Dietary Protein Source Affects the Interplay between Gut Microbiota and Host Performance in Nile Tilapia

Dietary protein quality plays a key role in maintaining intestinal mucosal integrity, but also modulates the growth of luminal microorganisms. This work assessed the effect of dietary protein sources on the performance, gut morphology, and microbiome in Nile tilapia. Four isonitrogenous and isolipidic diets comprising equivalent amounts of the protein supply derived from either PLANT, ANIMAL, INSECT, or MICROBIAL (bacterial biomass) sources were fed to triplicate groups of fish (IBW: 12 g) during 46 days. Fish fed ANIMAL and MICROBIAL diets showed significantly higher growth than those fed the PLANT and INSECT diets (P < 0.05). Relative abundance at the phylum level shows Bacteroidetes, Fusobacteria and Proteobacteria as more abundant phyla in tilapia’s intestine, while Cetobacterium is the most representative genera in all treatments. Interesting patterns were observed in the correlation between amino acid intake and genus and species abundance. Metabolism prediction analysis showed that microbial amine and polyamine degradation pathways are modulated depending on diets. In conclusion, different protein sources interfere directly with the cross-talk of bacteria pathways and amino acid intake.