Study design
A randomized, double-blind, placebo-controlled, cross-over study design was used for this clinical study (clinical trial registration ISRCTN14647763), which was conducted in accordance with the Declaration of Helsinki, and approved by the Argus Independent Review Board, Tucson AZ, USA. The sample size was determined based on previous studies on acute effects of nutraceuticals containing similar doses of beta-glucans and other immune-activating botanical and fungal polysaccharides. Based on the expected effects on innate immune cell types, we aimed for a minimum of 10 people completing the study participation [