Fall Mushrooms and the Magic of Microbial Metabolism - October 2023

Fall Mushrooms and the Magic of Microbial Metabolism - October 2023

By Andrea McBeth 


As the autumn rains begin to fall in the Pacific Northwest, the forests come alive in a very special way—it's mushroom foraging season. This time of year always reminds me of another complex, often overlooked ecosystem: the human microbiome. Just as mushrooms serve as a cornerstone in our lush, forest landscapes, they also offer incredible benefits as prebiotics and postbiotics to the ecology of our gut. Inspired by a recent talk from Peter McCoy, author of "Radical Mycology," I want to pivot from the trendy topic of psychedelic mushrooms to focus on the marvelous, edible varieties. These fantastic fungi not only delight our taste buds but also play an exemplary role in supporting a healthy microbial ecosystem within us.

The Building Blocks: What are prebiotic β-glucans?

Let's start with the basics: What exactly are prebiotics, and more specifically, beta-glucans? Answering that question is not as straightforward as it may seem. The term "prebiotics" is often ambiguously defined, lacking a consensus in both marketing and scientific literature. For the purpose of this discussion, I like to think of prebiotics as molecules that bacteria can metabolize. Essentially, they are foods we consume that are not fully digested and absorbed by us, but are instead broken down by bacteria in our gut, mostly in the colon. The International Scientific Association for Probiotics and Prebiotics (ISAPP) defines prebiotics as "a substrate that is selectively utilized by host microorganisms conferring a health benefit." I find this definition less than helpful, mainly because we're still discovering the myriad health benefits that microbes and their metabolites may have on our health.

Now, with that clarified, what exactly are prebiotics? Common types include dietary fibers like inulin, fructans, glucans, oligosaccharides, and even Human Milk Oligosaccharides (HMOs) found in breast milk.(1) One subtype that has garnered particular interest is beta-glucans. These naturally occurring polysaccharides are abundant not just in mushrooms, but also in cereals like oats and barley. They've earned praise for their wide-ranging health benefits, from supporting the immune system to aiding liver function.(2,3) And I believe they serve as an excellent example of how complex, nutrient-rich foods like mushrooms can impact our health through the microbiome.

Mushrooms: A Unique Source of Beta-Glucans

You might be wondering, "If beta-glucans are also found in oats and barley, what sets mushrooms apart?" Excellent question! The key distinction lies in the complexity of molecules and unique structural fibers present in mushrooms. While oats and barley are rich in phytochemicals that confer specific health benefits like cardiovascular support, mushrooms offer an entirely different level of biochemical complexity. Mushroom-derived beta-glucans have more intricate branching patterns in their molecular structures, enabling them to interact more effectively with our gut bacteria. This structural uniqueness has been shown to trigger specific immune responses, giving mushrooms an edge in both gut health and immune function.(4)

What adds another layer to this is that fungi, including mushrooms, are much older evolutionary organisms than plants like oats and barley. This ancient lineage has given them time to develop complex molecules not found in younger plant species. The result? A variety of mushrooms each with its own set of beta-glucans and other bioactive compounds that offer a broader range of health benefits. For instance, shiitake and maitake mushrooms are recognized for their anti-inflammatory and immune-boosting effects while Reishi and Turkey Tail have been studied in cancer support.(5,6) Including these diverse fungi in your diet provides a synergistic, holistic approach to gut health, aiding digestion and reinforcing your internal microbial ecosystem. Therefore, mushrooms stand as an essential yet often overlooked component in a balanced diet aimed at nurturing a robust and resilient microbiome.

The Marvels of Metabolism: From Beta-Glucans to SCFAs

The story of beta-glucans doesn't end at being metabolized by gut bacteria; it actually marks the beginning of another fascinating journey. These prebiotic fibers are converted into postbiotic molecules like Short-Chain Fatty Acids (SCFAs), which include butyrate, propionate, and acetate. One could say this is where the true alchemy takes place within the gut microbiome. Butyrate, for example, is not just a byproduct; it's an essential nutrient for the cells lining our gut and has been associated with anti-inflammatory properties and potential anti-carcinogenic effects.(7)

An intriguing study by Singh et al. (2022) adds a layer of complexity to our understanding of butyrate and its production. When people consume fiber, specific butyrate-producing bacteria like Roseburia are upregulated in the gut. This upregulation doesn't just lead to an increase in butyrate alone; it sets off a cascade of metabolic activities, resulting in a rich cocktail of beneficial metabolites. In other words, feeding butyrate-producing bacteria can have a downstream effect that results in a complex mixture of metabolites, each contributing to gut health in its unique way.(8)

In Conclusion: The Symphony of Symbiosis

This conversion of prebiotic mushroom derived beta-glucans to postbiotic SCFAs is just one example among countless molecular transitions happening within the gut. The gut microbiome is like a bustling metabolic factory, continuously producing and transforming a plethora of substances that interact with our bodies in complex ways. This leads us to the importance of dietary diversity. Just as a rich biodiversity in a forest contributes to its health and resilience, the variety of plants and fungi we consume contributes to a robust microbial ecosystem within us. Eating a diverse range of plant-based foods ensures that our gut bacteria have a varied "menu" to choose from, allowing them to produce a range of postbiotic molecules that contribute to our health in numerous ways

In essence, maintaining a healthy microbiome is akin to preserving a forest's ecosystem. Every mushroom, like every bacterial strain in our gut, plays a vital role in maintaining balance and fostering resilience. The synergy of these diverse elements not only supports our immediate gut health but also contributes to the broader network of immune health in our bodies. As the leaves continue to fall and you find yourself enchanted by the diversity of mushrooms this season, remember that they offer more than just a culinary delight; they're a key ingredient in the complex recipe for long-term health.

What about ThaenaBiotic®


If you're fortunate enough to live near a forest abundant in edible mushrooms, or even just a grocery store that stocks a good variety, consider incorporating these magical fungi into your meals this fall. But what if foraging in the Pacific Northwest or preparing mushroom-based dishes isn't within your reach? That's where ThaenaBiotic® comes in—a revolutionary supplement that offers an incredibly complex mixture of prebiotics and postbiotics sourced from healthy donors.

Think of ThaenaBiotic® as your convenient, go-to source for boosting your microbiome when a trip to the woods or a culinary adventure isn't an option. Just like the mushrooms we've been discussing, ThaenaBiotic® provides a wide spectrum of beneficial prebiotics and postbiotics to nourish your internal microbial community.



  1. Davani-Davari, D., Negahdaripour, M., Karimzadeh, I., Seifan, M., Mohkam, M., Masoumi, S. J., Berenjian, A., & Ghasemi, Y. (2019). Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications. Foods (Basel, Switzerland)8(3). https://doi.org/10.3390/foods8030092
  2. Cheng, J., Zhang, G., Liu, L., Luo, J., & Peng, X. (2023). Anti-inflammatory activity of β-glucans from different sources before and after fermentation by fecal bacteria in vitro. Journal of the Science of Food and Agriculturehttps://doi.org/10.1002/jsfa.12997
  3. Kei, N., Wong, V. W. S., Lauw, S., You, L., & Cheung, P. C. K. (2023). Utilization of Food-Derived β-Glucans to Prevent and Treat Non-Alcoholic Fatty Liver Disease (NAFLD). Foods (Basel, Switzerland)12(17). https://doi.org/10.3390/foods12173279
  4. Cerletti, C., Esposito, S., & Iacoviello, L. (2021). Edible Mushrooms and Beta-Glucans: Impact on Human Health. Nutrients13(7). https://doi.org/10.3390/nu13072195
  5. Vetvicka, V., & Vetvickova, J. (2014). Immune-enhancing effects of Maitake (Grifola frondosa) and Shiitake (Lentinula edodes) extracts. Annals of Translational Medicine2(2), 14.
  6. Xu, J., Shen, R., Jiao, Z., Chen, W., Peng, D., Wang, L., Yu, N., Peng, C., Cai, B., Song, H., Chen, F., & Liu, B. (2022). Current Advancements in Antitumor Properties and Mechanisms of Medicinal Components in Edible Mushrooms. Nutrients14(13). https://doi.org/10.3390/nu14132622
  7. Campos-Perez, W., & Martinez-Lopez, E. (2021). Effects of short chain fatty acids on metabolic and inflammatory processes in human health. Biochimica et Biophysica Acta, Molecular and Cell Biology of Lipids1866(5), 158900.
  8. Singh, V., Lee, G., Son, H., Koh, H., Kim, E. S., Unno, T., & Shin, J.-H. (2022). Butyrate producers, “The Sentinel of Gut”: Their intestinal significance with and beyond butyrate, and prospective use as microbial therapeutics. Frontiers in Microbiology13, 1103836.