Understanding the Role of Mushroom Polysaccharides and Their Health Benefits

Inside the cell walls of mushrooms are a complex carbohydrate known as polysaccharides, which play a critical role in their structural integrity and biological functions. Recent studies and clinical trials have extensively examined these essential macromolecules as one of the primary health-promoting qualities of fungi. But why are mushroom polysaccharides so beneficial to our health, and how do they impact the human body?

Impact on gut health and microbiota

Polysaccharides have been found to have a significant impact on gut health due to their role as a prebiotic. These dietary fibers help feed the beneficial bacteria in the gut, such as Bifidobacteria and Lactobacilli, therefore supporting a healthy microbiome (1). When mushroom polysaccharides are digested in the stomach, their fermentation leads to the production of Short-Chain Fatty Acids (SCFAs), like acetate, propionate, and butyrate. SCFAs serve as key energy sources for colon cells and help maintain the integrity of the gut barrier while regulating inflammation and influencing the metabolism of the host. Additionally, SCFAs can modulate immune cell function, reducing the risk of inflammatory diseases. Polysaccharides go beyond supporting the microbiota, as they can also improve intestinal barrier function, leading to a reduced risk of pathogen invasion and modulating gut-associated lymphoid tissue (2). 

Immune system boost and disease prevention

Along with enhancing immune function through the gut, mushroom polysaccharides can also stimulate the activity of various immune cells like macrophages, dendritic cells, natural killer cells, and lymphocytes, enhancing the body’s defense mechanisms against pathogens and potentially malignant cells (3). Furthermore, polysaccharides can trigger the production of cytokines, which are signaling proteins that regulate immune response and enhance the production of antibodies so that the body has a higher chance of combatting infections and diseases.

Some studies have suggested that polysaccharides have antitumor effects since they activate various components of the immune system that can target cancer cells (4), (5). Extensive reports have shown that polysaccharides can prevent or delay the onset of cancer and inhibit metastasis or cell migration. As a result, researchers believe that mushroom polysaccharides could complement conventional cancer treatments such as chemotherapy or radiation to enhance their effectiveness and potentially reduce side effects by strengthening the patient’s immune system. Some countries have already begun using mushroom-derived polysaccharides as adjunct therapies. PSK (or Polysaccharide-K) is a polysaccharide extracted from the turkey tail mushroom (Trametes versicolor) that has been commonly used in conjunction with chemo since the 1970s. Likewise, Lentinan, a polysaccharide extracted from the shiitake mushroom (Lentinus edodes), is used for similar purposes in China (6).

Metabolic homeostasis

Mushroom polysaccharides have been associated with hypocholesterolemic, antilipidemic, and anti-diabetic effects. Beta-glucans, a type of polysaccharide, have shown promise in enhancing insulin sensitivity and reducing glycemic response for a more controlled release of blood sugar levels after meals.

According to a twelve-year study based in Korea, participants who regularly consumed dietary mushrooms had a significantly lowered chance of developing type 2 diabetes (7). Some research studies suggest that mushroom-derived polysaccharide ingestion leads to a decline in blood glucose levels and insulin resistance (8), (9). Other findings have demonstrated a decrease in fat accumulation, serum lipids and cholesterol, and body weight due to mushroom polysaccharide consumption (10). These results could be due to how polysaccharides influence the gut microbiota since these changes in gut microbiota composition and activity can significantly impact metabolic processes. Moreover, SCFAs have the potential to regulate gene expression and cell signaling pathways associated with metabolic homeostasis at different levels. They might also play a critical role in cholesterol metabolism by reducing its creation and helping break down the ‘bad’ cholesterol, known as LDL.

While the mechanisms behind SCFAs and their impact on cholesterol are not entirely understood yet, they are known to influence liver functions, impacting sugar production and cholesterol formation (11).

Ongoing research and potential in disease management

Further investigation will be needed to fully understand the mechanisms of action behind different polysaccharide structures since most current studies do not provide thorough and detailed insights into their chemical structures. Β-glucan is the most studied mushroom polysaccharide, but α-glucans and chitin are limited in studies (Araújo-Rodrigues et al. 2024). Understanding the chemical structure of mushroom polysaccharides would allow scientists to understand how they interact with biological systems. 

Additionally, well-organized clinical trials with more diverse populations would significantly benefit the scientific comprehension of the health advantages of mushroom polysaccharides. This research could pave the way for new opportunities in pharmaceuticals and drug development, especially considering the already promising effects polysaccharides appear to have on multiple aspects of wellness. 

References

1. Araújo-Rodrigues, Helena, Ana Sofia Sousa, João Bettencourt Relvas, Freni K. Tavaria, and Manuela Pintado. 2024. “An Overview on Mushroom Polysaccharides: Health-Promoting Properties, Prebiotic and Gut Microbiota Modulation Effects and Structure-Function Correlation.” Carbohydrate Polymers 333 (June): 121978. https://doi.org/10.1016/j.carbpol.2024.121978.
2. Chakraborty, Nilanjan, Anuron Banerjee, Anik Sarkar, Sandipta Ghosh, and Krishnendu Acharya. 2020. “Mushroom Polysaccharides: A Potent Immune-Modulator.” Biointerface Research in Applied Chemistry 11 (2): 8915–30. https://doi.org/10.33263/briac112.89158930.
3. Gibson, Glenn R., Robert Hutkins, Mary Ellen Sanders, Susan L. Prescott, Raylene A. Reimer, Seppo J. Salminen, Karen Scott, et al. 2017. “Expert Consensus Document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) Consensus Statement on the Definition and Scope of Prebiotics.” Nature Reviews Gastroenterology & Hepatology 14 (8). https://doi.org/10.1038/nrgastro.2017.75.
4. Hao, Wudi, Chenyu Hao, Chengrong Wu, Yuqing Xu, and Cuihong Jin. 2022. “Aluminum Induced Intestinal Dysfunction via Mechanical, Immune, Chemical and Biological Barriers.” Chemosphere 288 (February): 132556. https://doi.org/10.1016/j.chemosphere.2021.132556.
5. Kim, Yu-Mi, Hye Won Woo, Min-Ho Shin, Sang Baek Koh, Hyeon Chang Kim, and Mi Kyung Kim. 2024. “A Prospective Association between Dietary Mushroom Intake and the Risk of Type 2 Diabetes: The Korean Genome and Epidemiology Study-Cardiovascular Disease Association Study.” Epidemiology and Health, January, e2024017. https://doi.org/10.4178/epih.e2024017.
6. Nakahara, Daiki, Cui Nan, Koichiro Mori, Motoki Hanayama, Haruhisa Kikuchi, Shizuka Hirai, and Yukari Egashira. 2019. “Effect of Mushroom Polysaccharides from Pleurotus Eryngii on Obesity and Gut Microbiota in Mice Fed a High-Fat Diet.” European Journal of Nutrition 59 (7): 3231–44. https://doi.org/10.1007/s00394-019-02162-7.
7. PDQ Integrative, Alternative, and Complementary Therapies Editorial Board. 2002. “Medicinal Mushrooms (PDQ®): Patient Version.” PubMed. Bethesda (MD): National Cancer Institute (US). 2002. https://www.ncbi.nlm.nih.gov/books/NBK424937/.
8. Surenjav, Unursaikhan, Lina Zhang, Xiaojuan Xu, Xufeng Zhang, and Fanbo Zeng. 2006. “Effects of Molecular Structure on Antitumor Activities of (1→3)-β-d-Glucans from Different Lentinus Edodes.” Carbohydrate Polymers 63 (1): 97–104. https://doi.org/10.1016/j.carbpol.2005.08.011.
9. Wang, Miaomiao, Santad Wichienchot, Xiaowei He, Xiong Fu, Qiang Huang, and Bin Zhang. 2019. “In Vitro Colonic Fermentation of Dietary Fibers: Fermentation Rate, Short-Chain Fatty Acid Production and Changes in Microbiota.” Trends in Food Science & Technology 88 (June): 1–9. https://doi.org/10.1016/j.tifs.2019.03.005.
10. Xiao, Chun, Chunwei Jiao, Yizhen Xie, Linhui Ye, Qianqing Li, and Qingping Wu. 2021. “Grifola Frondosa GF5000 Improves Insulin Resistance by Modulation the Composition of Gut Microbiota in Diabetic Rats.” Journal of Functional Foods 77 (February): 104313. https://doi.org/10.1016/j.jff.2020.104313.
11. Yang, Rui, Yangdan Li, Shomaila Mehmood, Chenchen Yan, Yuzhe Huang, Jingjing Cai, Junqiu Ji, Wenjuan Pan, Wenna Zhang, and Yan Chen. 2020. “Polysaccharides from Armillariella Tabescens Mycelia Ameliorate Renal Damage in Type 2 Diabetic Mice.” International Journal of Biological Macromolecules 162 (November): 1682–91. https://doi.org/10.1016/j.ijbiomac.2020.08.006.