Dietary supplementation of two indigenous Bacillus spp on the intestinal morphology, intestinal immune barrier and intestinal microbial diversity of Rhynchocypris lagowskii

This study evaluated the effects of dietary administration of two indigenous Bacillus (A: basal control diet; B: 0.15 g/kg of Bacillus subtilis ; C: 0.1 g/kg of Bacillus subtilis and 0.05 g/kg of Bacillus licheniformis ; D: 0.05 g/kg of Bacillus subtilis and 0.1 g/kg of Bacillus licheniformis ; E: 0.15 g/kg of Bacillus licheniformis ) on the digestive enzyme activities, intestinal morphology, intestinal immune and barrier-related genes relative expression levels, and intestinal flora of Rhynchocypris lagowskii . The results showed that the fold height, lamina propria width, and muscle layer thickness of midgut and hindgut in group C were significantly higher than that of group A ( P