Uncovering the Fascinating History of Shiitake Fungi: From Ancient Origins to Modern Cultivation

What are Fungi?

Fungi, often mistaken for plants, form their own individual distinct kingdom, encompassing mushrooms, toadstools, and mould. Interestingly, genetic research reveals a closer relationship between fungi and animals than plants. Unlike plants, fungi lack chlorophyll; their cell walls are composed of chitin instead of cellulose. The fungal kingdom boasts many organisms, varying in life cycles and forms, from single-celled aquatic species to large mushrooms. Fungi are typically noticed during fruiting when they produce mushrooms or toadstools. Larger fungi develop mycelium, a network of delicate, branching, thread-like roots commonly found in organic-rich soil. Fungi obtain nutrients from organic matter, including plant and animal waste, playing a crucial role in nutrient recycling, especially in soil ecosystems.

 

History

The association between humans and fungi was evidenced around 18,700 years ago, when El Miron, a highly regarded Elder in Cantabria, Northern Spain, was buried. Her tomb was marked with red pigment and decorated with a garland of yellow blooms and plaque from her teeth was analysed and found to have two types of fungi present, Agaricales and Boletaceae. This became the earliest instance of fungi consumption, although it remains unclear to archaeologists whether it was used as nourishment, medication, or for other intentions. Later, the preserved remains of Otzi the Iceman, dating back 5,300 years ago, were discovered. In his possession, they found Piptoporus betulinus or Fomitopsis betulina (birch polypore), potentially used as a purgative or for worm expulsion. The polypore's skin could be removed to make an early but effective type of plaster. Also, evidence of Fomes fomentarius (tinder fungus) was found, which could have assisted in igniting fires.

Smashing Shiitake

Shiitake mushrooms, Lentinula edodoes, are a popular edible mushroom native to East Asia which is cultivated and consumed across the world and has been used in both herbal medicine and in some forms of traditional medicine. The earliest records of cultivating shiitake dates back to Song dynasty in China in 1209 where a 185-word description was written on the cultivation of the shiitake mushroom.  During ancient times in China and Japan, it was a common practice to place Shiitake-inoculated logs near a child during birth. As the child grew into adulthood, the logs would also mature, symbolising the growth of their 'backyard fortune'. This tradition led to a high value being placed on Shiitake mushrooms, often resulting in fierce competition between families, known as the 'shiitake war'. The scientific and medicinal focus has been on two extracts of the Shitake fungi, with lentinan being the primary compound of interest. This high molecular weight polysaccharide is derived from the cell walls of the fruiting bodies (mycelia) and consists of glucose molecules arranged in a triple helix structure. First isolated back in 1969, lentinan was noted for its potent antitumor properties surpassing those of other mushroom polysaccharides. Rather than directly attacking tumour cells, it enhances the host's immune system in various ways, such as activating natural killer cells, promoting the transformation of blood lymphocytes into lymphokine-activated killer cells, and boosting the production of natural interferon and interleukin.

 

Polysaccharides are generally indigestible to humans, due to the fact that they’re large molecules with branches and links, they’re unable to cross the cell membrane into the blood stream. However, their physical movement through the colon appears to trigger specific physiological reactions in humans, possibly due to the immune reactions from the clusters of subepithelial lymphoid follicles found in the intestines reactions. A number of polysaccharides, notably beta-glucans, are known to possess immunoregulatory effects and the ability to stimulate cytokines. These small proteins are vital in directing the behaviour and development of other cells within the immune system and bloodstream. Cytokines not only influence the growth of all blood cells but also play a significant part in the body's defence mechanisms and inflammatory response.