# Mushrooms as Functional Foods for Meniere's Disease
###### Abstract
These mushrooms are rich in non-digestible carbohydrates (e.g., chitin and glucan) and secondary metabolites (phenolic compounds, terpenoids, and lectins), which act as prebiotics and support the growth and activity of beneficial gut microbiota, thereby maintaining a healthy balance in the gut microbiome and reducing the risk of antibiotic resistance [32]. Approved for many years in Asian countries, _Ganoderma lucidum_ food components or supplements were recently given the Generally Recognized as Safe (GRAS) status and approved by the Food and Drug Administration (FDA) [33]. It is well-documented that the microbiota in the gastrointestinal tract is continuously reshaped by multiple environmental factors, especially diet, and it is decisive in human health and its balance is immunomodulated by mushroom bioactive components [34]. Nevertheless, and surprisingly, mushrooms are rarely included in most food guidelines [6]. Indeed, indigestible (by human enzymes) mushroom polysaccharides provide exceptional origin of prebiotics and curtail the reproduction of opportunistic pathogens,  
Figure 1: Ergothioneine, an antioxidant present in significant amounts in mushrooms, is an essential amino acid for humans, capable of clearing up hydroxyl radicals and maintaining bioenergetic homeostasis. promoting the growth of beneficial probiotic bacteria and restoring the bacterial imbalance in the gastrointestinal tract [35; 36]. Mushrooms polysaccharides have also been shown to enhance the antioxidant status, exercising anti-diabetic activity by lowering glycaemia and improving insulin resistance, bearing anti-intestinal inflammation and antineoplastic effects by regulating gut microbiota through improving microbiome diversity in the gut [37]. Nutrition for the increasingly susceptible aging brain has been vastly studied, and it is now well established that many dietary components play an important role in early prevention against neurodegenerative diseases. In the growing elderly population, the progressive loss of structure or function of brain neurons negatively influences the beginning, seriousness, and span of neurodegenerative diseases. Several studies on neurological impact and contributions to the growth of nerves and brain cells indicated that the presence of polyphenols in edible mushrooms demonstrated protective effects against neurodegenerative disorders and aging [38]. Very recently, mushroom components, through multiple mechanisms, were shown to have a protective role in redox homeostasis and modulated effects by hormetic nutrients in complex neurodevelopment disorders such as autism spectrum disorders [39]. Presently, the medicinal role of mushrooms in nutrient balancing, in strengthening the human immune system, in enhancing natural body resistance, and in lowering proneness to disease is well established [40]. _Coriolus versicolor_ is a type of white rot fungus found primarily on dead logs and the fungal mycelium secretes a variety of compounds into its substrate, altering its chemical composition [41]. Some mushroom bioactive elements, enzymes, and secondary metabolites have been identified and used for medicinal purposes in a purified form (Table 1) [42]. These enzymes from _Coriolus versicolor_ prevent oxidative stress (i.e., superoxide dismutase-SOD; catalase; glutathione-GSH peroxidase), inhibit cell growth (i.e., protease, glucose-2-oxidase), and play a role in detoxification (i.e., peroxid