Beta-glucans themselves don’t fight disease. Instead, these compounds are able to stimulate or activate the other cells responsible for immunity. [2]

When beta-glucans enter the body, they mimic an invader, and are taken to task by “macrophages”, innate immune cells that engulf the beta-glucan and take them to the lymph nodes. There, they are broken down into smaller bits. The fragments are then released and bind to “natural killer cells” (and other immune cells) essentially “priming” them and allowing them to reach and react to pathogens much quicker.

Sort of like a Trojan Horse, except good for you!

There are two particularly interesting compounds that have been isolated from different strains of Turkey Tail, notably PSP (polysaccharide peptide) and PSK (polysaccharide-k, otherwise known as “Krestin”).

PSK was discovered in the 1960’s in Japan and PSP was isolated in China in the 1980’s. These compounds have been studied for their ability to support the immune system and alleviate the side effects of chemotherapy*. 

A published review found that:

“PSK and PSP boosted immune cell production, ameliorated chemotherapy symptoms, and enhanced tumor infiltration by dendritic and cytotoxic T-cells*. Their extremely high tolerability, proven benefits to survival and quality of life, and compatibility with chemotherapy and radiation therapy makes them well suited for cancer management regimens*.” [3]

There have also been multiple studies on the use of PSK as being a beneficial adjunct to chemotherapy for various types of cancers*. 

“PSK has been studied in patients with gastric cancer, breast cancer, colorectal cancer, and lung cancer. It has been used as adjuvant therapy in thousands of cancer patients since the mid-1970s. PSK has been safely used in people for a long time in Japan and few side effects have been reported.” [4]

Turkey Tail has prebiotic properties and has traditionally been used for improving gut health*.

Studies have shown that Turkey Tail, more specifically PSP, has a prebiotic effect and has been shown to modify human fecal microbiota composition*. [5]

Another study looked to compare the effects of PSP to those of the antibiotic amoxicillin on the human gut microbiome*. [6]

It found that “PSP from T. versicolor acts as a prebiotic to modulate human intestinal microbiome composition*.”

Turkey Tail is more than just a carrier for immune-supporting beta-glucans – it also contains an impressive array of antioxidants, including phenols and flavonoids*. 

One study identified a total of 38 phenolic compounds. [7]

“These findings have demonstrated considerable potential of T. versicolor water extract as a natural source of antioxidants*.”

Extracts of Turkey Tail have been shown to exhibit anti-viral properties*.

Use of Turkey Tail supplementation has been reported to improve the immune status of patients with HIV [8] and reduce the frequency and inactivate herpes simplex virus in a dose-dependant manner*. [9]