Impact of Disease-Modifying Therapies on Gut-Brain Axis in Multiple Sclerosis

Investigation of type IV collagen biomarkers in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is characterized as an inflammatory neurodegenerative disease in the central nervous system (CNS), presenting with significant inter- and intra individual heterogeneity. The pathological hallmarks of active MS lesions are blood brain barrier (BBB) disruption, inflammation, and demyelination with axonal damage. Blood-based biomarkers reflecting tissue changes in immunology and/or neurobiology may reflect MS pathology and be easily accessible. The basement membrane (BM) is a specialized form of extracellular matrix (ECM), which is primarily composed of type IV collagen and modulated in inflammatory conditions.

OBJECTIVE

We hypothesized that BM biomarkers, quantifying type IV collagen fragments, could be diagnostic blood-based biomarkers in patients with MS.

METHODS

A monoclonal antibody was raised against the cleavage site of canstatin, the C-terminal of type IV collagen-alpha-2 chain, and employed in an ELISA assay. The assay was developed, technically evaluated, and evaluated in serum from patients diagnosed with MS and compared to healthy donors. The assay was named CAN. To test the role of different blood-based biomarkers of type IV collagen in MS, we evaluated the CAN biomarker together with biomarkers of type IV collagen alpha-1 (C4M), type IV collagen alpha-3 (TUM), and type IV collagen 7S domain (PROC4) in serum from patients with MS and healthy donors.

RESULTS

The type IV collagen biomarkers CAN, TUM, and PROC4 had significantly higher levels in MS patients compared to healthy donors (CAN: 7.4 ng/mL vs. 4.9 ng/mL, p = 0.0046; TUM: 2.0 ng/mL vs. 0.7 ng/mL, p < 0.0001; and PROC4: 248.4 ng/mL vs. 160.2 ng/mL, p = 0.0067). No difference were found for C4M. TUM presented the best diagnostic power with an AUC of 0.996.

CONCLUSION

These findings are exploratory and hypothesis generating, indicating type IV collagen plays a role in the basement membrane turnover found in MS lesions, and the different collagen chains have different expression levels. These findings need to be validated in larger cohorts and longitudinal studies.

Involvement of gut microbiota in multiple sclerosis-review of a new pathophysiological hypothesis and potential treatment target

Multiple sclerosis (MS) is a chronic inflammatory disease that leads to demyelination and damage to the central nervous system. It is well known, the significance of the involvement and influence of the immune system in the development and course of MS. Nowadays, more and more studies are demonstrating that an important factor that affects the action of the immune system is the gut microbiota. Changes in the composition and interrelationships in the gut microbiota have a significant impact on the course of MS. Dysbiosis affects the disease course mainly by influencing the immune system directly but also by modifying the secreted metabolites and increasing mucosal permeability. The essential metabolites affecting the course of MS are short-chain fatty acids, which alter pro- and anti-inflammatory responses in the immune system but also increase the permeability of the intestinal wall and the blood-brain barrier. Dietary modification alone can have a significant impact on MS. Based on these interactions, new treatments for MS are being developed, including probiotics administration, supplementation of bacterial metabolites, fecal microbiota transplantation, and dietary changes. Further studies may serve to develop new drugs and therapeutic approaches for MS.

The effect of multiple sclerosis therapy on gut microbiota dysbiosis: a longitudinal prospective study

Gut microbiota has complex immune functions, related to different pathologies, including multiple sclerosis (MS).This study evaluated the influence of treatments on gut microbiota in people with MS (PwMS). The research comprised 60 participants, including 39 PwMS and 21 healthy controls (HC). Among the PwMS, 20 were prescribed a disease-modifying therapy (DMT), either interferon beta1a or teriflunomide, while 19 received a combination of classical DMT and an immunoglobulin Y (IgY) supplement. For each participant, two sets of gut samples were collected: one at the study's outset and another after two months. Alpha and beta diversity analyses revealed no significant differences between groups. In comparison to the HC, the MS group exhibited an increase in Prevotella stercorea and a decrease in Faecalibacterium prausnitzii. Following treatment, individuals with MS showed enrichment in Lachnospiraceae and Streptococcus. The second sample, compared to the first one, demonstrated an increase in Bifidobacterium angulatum and a decrease in Oscillospira for individuals with MS. Gut microbiota diversity in PwMS is not significantly different to HC.However, specific taxonomic changes indicate the presence of a dysbiosis state. The use of DMTs and immunoglobulin Y supplements may contribute to alterations in microbial composition, potentially leading to the restoration of a healthier microbiome.