A Critical Review on Health Promoting Benefits of Edible Mushrooms through Gut Microbiota By Muthukumaran Jayachandran, Jianbo Xiao, and Baojun Xu A Critical Review on Health Promoting Benefits of Edible Mushrooms through Gut Microbiota - PMC (nih.gov) Clinical Question: What are the potential health-promoting benefits of edible mushrooms through their modulation of gut microbiota? Bottom Line: Edible mushrooms possess bioactive compounds, including polysaccharides and phenolic compounds that may act as prebiotics and influence the gut microbiota. These prebiotic properties have been associated with various health benefits, such as antioxidant, anti-inflammatory, anti-tumor, and immune-modulating effects. Major Points: 1. Historical Use of Mushrooms: Mushrooms have been used for both medicinal and food purposes for thousands of years, with evidence of their use in ancient civilizations for promoting general health and treating diseases. 2. Composition of Mushrooms: Mushrooms contain bioactive polysaccharides, essential amino acids, minerals, vitamins, and phenolic compounds. Their carbohydrate content, including chitin, hemicellulose, α and β-glucans, mannans, xylans, and galactans, makes them potential prebiotics. 3. Medicinal Properties: Various mushroom species like Ganoderma lucidum (Reishi), Chaga, Coriolus versicolor, and Maitake exhibit anti-inflammatory, anti-tumor, antioxidant, antiviral, and anti-microbial properties. Their bioactive compounds contribute to these beneficial effects. 4. Role as Prebiotics: Mushrooms, rich in polysaccharides, have shown potential as prebiotics that stimulate the growth of beneficial gut microbiota. They can modify the gut microbiota composition and diversity, leading to improved host health. 5. Gut Microbiota-Associated Health Benefits: Gut microbiota play a crucial role in nutrient absorption, immune system regulation, and overall health. Mushrooms have been found to positively influence gut microbiota diversity, potentially leading to a variety of health benefits. 6. Future Perspectives: Further research is needed to understand the specific mechanisms by which mushrooms modulate gut microbiota, impact host health, and potentially contribute to disease management. Additionally, studying the compatibility and risks of microbiota transplantation could be an area of interest. COMPOSITION OF MUSHROOMS: Bioactive Polysaccharides and Amino Acids: Mushrooms contain bioactive polysaccharides and essential amino acids. These compounds contribute to the medicinal properties and potential health benefits of mushrooms. Minerals: Mushrooms are rich in various minerals, including calcium, potassium, magnesium, iron, and zinc. Potassium is notably the prevailing element. Protein Content: The protein content of dry mushrooms ranges from 228 to 249 g/kg dry matter. Protein is an important constituent of mushrooms. Carbohydrates and Medicinal Properties: Carbohydrates constitute about half of the mushroom's dry matter. Carbohydrates, including immune-stimulating β glucans and other polysaccharides, play a significant role in the medicinal properties of mushrooms. Lipid Content: Mushrooms have relatively low lipid content (crude fat), typically ranging from 20 to 30 g/kg dry matter. Vitamins: Mushrooms contain various vitamins, including ascorbic acid (vitamin C), B-group vitamins such as thiamine, riboflavin, pyridoxine, and niacin. Vitamin D2 content was found to be increased in mushrooms following ultraviolet-C (UV-C) radiation. Phenolic Compounds: Phenolic acids, particularly hydroxy derivatives of benzoic acid and trans-cinnamic acid, are considered major active components in mushrooms. Phenolic compounds, such as protocatechuic, gentisic, p-hydroxybenzoic, gallic, vanillic, and syringic acids, are commonly detected in mushrooms. Antioxidant Activity: Mushrooms possess substantial antioxidant activity due to their phenolic composition, with gallic acid being highlighted as a significant contributor. This antioxidant activity contributes to the health-promoting benefits of mushrooms. Overall, this reveals that mushrooms have a varied composition, featuring polysaccharides, amino acids, minerals, vitamins, and phenolic compounds. These elements contribute to their potential health benefits, including immune stimulation, antioxidants, and metal chelation. Metal Chelating Ability: Mushrooms show strong metal chelating ability, which is linked to their phenolic composition. This property can have implications for their potential health benefits. MEDICINAL PROPERTIES OF MUSHROOMS Medicinal Properties of Mushrooms: Mushrooms have a range of medicinal properties, including antioxidant, anti-hypertensive, hypocholesterolemic, liver protection, anti-inflammatory, anti-diabetic, anti-viral, and antimicrobial activities. Ganoderma (Reishi): Ganoderma lucidum, also known as Reishi, has strong anti-inflammatory properties, enhances immune function, and is associated with longevity and mental clarity. It contains triterpenes that induce apoptosis and protect against carcinogenesis. It has anti-inflammatory effects, acts as an immunomodulator, and promotes a healthy gut microbiota. Chaga Mushroom: Chaga contains betulinic acid derivatives and melano-glucan complexes. It's traditionally used for various conditions including cancers, infections, and gastrointestinal disorders. Chaga exhibits antioxidant, anti-cancer, and gut microbiota-modulating properties. Coriolus versicolor: Coriolus versicolor is rich in polysaccharides and used in traditional medicine for cancer, AIDS, and fungal infections. It has anti-tumor, anti-metastasis, and immunomodulatory effects. Polysaccharopeptide (PSP) in Coriolus versicolor modifies gut microbiota and exhibits antioxidant activity. Maitake: Maitake (Grifola frondosa) interacts strongly with the immune system. It contains proteoglucan D-fraction that stimulates immunity and inhibits tumor cell behavior. Maitake also inhibits hepatocellular carcinoma and shows anti-cancer activity on melanoma cells. Cordyceps, another mushroom in this group, enhances metabolic efficiency and antiviral capacity. These findings highlight the diverse medicinal properties of different mushroom species and their potential benefits for human health. GUT MICROBIOTA-ASSOCIATED HEALTH BENEFITS Microbiota Composition and Function: The gut microbiota consists of trillions of microorganisms, predominantly Bacteroidetes and Firmicutes. It aids digestion of complex foods, supports the immune system, and contributes to vitamin synthesis. Diet-Microbiota Relationship: Diet significantly affects gut microbiota composition. Shifts from plant-rich to high-fat diets influence the proportions of different microbial phyla. Health Benefits: Recent research demonstrates that a healthy gut microbiota can play a protective role against conditions like non-alcoholic fatty liver disease and pneumococcal pneumonia. Microbiota Modulation: Factors like probiotics, prebiotics, and synbiotics can positively influence gut microbiota. Prebiotics, rich in oligosaccharides or polysaccharides, hold particular importance. Functions of Gut Microbiota: The microbiota contributes to nutrient metabolism, including carbohydrate and lipid metabolism, as well as the synthesis of vitamins like K and B. Drug Metabolism: Emerging research underscores the role of the gut microbiome in drug and toxicant metabolism, adding a new dimension to pharmacology and toxicology. Immune System Regulation: Gut microbiota interacts with the immune system, modulating responses. It influences T cell differentiation and activation, regulates immunity through bacterial metabolites, and involves intestinal epithelial cells in immune-microbiota interactions. This highlights how the gut microbiota’s intricate interplay with diet, immune function, metabolism, and even drug metabolism has significant implication for human health. ROLES OF MUSHROOM AS PREBIOTICS IN IMPROVING THE HOST’S HEALTH Definition of Prebiotics: Prebiotics are substances that stimulate beneficial microorganisms in the host's body, contributing to well-being. Mushrooms as Prebiotics: Mushrooms are recognized as prebiotic sources due to their polysaccharide content, including chitin, hemicellulose, glucans, and more. Health Benefits of Mushrooms: Various mushrooms exhibit health-promoting properties, influencing immune responses, inflammation, and gut flora. For instance, white button mushrooms stimulate local inflammation and microbial diversity, aiding in recovery from infections. Ganoderma lucidium (GL): GL modulates gut microbiota composition to combat obesity, inflammation, and insulin resistance in mice. GL improves gut barrier function, reduces dysbiosis, and counters obesity-related metabolic disorders. Antioxidant Effects: Mushrooms like Agaricus bisporus improve antioxidant levels and gut microbiota composition in turkey poults, leading to enhanced growth and intestinal health. Impact on Gut Microbiota: Mushroom-derived polysaccharides from Lentinula edodes and Pleurotus spp. alter gut microbiota diversity and composition, indicating potential prebiotic effects. Bifidogenic Effects: Certain mushrooms, such as Pleurotus spp., stimulate the growth of beneficial Bifidobacterium strains, exhibiting potential prebiotic properties. Future Prospects: With over 380 medicinal mushroom species, the potential for discovering more prebiotic sources remains high. Specific Mushroom Prebiotics: Lentinula edodes-derived polysaccharide (L2) impacts immune responses and gut microbiota. Phellinus linteus and Trametes versicolor also regulate gut microbiota for host health benefits. Hericium erinaceus, known as Lion's Mane, contributes to nutritional and health benefits by affecting gut microbiota. This underscores the potential of mushrooms as prebiotics with diverse benefits, including immune regulation, obesity prevention, and improved gut health through microbiota modulation. CONCLUSIONS: In conclusion, medicinal mushrooms hold promise as prebiotics to enhance gut microbiota and human health. Traditional practices recognize their healing potential. Mushroom’s ease of availability and extensive study make them valuable prebiotic sources. Gut microbiota play a vital role in digestion, immunity, and overall well-being. Future research should focus on analyzing microbiota composition, genomic changes due to mushrooms, and effects on health conditions, immune interactions, and diet influences. Microbial transplant are also promising but require further study. Overall, understanding prebiotic-induced gut microbiota could revolutionize disease management.