This study investigates the effects of different levels of commercial yeast glucan (CYG) on innate immune response, hematological parameters, intestinal microbiota, growth performance and survival rate of white fish (kutum) fry. Specimens (1.1 ± 0.15 g) were randomly allocated into 15 tanks (100 L) at a density of 25 fish per tank and triplicate groups were fed either a basal control diet (0% CYG) or a basal diet supplemented with yeast (0.5, 1, 1.5 or 2% CYG) for 60 days. All dietary CYG levels significantly increased the innate immune responses (IgM levels and lysozyme activity) (P < 0.05) and the highest survival was observed in the 1 and 1.5% CYG group. Compared to the control group, CYG had no effects on RBC, Hct and Hb (P > 0.05), but WBC levels were significantly higher in CYG fed fish (P < 0.05). Microbiological assessment indicated that the viable culturable autochthonous and lactic acid bacteria (LAB) levels significantly elevated in 0.5 and 1% treatments. Our results indicated that low levels of dietary CYG (0.5 and 1 %) improved growth performance, body protein levels and survival rate compared to the control treatment (P < 0.05). These results indicate that CYG stimulates innate immune response, improves growth performance and modulates intestinal microbiota of kutum fry. Thus, we suggest that low level CYG may be used as a beneficial dietary supplement in kutum fry culture.