Gut microbiota and probiotics: novel immune system modulators in myasthenia gravis?

Abstract

Gut microorganisms (microbiota) live in symbiosis with the host and influence human nutrition, metabolism, physiology, and immune development and function. The microbiota prevents pathogen infection to the host, and in turn the host provides a niche for survival. The alteration of gut bacteria composition (dysbiosis) could contribute to the development of immune-mediated diseases by influencing the immune system activation and driving the pro- and anti-inflammatory responses in order to promote or counteract immune reactions. Probiotics are nonpathogenic microorganisms able to interact with the gut microbiota and provide health benefits; their use has recently been exploited to dampen immunological response in several experimental models of autoimmune diseases. Here, we focus on the relationships among commensal bacteria, probiotics, and the gut, describing the main interactions occurring with the immune system and recent data supporting the clinical efficacy of probiotic administration in rheumatoid arthritis, multiple sclerosis, and myasthenia gravis (MG) animal models. The encouraging results suggest that selected strains of probiotics should be evaluated in clinical trials as adjuvant therapy to restore the disrupted tolerance in myasthenia gravis.

Fecal microbiota profile in a group of myasthenia gravis patients

“…However, the encouraging results obtained support new studies focusing also on other MG patient subgroups with different clinical presentation and biomarkers. Our results, in agreement with the hypotheses of other authors 16 , suggest the potential interest of therapies aimed at modulating the gut microbiota in the management of MG.…”

“…While the precise etiology of MG remains obscure, it is likely that the development of this disease is dependent upon environmental factors in genetic predisposed patients. The commensal bacteria that colonize the gastrointestinal tract may also play a role in the development of the MG; the confirmation of this hypothesis would support new therapeutic strategies 16 .…”

“…However, the role of the microbiota in this context, especially regarding the neuro-muscular diseases, is only barely known. Several studies have focused on autoimmune diseases such as inflammatory bowel disease (IBD), rheumatoid arthritis or multiple sclerosis but, to date, there are no data available on other pathologies such as myasthenia gravis (MG) 16 .…”

Construction and expression of recombinant uricase‑expressing genetically engineered bacteria and its application in rat model of hyperuricemia

“…An increasing number of studies investigating probiotics have been performed in recent years. Lactobacillus is one of the probiotics present in the human intestine, which can improve intestinal microenvironment, regulate immunity and promote nutrient absorption (56)(57)(58)(59). Recent studies have demonstrated that probiotics also have a role in regulating abnormal brain activity (60,61).…”

Regulatory Effect of Bacillus subtilis on Cytokines of Dendritic Cells in Grass Carp (Ctenopharyngodon Idella)

“…In order to identify the biological pathways that were active in the stimulation, a KEGG database was used to map all of the DEGs. Most enriched KEGG pathways were related to metabolism and immune responses, suggesting that Bacillus subtilis stimulus could enhance the metabolism and regulate the immune functions of gDCs, which is similar to the effect of probiotics in mammals [43,44]. It is worth noting that the cytokine–cytokine receptor pathway was significantly enriched during the stimulus.…”