So you’re interested in taking mushroom supplements - whether that be for dietary reasons, wanting to incorporate adaptogens, or for specific compounds found in mushrooms - and you notice that certain supplements mention mycelium, but others don’t, and are now wondering why that is. That’s what we’ll clear up in this article. But first, we need to go over what the difference is between a fungi’s mycelium and its fruiting body (which is what we call the mushroom).
The fruiting body of a fungus (primarily basidiomycetes, although there are some rare exceptions) is what we typically call mushrooms in lay terms and what we commonly see sold in the supermarkets in the produce aisle. Its main purpose is to reproduce and help spread the spores of a fungus so that they can colonize elsewhere and continue growing, and is the final part of a fungi’s life cycle in some cases (though many mycelium will continue to live and produce mushrooms as long as there is substrate left with the nutrients it needs). Essentially, the fruiting body - the mushroom - is only the reproductive part of a fungus. It tends to be rich in nutrients as that is where the mycelium sends the “food” it eats from its substrate in order to form its spores. The mushroom also tends to be very rich in fungal Beta-glucans, as the cell walls of the fruiting body are thick in order to be able to survive the outside environment better. You’ll find on average over 10x more fungal Beta-glucans in the fruiting body than you will in mycelium that’s been growing in substrate.[1]
This on the other hand is the rest of the body of the fungus. It lives inside the substrate and feeds off it. It is formed once spores find a suitable substrate to grow on, and, with the right conditions, sprout hyphae, which are essentially a fungi’s roots. Once these hyphae grow enough and connect, only then do they specialize and become mycelium. Mycelium are very low in Beta-glucans, as they must be thinner and porous in order to absorb water and nutrients from the substrate. They themselves also don’t contain many nutrients, as excess nutrients that the mycelium collects go directly to growing more hyphae or, if the conditions are right, towards forming a mushroom. They do however contain some different compounds than the mushroom, as most of a fungi’s immune and digestive system is located in the mycelium in order to filter out waste and to fight off competing bacteria that are also trying to decompose the substrate that the fungus is living in. I’d like to clarify however that a fungi’s immune system works drastically different than ours, and tends to fight off bacteria, viruses, and even other competing fungi by producing antibacterial, antiviral, and antifungal compounds instead. Most fungi derived antibiotics used in medicine for this reason extract the antibiotic from the mycelium.[2]
So this is where you may now notice that some supplements mention they contain mycelium. Most of the time it will be labeled if it contains it due to regulation agencies (such as the FDA) requiring it to do so, but not always. The reason for this is because themycelium is inseparable from the substrate.This can result in supplements that use fungal substrate to have a lot of filler ingredients that offer no benefit or nutritional value, since many fungi are grown in simple starches or composted grasses. Thus, if you are trying to take mushroom supplements for certain benefits such as Beta-glucans, not only will you be getting less of them since the mycelium does not store many nutrients in the first place, nor does it contain significant amounts of Beta-glucans, but also because you’ll just be taking starches and other indigestible filler that is also nutritionally devoid (as the nutrients have already been used by the mycelium itself or to form a mushroom).
Extracts typically are made from only the fruiting body, since heat is needed to unbind and concentrate certain compounds from the thick cell walls[3]. If the Myceliumis thrown in with the fruiting body, very little benefit will be gained from doing so as the heat will affect the mycelium greater due to it having thinner and more porous walls and as such damage or destroy most of the compounds it contains. That is why if an extract is made with the mycelium in mind, it will usually be very specifically labelled, as the maker of the extract is trying to concentrate a compound perhaps only found in the mycelium, and will be doing a cold extraction instead that normally uses ethanol or water mixed with some other liquid which contains a low evaporative temperature. Mycelium extracts also tend to be devoid of all nutrients as well, although extracts made from the fungal fruiting bodies are also often low on nutrients as well because of the heat processing, with only mushroom powders keeping most nutrients intact.
Without a doubt, in this case, you should always choose supplements made only with, or with as much as possible of, the fruiting body. You want to avoid supplements which contain mycelium, as that means you will inevitably get useless fillers as well. Here at Peak and Valley, we only use mushroom fruiting body extracts in our supplement mixtures for that reason. However, if you’re shopping around for pure mushroom supplements, there’s a few things to keep in mind if you’re looking to make sure you don’t spend money on nutritionally devoid fillers:
In all, always pick supplements that use the actual mushroom and not the mycelium when possible. A final reason to also choose the mushroom itself over the mycelium is because most scientific studies and research done uses the fruiting body and/or its extract, not the mycelium. Despite the mycelium perhaps having some unique compounds itself, there will be extremely little scientific evidence when it comes to health benefits simply due to how much of the research of basidiomycetes is currently focused on their fruiting bodies.
1: Mccleary, B. V., & Draga, A. (2016). Measurement of β-Glucan in Mushrooms and Mycelial Products. Journal of AOAC INTERNATIONAL, 99(2), 364-373. doi:10.5740/jaoacint.15-0289
2: Gougouli, M., & Koutsoumanis, K. P. (2013). Relation between germination and mycelium growth of individual fungal spores.International Journal of Food Microbiology, 161(3), 231-239. doi:10.1016/j.ijfoodmicro.2012.12.006
3: Unger, S. E., Vincze, A., Cooks, R. G., Chrisman, R., & Rothman, L. D. (1981). Identification of quaternary alkaloids in mushroom by chromatography/secondary ion mass spectrometry. Analytical Chemistry, 53(7), 976-981. doi:10.1021/ac00230a012