as reduction in Lactobacillaceae and enrichment of Lachnospiraceae, highlighting a disease-specific environment. Consistently, EAE mice exhibited mucin depletion, villi shortening, and muscolaris thinning. CFA groups showed crypt hyperplasia and SOX9 villi mislocations. To assess if these alterations are stemness intrinsic, we derived intestinal organoids, where we noticed increased proliferation in EAE-derived and accumulated luminal cellular debris in CFA-derived. As expected, CFA displayed higher LGR5 expression at early developmental stage and consequently decreased at late stage. In contrast, EAE showed enhanced SOX9 expansion. However, both groups reduced BMI1 and LYZ gene expression, indicating possible impaired regeneration and Paneth cells dysfunction due to pro-inflammatory status and dysbiosis. Our study revealed that CFA and EAE induce divergent inflammatory changes, highlighting the need for therapeutic strategies capable of discriminating between CFA-induced inflammatory responses and MS-specific dysregulation of intestinal stem cells and microbiota.