The Role of Human Microbiota in Myasthenia Gravis: A Narrative Review

Abstract

Myasthenia gravis (MG) is an autoimmune neuromuscular disease characterized by fluctuating weakness of the skeletal muscles. Although antibodies against the neuromuscular junction components are recognized, the MG pathogenesis remains unclear, even if with a well-known multifactorial character. However, the perturbations of human microbiota have been recently suggested to contribute to MG pathogenesis and clinical course. Accordingly, some products derived from commensal flora have been demonstrated to have anti-inflammatory effects, while other have been shown to possess pro-inflammatory properties. In addition, patients with MG when compared with age-matched controls showed a distinctive composition in the oral and gut microbiota, with a typical increase in Streptococcus and Bacteroides and a reduction in Clostridia as well as short-chain fatty acid reduction. Moreover, restoring the gut microbiota perturbation has been evidenced after the administration of probiotics followed by an improvement of symptoms in MG cases. To highlight the role of the oral and gut microbiota in MG pathogenesis and clinical course, here, the current evidence has been summarized and reviewed.

Neuroinflammation and Neurodegenerative Diseases: How Much Do We Still Not Know?

“…However, the related molecular and cellular mechanisms are not clear. Some studies also evidence that behavioral phenotypes can be transmitted from humans to animals via transplantation/translocation of the gut microbiota [7]. This emphasizes the role of MBG alterations in ND.…”

“…MG cases compared with age-matched controls show a characteristic composition of the oral and gut microbiota, with a typical increase in Streptococcus and Bacteroides and a reduction in Clostridia, as well as a reduction in short-chain fatty acids. Moreover, it has been demonstrated that restoration of gut microbiota disorder after probiotic administration determines an improvement in symptoms in MG cases [7].…”

“…Other unconventional mechanisms related to the onset of neuroinflammation have recently emerged in the literature. Among these includes the altered relationship of the gut microbiota with the CNS, known as gut-brain microbiota (MGB) axis [7,8]. Of note also is autophagy, although the related mechanisms remain indefinable, and further investigation is necessary [9].…”

Different Levels of Therapeutic Strategies to Recover the Microbiome to Prevent/Delay Acute Lymphoblastic Leukemia (ALL) or Arrest Its Progression in Children

“…In the last decade, recent evidence has demonstrated that another crucial determinant (trigger) of the development of several diseases is microbial dysfunction or, more accurately, dysbiosis. Dysbiosis has been shown to impact the development and progression of numerous human diseases, ranging from immune diseases, cardiovascular diseases, neurodegenerative diseases, and cancer [18][19][20][21][22]. The very relevant role of microbiota and microbiome (its genome) has led to their being considered as the second system of control of the functions of all the organs and tissues of the human body after the brain.…”

Is the Myasthenia Gravis (MG) the Result of Age and Sex/Gender? A Narrative Review for Identifying Genetic and Epigenetic Biomarkers for a Differential MG Management in Old and Young Women

“…In recent years, growing literature has centered its interest on the role of the mechanisms related to aging and sex-related factors and able in modulating and impairing immune system [1][2][3][4][5][6][7][8]. This last is composed, as well recognized, by two components, the innate and clonotypic compartments, which protect the organisms by external and internal pathogens and interact with other compartments of the same organism, such as the microbiota and central nervous system (CNS) [4][5][6][7][8]. Aging, as physiological condition, impairs cognitive and physical functions, such as the activities of immune system.…”