Effects of Dietary Supplementation with <i>Bacillus subtilis natto</i> on Growth, Digestive Enzyme Activity, Immune Response, and Intestinal Microorganisms of Red Sea Bream, <i>Pagrus major</i>

Abstract

This study investigated the influence of dietary supplementation with Bacillus subtilis natto (BSN) on various physiological parameters in red sea bream (Pagrus major). Key areas of focus included growth performance, enzymatic activity related to digestion, blood biochemical markers, immune function, and intestinal microorganisms. Fish were fed diets containing the following five levels of BSN: 0 (BN0), 1 × 107 (BN1), 1 × 108 (BN2), 1 × 109 (BN3), and 1 × 1010 (BN4) CFU kg−1 for 56 days. Fish in the BN3 and BN4 groups exhibited significantly enhanced growth performance compared to the BN0 group (p p p p p B. subtilis and Lactobacillus, along with a notable decrease in Escherichia coli, compared to all other groups (p 9 and 1 × 1010 CFU kg−1 shows promise in improving the growth, health, and immune response of red sea bream.

Keywords

• <i>Bacillus subtilis natto</i>
• red sea bream
• intestinal microorganisms
• immune response