What’s in Your Shroom? The Difference Between Fruiting Body and Mycelium
Functional mushrooms are a $540 million industry. It’s expected to grow 15% from 2024 to 2030, because people are choosing more natural ways to care for their health.
There’s a plethora of choices right now, and you won’t have trouble finding options. But there’s also a debate about the standard of quality of mushroom supplements in the US market. Particularly, it’s a debate between mycelium on grain and fruiting body-based supplements.
The difference is noticeable. Let’s discuss.
What’s the Difference Between Mycelium and Fruiting Body?
And why do some brands prefer mycelium-only or fruiting body-only supplements?
Mycelium
Mycelium are threads that are like roots growing underground. The mushroom secretes enzymes through the mycelium to break down the substrate, which is normally grain, but it can also be barley, soil, dead wood, and other organic or decaying matter. The broken-down compounds are then absorbed for growth and other metabolic activity.
It’s what triggers the formation of a fruiting body. While mycelium grows, it produces substances like metabolites and enzymes that act as antibiotics, antivirals, and antifungals to protect the mushroom.
Fruiting Body
The fruiting body is the more familiar part of the mushroom that you see above the soil, like the cap and stem. While it’s made up of up to 95% water, it’s more dense in nutrients compared to mycelium.
More importantly, it’s rich in polysacharides like beta-glucans, triterpenoids, polyphenols, and peptides. These key components give mushrooms their cancer-fighting, stress managing, and gut health properties, among others.
The Metabolites Factor
A study conducted by Berger, et. al. showed a comparison of metabolites between mycelium and the fruiting body. Metabolites are studied for their potential medicinal properties.
Here are some of the findings.
|
Component |
Mycelium |
Fruiting Body |
|
Protein content |
Similar to a fruiting body |
24-48% (Agaricus) 15-33% (Pleurotus) 10-20% (Lentinula) |
|
Beta glucans |
Present but study notes polysaccharides from mycelium "can be an effective substitute." |
Present |
|
Glutamic acid Contributes to the umami flavor |
Highest in button and oyster mushrooms |
12.8-18.7% in oyster mushroom and 20.9% in shiitake mushroom. |
|
Polysaccharides - Composition |
Mainly glucose (A. bisporus) |
Mainly mannose (A. bisporus) |
|
Ergosterol |
Higher concentrations |
Lower concentrations |
|
Linoleic Acid |
16% |
55.5% |
|
Lovastatin |
0.51 mg/100g dry mass (released into digestive juices) |
~1 mg/100g dry mass |
|
Iron (Fe) |
119-312 μg/g dry mass (tryptophan enriched cultures) |
14-160 μg/g dry mass |
Why Is Fruiting Body Preferred?
There are several studies showing strong data that mycelium can offer the same substantial nutritional benefits. But many brands and consumers still favor the fruiting body.
FreshCap uses 100% fruiting body, and it’s easy to know why. It also tests for safety in every batch, every time.
Here are a few reasons:
It’s Preferred in Clinical Research and Traditional Chinese Medicine
Most traditional and clinical research on medicinal mushrooms focused on the fruiting body as the source of bioactive compounds. This creates a strong reputation for the fruiting body.
Clinically speaking, some regulatory and quality testing standards for beta-glucans and triterpenes are based on the fruiting body’s specific profile.
Fruiting Body Has Higher Concentrations of Bioactives
Bioactives are your beta-glucans, triterpenes, and polysaccharide-K. These beta-glucans are well-studied for their potential in immune system support, blood sugar control, cholesterol reduction, anti-inflammatory, anti-cancer, and anti-microbial effects, among others.
Lion’s mane supplements have more than 25% beta-glucans and polysaccharides, while turkey tail has up to 30% beta-glucans. There’s a lot less of these properties in mycelium.
Freshcap uses 100% fruiting bodies for all its supplements and powders, including Lion's Mane, Reishi, Turkey Tail, and the Ultimate Mushroom Complex that includes up to 6 types of mushrooms.
Are Commercial Mycelium-Based Supplements Low Quality?
Not every mycelium-based mushroom supplement out there is of low quality. The main concern for mycelium-based mushroom supplements lie in the substrate used, often labeled as “mycelium on grain” in the packaging. These often have fillers that dilute the bioactive component..
Grains provide a nutrient-rich medium for rapid growth, but there’s an ongoing discussion about residual starch content that may dilute the bioactives.
Research and industry sources agree that when mycelium is cultivated on grains or starch pulp, a significant portion of the final dried product often consists of residual substrate (mostly starch), not pure fungal biomass. This can markedly dilute the bioactive mushroom compounds, reducing levels of desired ingredients such as beta-glucans, triterpenes, and polysaccharide-K
Manufacturers choose mycelium based on the following:
- It’s easier and faster to grow
Mycelium can grow as fast as 20 days, but typically 2-4 weeks, depending on the substrate. The substrate or growing medium is typically grain, but it can also be sawdust, wheat, barley, straw, or compost.
- It’s less expensive to grow
It can be rapidly grown in sterile bags or trays using simple agricultural materials, minimal space, and labor. Equipment and facility requirements are less demanding than for fruiting bodies, which need more precise controls (light, humidity, temperature, CO2 levels) and longer maturation.
- It has its unique properties, Erinacines.
In lion’s mane, Erinacines are produced almost exclusively by the mycelium. It’s highly studied for neuroprotective, nootropic, and regenerative effects. In contrast, the fruiting body also has these properties, but they’re given by a different compound called Hericenones. Thus, Lion’s mane’s scientific name, Hericenones erinacines.
Fruiting Body as the Gold Standard in Mushroom Supplements
The use of grain or starch-based substrates for mycelium cultivation can significantly dilute the content of mushroom bioactives in supplements, unless careful separation, extraction, and testing are performed.
Quality brands will specify the biomass percentage and substrate content, while reputable supplements use extraction methods that minimize or remove excess starch.
Be cautious of products labeled only as "mycelium on grain”. The active mushroom content may be much lower than expected unless independently tested for actual active ingredients.
There’s nothing wrong with mycelium, but it’s a lot more difficult to know how they’re produced to bring high-quality products to the shelves. That’s why fruiting body-based mushroom supplements remain as the gold standard in nootropic products.
