Microbiome & immune support. Powered by mushroom mycelium. Turkey Tail (Trametes versicolor). Microbiome & Immune Support. A natural prebiotic, Turkey Tail is one of the most-studied mushroom species, well-known for benefiting microflora in the gastrointestinal ecosystem and for supporting a balanced immune response. Turkey Tail. Supports beneficial microflora in the gut microbiome. Promotes digestive and gastrointestinal health. Supports an engaged and balanced immune response. No 1 best selling mushroom brand in the U.S (Source: Spinsscan Natural/Natural Products Supermarkets greater than $2MM/Total US - Natural Channel/Mushrooms Ingredient Report/52 Wks Ending 9/5/2021). Paul Stamets. Fungi perfecti. LLC. Powered by mushroom mycelium. Fungi perfecti-makers of host defense mushrooms-was founded by renowned mycologist Paul Stamets to build a bridge between people and fungi. We specialize in mycelium-based supplements for immune support and whole-body wellness. Sustainably grown in the USA, our mushroom mycelium is cultured on organic brown rice. Host Defense formulations are based on scientifically validated data to ensure quality and safety. - Paul Stamets. Our choices matter. Bee friendly. Eco packaging.