Bioavailability and Digestibility of Nutrients from the Dried Oyster Culinary-Medicinal Mushroom, Pleurotus ostreatus (Agaricomycetes): In Vivo Experiments.

There is a limited number of publications on the bioavailability and digestibility of nutrients contained in macrofungi. The aim of this study was to assess the bioavailability and digestibility of macronutrients using in vivo experiments on laboratory animals. The experiments were conducted with the commercial oyster mushroom Pleurotus ostreatus. Semisynthetic diets were prepared based on the modified AIN-93M diet and were supplemented with 4% and 8% mushroom powder. Between days 4 and 13, apparent digestibility indexes were determined for all animals using the conventional balance method. The hematological indexes-that is, hemoglobin, hematocrit, red blood cells, white blood cells, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration-were determined using a Sysmex K-1000 hematological analyzer. Feeding rats with semisynthetic diets supplemented with dried oyster mushroom had no negative effect on body weight gain or feeding efficiency, expressed in the amount of body weight gain per unit of metabolic energy uptake. Introduction of dried oyster mushroom to the diet resulted in reduced digestibility of the diet and the protein and fat it contained, as well as decreased apparent energy availability. These changes were dependent on the volume of dried mushroom added to the semisynthetic diet. The addition of dried oyster mushroom to the semisynthetic diet considerably reduced passage time through the alimentary tract of rats.