Clostridium butyricumas probiotic for promoting growth performance, feed utilization, gut health and microbiota community of tilapia (Oreochromis niloticus × O. aureus)

The feeding trial was conducted to evaluate the potentials of Clostridium butyricum in the diet of tilapia. Fish (~14 g) were fed with basal diet supplemented with 0 (Control), 0.5 (C-1), 1 (C-2), 2 (C-3), 4 (C-4) and 8 (C-5) g/kg commercial probiotic-containing C. butyricum (1.5 × 108 CFU/g) for 8 weeks. The results showed that weight gain significantly increased, and feed conversion ratio decreased in the C-2, C-3 and C-4 groups (p < .05). The protein retention (except C-1 group), lipid retention and apparent digestibility coefficient (ADC) of dry matter in probiotic supplementation groups were significantly enhanced, and ADC of protein in the C-4 group was also improved (p < .05). The supplementation of probiotic significantly increased villus height in anterior intestines and reduced the numbers of intestinal Escherichia coli (p < .05). High-throughput sequencing showed that top three phyla namely Planctomycetes in all probiotic-containing groups, Proteobacteria in the C-1 and C-2 groups and Chloroflexi in the C-3 group had higher level than the NC group. The cumulative mortality was reduced by dietary probiotic after challenging with Aeromonas hydrophila (p < .05). In conclusion, C. butyricum can be supplemented at 1–2 g/kg feed for promoting the growth, feed utilization, gut health and microbiota of tilapia.