Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: A double-blind, placebo-controlled trial  

In 2008 this double-blind placebo controlled trial had 21 healthy, adult volunteers over the course of 4 weeks. Half of the volunteers were given a placebo and half were given 3g of AHCC daily.  The study found that individuals taking AHCC had 55% more dendritic cells after 4 weeks than at baseline, and that they had 66% more than individuals taking a placebo. 

References:

Terakawa N et al. Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: A double-blind, placebo-controlled trial. Nutrition and Cancer. 2008; 60(5): 643-651.